High-fat foods tend to stay in the stomach longer, and the longer they're there, the more likely discomfort can be, note Bonci and Elaine Magee, MPH, RD, author of Tell Me What to Eat If I Have Acid Reflux. And if you're eating big servings of those high-fat foods -- like a lot of fried chicken, chips, or wings -- then you've got a double whammy of two potential heartburn triggers -- too much food and fatty fare.
Saturday, March 30, 2013
High-fat foods tend to stay in the stomach longer, and the longer they're there, the more likely discomfort can be, note Bonci and Elaine Magee, MPH, RD, author of Tell Me What to Eat If I Have Acid Reflux. And if you're eating big servings of those high-fat foods -- like a lot of fried chicken, chips, or wings -- then you've got a double whammy of two potential heartburn triggers -- too much food and fatty fare.
Friday, March 29, 2013
Always eating in a hurry? Shoveling food down is also a no-no, if you want to tame heartburn. Leslie Bonci, MPH, RD, CSSD, director of sports nutrition at the University of Pittsburgh Medical Center, says the three G's -- grab, gulp, and go -- don't make for good digestion and can make GERD (gastroesophageal reflux disease) symptoms more likely. Heartburn is a GERD symptom. So slow down when you eat if you're concerned about heartburn symptoms.
The first thing to think about, in terms of curbing heartburn, isn't this or that specific food. It's the amount of food you eat at a time. When it comes to heartburn risk, the sheer volume of what you eat matters. And this is one case where bigger isn't better. No matter what the food is, how good it looks, or how much you like it, eating too much food at once makes heartburn more likely. Tip: Try using smaller plates to trim your portions
Good question -- and the answer might not be what you expect. First, here are a few basic facts about heartburn, which has nothing to do with the heart. Heartburn is a burning discomfort from the chest area up to the throat. It can happen when stomach acid refluxes, or flows up, through a valve called the lower esophageal sphincter and irritates the esophagus. Certain foods can trigger heartburn, but you may have a little more food freedom than you think, if you consider the pointers in this slideshow.
Thursday, March 28, 2013
Bisoprolol is a drug belonging to the group of beta blockers, a class of drugs used primarily in cardiovascular diseases. More specifically, it is a selective type β1 adrenergic receptor blocker. The FDA approved Duramed Pharmaceutical's application for Zebeta Oral Tablets as a new molecular entity on July 31, 1992. It has since been approved by the FDA for manufacture by Teva, Mylan, Sandoz, and Mutual Pharmaceutical Company.
Bisoprolol is used to treat high blood pressure, reduced blood flow to the heart (cardiac ischemia); congestive heart failure, preventative treatment before and primary treatment after heart attacks decreasing the chances of recurrence. During hypertension there is an elevated blood pressure, which is what bisoprolol targets. While in cardiac ischemia the drug is used to reduce the activity of the heart muscle and therefore reduce oxygen and nutrient demand, so reduced blood supply can still transport sufficient amounts of oxygen and nutrients.
Many beta-blockers are now available and in general they are all equally effective. There are, however, differences between them which may affect choice in treating particular diseases or individual patients.
Beta-blockers with a relatively short duration of action have to be given two or three times daily. Many of these are, however, available in modified-release formulations so that administration once daily is adequate for hypertension. For angina twice-daily treatment may sometimes be needed even with a modified-release formulation. Some beta-blockers such as atenolol, bisoprolol, carvedilol, celiprolol, and nadolol have an intrinsically longer duration of action and need to be given only once daily.
SIDE EFECTS - Overdose of bisoprolol leads to fatigue, hypotension, low blood sugar, bronchospasms and bradycardia. Bronchospasms and low blood sugar because at high doses drug can be an antagonist for β2 adrenergic receptors located in lung and in liver. Bronchspasm due to blockage in lungs of β2 receptor and low blood sugar because of decreased stimulation of glycogenolysis and gluconeogenesis in the liver via β2 receptor.
MECHANISM OF ACTION
Bisoprolol is cardioprotective because it selectively and competitively blocks catecholamine (adrenalin) stimulation of β1 adrenergic receptors (adrenoreceptors), which are mainly found in the heart muscle cells and heart conduction tissue (cardio specific) but also found in juxtaglomerular cells in the kidney. Normally adrenalin and noradrenalin stimulation of the β1 adrenoreceptor activates a signalling cascade which ultimately lead to increased contractility and increased heart rate of the heart muscle and heart pacemaker respectively. Bisoprolol competitively blocks the activation of this cascade and therefore decreases the adrenergic tone/stimulation of the heart muscle and pacemaker cells. Decreased adrenergic tone shows less contractility of heart muscle and lowered heart rate of heart pacemaker.
These are the favourable factors that are decreased and treat hypertension, heart attacks and ischemia. The decreases in contractility and heart rate are beneficial for hypertension because they reduce blood pressure but for preventive measures for heart attacks and cardiac ischemia these decreases in heart rate and contraction decrease the hearts demand for oxygen and nutrients; primary treatment post heart attacks is to prevent recurrence of the infarction.
Major drug interation with - Theophylline, diltiazem, atazanavir, GUIFENESIN, EFEDRIN,
A. Beta-Blockers (including Bisoprolol) - IN ASMA / COPD
In general, beta-adrenergic receptor blocking agents (i.e., beta-blockers) should not be used in patients with bronchospastic diseases. Beta blockade may adversely affect pulmonary function by counteracting the bronchodilation produced by catecholamine stimulation of beta-2 receptors. If beta-blocker therapy is necessary in these patients, an agent with beta-1 selectivity (e.g., atenolol, metoprolol, betaxolol) is considered safer, but should be used with caution nonetheless. Cardioselectivity is not absolute and can be lost with larger doses.
B. Beta-Blockers (including Bisoprolol) - In Beta-Blockers (including Bisoprolol) - Bradyarrhythmia/Av Block
The use of beta-adrenergic receptor blocking agents (aka beta-blockers) is contraindicated in patients with sinus bradyarrhythmia or heart block greater than the first degree (unless a functioning pacemaker is present). Due to their negative inotropic and chronotropic effects on the heart, the use of beta-blockers is likely to exacerbate these conditions.
C. Beta-Blockers (including Bisoprolol) - In Cardiogenic Shock/Hypotension :
The use of beta-adrenergic receptor blocking agents (aka beta-blockers) is contraindicated in patients with hypotension or cardiogenic shock. Due to their negative inotropic and chronotropic effects on the heart, the use of beta-blockers is likely to further depress cardiac output and blood pressure, which can be detrimental in these patients.
D. Beta-Blockers (including Bisoprolol) - In Hemodialysis
Therapy with beta-adrenergic receptor blocking agents (aka beta-blockers) should be administered cautiously in patients requiring hemodialysis. When given after dialysis, hemodynamic stability should be established prior to drug administration to avoid marked falls in blood pressure. The hemodynamic status should be closely monitored before and after the dose.
E. Beta-Blockers (including Bisoprolol) - In Hypersensitivity
The use of beta-adrenergic receptor blocking agents (aka beta-blockers) in patients with a history of allergic reactions or anaphylaxis may be associated with heightened reactivity to culprit allergens. The frequency and/or severity of attacks may be increased during beta-blocker therapy. In addition, these patients may be refractory to the usual doses of epinephrine used to treat acute hypersensitivity reactions and may require a beta-agonist such as isoproterenol.
F. Beta-Blockers (Includes Bisoprolol) - Diabetes
Beta-adrenergic receptor blocking agents (aka beta-blockers) may mask symptoms of hypoglycemia such as tremors, tachycardia and blood pressure changes. In addition, the nonselective beta-blockers (e.g., propranolol, pindolol, timolol) may inhibit catecholamine-mediated glycogenolysis, thereby potentiating insulin-induced hypoglycemia and delaying the recovery of normal blood glucose levels. Since cardioselectivity is not absolute, larger doses of beta-1 selective agents may demonstrate these effects as well. Therapy with beta-blockers should be administered cautiously in patients with diabetes or predisposed to spontaneous hypoglycemia.
BRANDS - Available on the strength 5mg and 2.5mg
Bisbeta - Shrristhi Health Care Products Pvt Ltd
Biselect Intas Laboratories Pvt Ltd
Bisocar Rusan Healthcare Pvt Ltd
Bisod Medreich Saimirra Ltd
Concor Merck (India) Ltd
Zabesta US Vitamins Limited
Benidipine is a Calcium Antagonist it is also known as Benidipinum or benidipine hydrochloride, It is a dihydropyridine calcium channel blocker for the treatment of high blood pressure
DOSE - 2–4 mg once daily . Should be taken with food.
Benidipine is sold as Coniel by Kyowa Hakko Kogyo.
Benidipine is only licensed for use in Japan and selected Southeast Asian countries, where it is sold as 4 mg tablets.
O5-methyl O3-[(3R)-1-(phenylmethyl)piperidin-3-yl] 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate
Mechanism of action : The vasorelaxant effect of benidipine is due to its affinity towards dihydropyridine binding sites in calcium channels. Binding of benidipine with calcium channels inhibits calcium current. The onset of action is slow, which results in minimal tachycardia or palpitation.
Contraindications : Pregnancy and lactation.
Special Precautions : Elderly. In case of dizziness or lightheadedness, advise patients against handling of heavy machines or working at elevated spots. Reduce dosage gradually while withdrawing drug. Liver function tests.
Adverse Drug Reactions: Palpitation, facial flushing, hot flushes, chest pressure sensation, headache, dizziness, sleepiness, constipation, nausea, abdominal discomfort, oedema, malaise, tinnitus, redness and warm feeling in the fingers, shoulder stiffness, increased frequency of micturition. Hypersensitive reactions e.g. rash and itching. Elevation of SGOT, SGPT, alkaline phosphatase, total bilirubin, creatinine and uric acid.
Drug Interactions : β-blockers or diuretics may enhance BP control. Serum concentrations of digoxin may be increased. Cimetidine may inhibit benidipine metabolism.
Saturday, March 23, 2013
Benazepril is a medication used to treat high blood pressure, congestive heart failure, and chronic renal failure.
Most commonly, headaches and cough can occur with its use. Anaphylaxis, angioedema and hyperkalemia, the elevation of potassium levels, can also occur.
Benazepril may cause harm to the fetus during pregnancy.
Benazepril should be discontinued during pregnancy.
According to a 2006 article in the New England Journal of Medicine, patients with advanced renal insufficiency taking benazepril showed "substantial" kidney benefits.
A long-term study of patients' kidney disease revealed patients who took benazepril had better kidney function and slower progressions of kidney disease than their peers who took a placebo drug. This is notable because this category of pharmaceuticals has long been thought to cause further kidney damage or increase the rate of progression for kidney disease.
According to coverage of the study on WebMD:
"ACE inhibitors can pose a potential threat to kidneys as well. The key question was whether damaged kidneys would worsen if patients took ACE inhibitors. In a nutshell, concerns centered on blood levels of potassium and creatinine, waste products that are excreted by the kidneys. Testing creatinine levels in the blood is used as a way to monitor kidney function kidney problems worsened more slowly in those taking Lotensin. Overall, there were no major differences in side effects between patients taking Lotensin or the placebo. "
This study marks the first indication that benazepril, and perhaps other ACE inhibitors, may actually be beneficial in the treatment of hypertension in patients with kidney disease.
Wednesday, March 20, 2013
ATENOLOL is a β1 receptor antagonist, a drug belonging to the group of beta blockers, a class of drugs used primarily in cardiovascular diseases.
atenolol does not pass through the blood–brain barrier thus avoiding various central nervous system side effects.
Atenolol is one of the most widely used β-blockers in the United Kingdom and was once the first-line treatment for hypertension. The role for β-blockers in hypertension was downgraded in June 2006 in the United Kingdom to fourth-line, as they perform less appropriately or effectively than newer drugs, particularly in the elderly.
use - atenolol is used to treat acute myocardial infraction, angina, hypertension, supraventricular tachycardia, ventricular tachycardia
It is also used to treat the symptoms of Graves' disease until antithyroid medication can take effect.
Due to its hydrophilic properties, the drug is less suitable in migraine prophylaxis compared to propranolol, because, for this indication, atenolol would have to reach the brain in high concentrations, which is not the case.
Atenolol is also used sometimes to prevent migraine headaches and to treat alcohol withdrawal, heart failure, and irregular heartbeat. Talk to your doctor about the possible risks of using this medication for your condition.
Atenolol causes significantly fewer central nervous system side effects (depression, nightmares).
It was the main β-blocker identified as carrying a higher risk of provoking type 2 diabetes, leading to its downgrading in the United Kingdom in June 2006 to fourth-line agent in the management of hypertension.
In addition, β-blockers blunt the usual sympathetic nervous system response to hypoglycemia. These drugs therefore have an ability to mask a dangerously low blood sugar, which further decreases their safety and utility in diabetic patients.
Side effects include
indigestion, constipation, dry mouth, dizziness or faintness (especially cases of orthostatic hypotension)
cold extremities, impotence, rhinitis, depression, confusion, insomnia, nightmares
fatigue, weakness or lack of energy.
More serious side effects:
hallucinations, low blood pressure (hypotension), skin reactions, e.g. rash, hives, flaking of skin, worsening of psoriasis
sensation of 'pins and needles' hands or feet, irritated eyes, visual disturbances, difficulty hearing, difficulty speaking
unsteadiness when walking.
Before taking atenolol
tell your doctor and pharmacist if you are allergic to atenolol or any other medications.
tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: calcium channel blockers such as diltiazem (Cardizem, Dilacor, Tiazac, others) and verapamil (Calan, Isoptin, Verelan); clonidine (Catapres); nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin (Indocin); and reserpine (Serpalan, Serpasil, Serpatabs). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
tell your doctor if you have or have ever had asthma or other lung disease; diabetes; severe allergies; an overactive thyroid gland (hyperthyroidism); pheochromocytoma; heart failure; a slow heart rate; circulation problems; or heart or kidney disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking atenolol, call your doctor immediately.
if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking atenolol.
you should know that if you have allergic reactions to different substances, your reactions may be worse while you are using atenolol, and your allergic reactions may not respond to the usual doses of injectable epinephrine.
AB-NOL,ATEN, ALOTEN, ALTOL, ATCOM, ATECARD, ATORMIN, NENOL, BPNORM,CADPRES,CADTEN,EMBETA, HIBESOR,HIPRES, TENSIMIN,TENOLOL,
Monday, March 18, 2013
Amlodipine is a longacting calcium channel blocker, it used as an antihypertensive and in the treatment of angina pectoris. Amlodipine relaxing the smooth muscle in the arterial wall, decreasing total peripheral resistance thereby reducing blood pressure; in angina, Amlodipine increases blood flow to the heart muscle.
(RS) -3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4- (2-chlorophenyl) -6-methyl-1, 4-dihydropyridine-3, 5-dicarboxylate
Amlodipine taken orally. It is usually taken once a day. To help you remember to take amlodipine, take it around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take amlodipine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of amlodipine and gradually increase your dose.
Amlodipine controls high blood pressure and chest pain but does not cure them. Continue to take amlodipine even if you feel well. Do not stop taking amlodipine without talking to your doctor.
Initial dose is 5 mg daily (max, 10 mg daily). 2.5 mg daily when adding amlodipine to other antihypertensive therapy.
Children 6 to 17 years - 2.5 to 5 mg once daily.
Adults - 5 to 10 mg once daily.
Chronic stable or vasospastic angina
Adults - 5 to 10 mg once daily.
Elderly - Start with 5 mg once daily.
Initially 2.5 mg every day.
Chronic stable or vasospastic angina
Start with 5 mg once daily.
Elderly - Initially 2.5 mg every day.
MECHANISM OF ACTION
Amlodipine is a dihydropyridine calcium antagonist that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. Experimental data suggest amlodipine binds to both dihydropyridine and nondihydropyridine binding sites. The contractile processes of cardiac muscle and vascular smooth muscle are dependent upon the movement of extracellular calcium ions into these cells through specific ion channels. Amlodipine inhibits calcium ion influx across cell membranes selectively, with a greater effect on vascular smooth muscle cells than on cardiac muscle cells. Negative inotropic effects can be detected in vitro, but such effects have not been seen in intact animals at therapeutic doses. Serum calcium concentration is not affected by amlodipine. Within the physiologic pH range, amlodipine is an ionized compound , and its kinetic interaction with the calcium channel receptor is characterized by a gradual rate of association and dissociation with the receptor binding site, resulting in a gradual onset of effect.
Amlodipine is a peripheral arterial vasodilator acts directly on vascular muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure.
Amlodipine does also act as a functional inhibitor of acid sphingomyelinase.
The precise mechanisms by which amlodipine relieves angina have not been fully delineated, but are thought to include:
In patients with exertional angina, amlodipine reduces the total peripheral resistance against which the heart works and reduces the rate pressure product, so lowers myocardial oxygen demand, at any given level of exercise.
Amlodipine has been demonstrated to block constriction and restore blood flow in coronary arteries and arterioles in response to calcium, potassium, epinephrine, serotonin, and thromboxane A2 analog in experimental animal models and in human coronary vessels in vitro. This inhibition of coronary spasm is responsible for the effectiveness of amlodipine in vasospastic angina.
Amlodipine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
swelling of the hands, feet, ankles, or lower legs
headache , upset stomach , stomach pain , dizziness or lightheadedness
drowsiness , excessive tiredness , flushing (feeling of warmth)
Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:
more frequent or more severe chest pain
rapid, pounding, or irregular heartbeat
Administration's (FDA) MedWatch Adverse Event Reporting program online [at http:// If you experience a serious side effect, you or your doctor may send a report to the Food and Drug www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
Aforbes by Merck Inc. Philippines
Agen by Zentiva in the Czech Republic
Aken by Kendrick Farmaceutica in Mexico
Amcard in Bangladesh by Apex Pharma Ltd
Amdepin by Cadila Pharmaceuticals in India
Amdipin in Colombia by Laboratorios Lafrancol
Amlodine by Dainippon Sumitomo Pharmaceuticals in Japan, and in Philippines by Westfield Pharmaceuticals, a division of InnoGen
Amlodipine 5 in Indonesia by PT KALBE FARMA Tbk, Bekasi
Amlong in India by Micro Labs
Amlopin by Lek
Amlopin in Bangladesh by The Acme Laboratories Ltd
Amlopine in Thailand by Berlin (Thailand) Pharmaceutical Industry Co Ltd
Amlostin in the United Kingdom by Discovery Pharmaceuticals
Amlosun in Bangladesh by Sun Pharmaceutical (Bangladesh) Ltd
Amlovas in India by Macleods Pharmaceticals Ltd
Amlovasc in the United Kingdom by Dr. Reddy's Laboratories
Amlozek in Poland by Adamed
Asomex by Emcure Pharmaceuticals India
Atecard-AM in India by Alembic Ltd
Camlodin in Bangladesh by Square Pharmaceuticals Ltd
Dailyvasc by Xeno Pharmaceuticals
Hipril is a combination of lisinopril with amlodipine (5 mg each) in India
Istin in the United Kingdom and Ireland
Lama in India by Stadmed Private Limited, Kolkata
Lodopin in Pakistan by Merck Pakistan
Lopin in Bangladesh by Edruc Ltd
Nelod in Bangladesh by The Kemiko Pharmaceuticals Ltd
Nopidin in Bangladesh by Ad-din Pharmaceuticals Ltd
Norvasc by Pfizer in North America, some European countries, China, Japan, and Pakistan
Norvasc, Perivasc and Nordip in Australia
Pharex Amlodipine in the Philippines by PHAREX HealthCorp
Sunday, March 17, 2013
It is a non-proprietary combination of amiloride and hydrochlorothiazide. Co-amilozide is used in the treatment of hypertension and congestive heart failure with the tendency of the thiazide to cause low potassium levels (hypokalaemia) offset by the potassium-sparing effects of amiloride.
Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention.
Amiloride is a potassium sparing-diuretic that also prevents your body from absorbing too much salt and keeps your potassium levels from getting too low.
The combination of hydrochlorothiazide and amiloride is used to treat fluid retention (edema) and high blood pressure (hypertension).
Hydrochlorothiazide and amiloride may also be used for purposes not listed in this medication guide.
You should not use this medication if you have kidney disease, urination problems, diabetes, or high levels of potassium in your blood. Do not use potassium supplements while you are taking hydrochlorothiazide and amiloride.
Before using this medication, tell your doctor if you have heart disease, cirrhosis or other liver disease, glaucoma, a breathing disorder, gout, lupus, an allergy to sulfa drugs or penicillin, or a pancreas disorder. Tell your doctor if you use steroids or other blood pressure medicines.
Drinking alcohol can increase certain side effects of hydrochlorothiazide and amiloride.
Do not use salt substitutes or low-sodium milk products that contain potassium. These products could cause your potassium levels to get too high while you are taking hydrochlorothiazide and amiloride.
There are many other drugs that can interact with hydrochlorothiazide and amiloride. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.
Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.
Adult: Per tab contains amiloride hydrochloride 2.5 mg and hydrochlorothiazide 25 mg: Initially 1 tab daily, increased up to a max of 2 tabs daily as a single or divided dose. Per tab contains amiloride hydrochloride 5 mg and hydrochlorothiazide 50 mg: Initially 1/2 tab daily, increased up to a max of 1 tab daily as a single or divided dose.
Congestive heart failure - Oral
Adult: Per tab contains amiloride hydrochloride 2.5 mg and hydrochlorothiazide 25 mg: Initially 1 tab daily, increased up to a max of 4 tabs daily. Per tab contains amiloride hydrochloride 5 mg and hydrochlorothiazide 50 mg: Initially 1/2 tab daily, increased up to a max of 2 tabs daily. Reduce maintenance dose if possible.
Hepatic cirrhosis with ascites and oedema - Oral
Adult: Per tab contains amiloride hydrochloride 2.5 mg and hydrochlorothiazide 25 mg: Initially 2 tabs daily, increased up to a max of 4 tabs daily. Per tab contains amiloride hydrochloride 5 mg and hydrochlorothiazide 50 mg: Initially 1 tab daily, increased up to a max of 2 tabs daily. Reduce maintenance dose if possible.
Should be taken with food.
overdose - Symptoms include dehydration and electrolyte imbalance. Treatment is symptomatic and supportive.
Adverse Drug Reactions: Electrolyte imbalance e.g. hyponatraemia, hypochloraemic alkalosis, hypokalaemia and hypomagnesaemia. Anaphylaxis, back pain, chest pain, fatigue, fever, headache, malaise, neck/shoulder ache, pain in extremities, syncope, weakness; angina, arrhythmias, digitalis toxicity, orthostatic hypotension, necrotising angiitis, palpitation and tachycardia; GI disturbances; agranulocytosis, aplastic anaemia, haemolytic anaemia, leucopenia, neutropenia, purpura and thrombocytopenia; alopecia, diaphoresis, dry mouth, flushing, photosensitivity, pruritis, rash, sialadenitis and urticaria; glycosuria, gout, hyperglycaemia and hyperuricaemia; joint pain, leg ache and muscle cramps; dizziness, encephalopathy, paraesthesia, stupor, tremors, vertigo; decreased libido, depression, insomnia, mental confusion, nervousness, restlessness, sleepiness and somnolence; cough, dyspnoea and respiratory distress; bad taste, increased intraocular pressure, nasal congestion, tinnitus, visual disturbance and xanthopsia; bladder spasm, dysuria, impotence, incontinence, interstitial nephritis, nocturia, polyuria, renal dysfunction.
Drug Interactions Additive effects with other antihypertensives. May increase the responsiveness to tubocurarine. May reduce arterial responsiveness to pressor amines e.g. norepinephrine. Orthostatic hypotension may occur with alcohol, barbiturates and narcotics. Discontinue diuretics 2-3 days before initiation of an ACE inhibitor to reduce the likelihood of 1st dose hypotension. Increased hypokalaemia with corticosteroids or ACTH. Attenuation of diuretic, natriuretic and antihypertensive effects of diuretics with NSAIDs. Increased hyponatraemia with chlorpropamide. Increased hyperkalaemia with ciclosporin, tacrolimus, indometacin and angiotensin II receptor antagonists.
Potentially Fatal:Increases risk of hyperkalaemia with other potassium-sparing diuretics (spironolactone or triamterene). Increases risk of lithium toxicity.
You should not use this medication if you are allergic to hydrochlorothiazide or amiloride, or if you have:
kidney disease or are unable to urinate;
high potassium levels (hyperkalemia); or
if you are taking potassium supplements.
To make sure you can safely take hydrochlorothiazide and amiloride, tell your doctor if you have any of these other conditions:
diabetes; heart disease; cirrhosis or other liver disease; glaucoma; a breathing disorder; lupus; an allergy to sulfa drugs or penicillin; a pancreas disorder; or
if you are using another blood pressure medication or a steroid.
Friday, March 15, 2013
WHAT YOU SHOULD KNOW:
A heart healthy diet is an eating plan low in total fat, unhealthy fats, and sodium. A heart healthy diet helps to decrease your risk for heart disease. If you have already had a heart attack or stroke, a heart healthy diet may help to decrease your risk of having another heart attack or stroke.
Different types of fat in food:
Unhealthy fats: A diet that is high in cholesterol, saturated fat, and trans fat may cause unhealthy cholesterol levels. Unhealthy cholesterol levels increase your risk of heart disease.
Cholesterol:Limit intake of cholesterol to less than 200 mg per day. Cholesterol is found in meat, eggs, and dairy.
Saturated fat:Limit saturated fat to less than 7% of your total daily calories. Ask your primary healthcare provider how many calories you need each day. Saturated fats are found in butter, cheese, ice cream, whole milk, and palm oil. Saturated fat is also found in meat, such as beef, pork, chicken skin, sausage, hot dogs, and bologna.
Trans fat: Avoid trans fat as much as possible. Foods that say trans fat free on the label may still have up to 0.5 grams of fat per serving. Trans fats are used in fried and baked foods.
Healthy fats:Unsaturated fats can help to improve your cholesterol levels. Replace foods that are high in saturated and trans fats with foods that are high in the following kinds of fats:
Monounsaturated fats:These are found in avocados, nuts, and vegetable oils, such as olive, canola, and sunflower oil.
Polyunsaturated fats:These can be found in vegetable oils, such as soybean or corn oil. Omega-3 fats are a type of polyunsaturated fat that can help to decrease the risk of heart disease. Omega-3 fats are found in fish, such as salmon, herring, trout, and tuna. Omega-3 fats can also be found in plant foods, such as walnuts, flaxseed, soybeans, and canola oil.
Foods to limit or avoid:
Learn to read labels on packaged foods before you buy them. Ask your dietitian or primary healthcare provider for more information about how to read food labels. The following foods are high in fat, saturated fat, cholesterol, and sodium. Limit sodium to 2,300 mg per day. Sodium is found in table salt and foods that have added salt.
High-fat baked goods, such as doughnuts, pastries, cookies, and biscuits
Chips, snack mixes, regular crackers, and flavored popcorn
Fruit and vegetables:
Regular, canned vegetables (high in sodium)
Fried vegetables or vegetables in butter or high-fat sauces
Fried fruit or fruit served with cream
Whole milk, 2% milk, half-and-half creamer
Cheese, cream cheese, and sour cream
Meats and meat substitutes:
High-fat cuts of meat (T-bone steak, regular hamburger, and ribs)
Cold cuts, hot dogs, bacon, and sausage (high in sodium and fat)
Miso soup, canned or dried soups high in sodium
High-sodium sauces, such as soy sauce, ketchup, and barbecue sauce
High-fat gravy and sauces, such as Alfredo or cheese sauces
Foods you may eat and drink:
Ask your dietitian or primary healthcare provider how many servings to eat each day from each of the following groups of foods. The amount of servings you should eat from each food group depends on your daily calorie needs. Include whole-grains, fruits, vegetables, and legumes (beans) in your diet each day to get enough fiber.
Whole-grain breads, cereals, pasta, and brown rice
Low fat, low-sodium crackers and pretzels
Fruits and vegetables:
Fresh, frozen, or canned vegetables (no salt, or low-sodium)
Fresh, frozen, dried, or canned fruit (canned in light syrup or fruit juice)
Nonfat (skim) or 1% milk
Nonfat, low-fat cheese, yogurt, and cottage cheese
Meats and meat products:
Poultry (chicken, turkey) with no skin
Lean beef and pork (loin, round, extra lean hamburger)
Beans and peas, unsalted nuts, soy products
Egg whites and substitutes
Herbs and spices in place of salt
Low-fat and low sodium snacks (unsalted pretzels, plain popcorn)
Other guidelines to follow:
Eat foods that contain omega-3 fats: Eat 2 servings of fish per week. One serving is about 4 ounces. Fish is a good source of healthy omega-3 fats. Most fish contain some mercury, but many contain levels that are not harmful to most people. Higher amounts of mercury can be harmful to pregnant women and children. Children and pregnant women should avoid eating fish high in mercury, such as shark or swordfish. Fish that have lower amounts of mercury include salmon, canned light tuna, and catfish.
Maintain a healthy weight: Your risk of heart disease is higher if you are overweight. Your primary healthcare provider may suggest that you lose weight if you are overweight. You can lose weight by eating fewer calories. Eat fewer foods that have added sugars and fat, such as soda, candy, cakes, cookies, and pies. Decrease calories by eating smaller portions at each meal and fewer snacks. Ask your primary healthcare provider for more information about how to lose weight.
Exercise regularly:Regular exercise can help you reach or maintain a healthy weight. Regular exercise can also help improve your cholesterol levels and decrease your risk for coronary artery disease. Get 30 minutes or more of moderate exercise, or 20 minutes of intense exercise on most days of the week. Include muscle strengthening activities 2 days each week, such as push-ups, sit-ups, and lifting weights. To lose weight, get at least 60 minutes of exercise on most days of the week. Children should exercise for at least 60 minutes each day. Talk to your primary healthcare provider about the best exercise program for you.
Limit alcohol:Women should limit alcohol to 1 drink a day. Men should limit alcohol to 2 drinks a day. A drink of alcohol is 12 ounces of beer, 5 ounces of wine, or 1½ ounces of liquor.
Do not smoke: If you smoke, it is never too late to quit. Smoking increases your risk of heart disease. Ask your primary healthcare provider for information if you need help quitting.
You may develop heart disease if you do not follow a heart healthy diet. High blood cholesterol puts you at a higher risk for heart disease. Untreated high blood pressure may lead to a stroke. It can also lead to a heart attack or heart or kidney failure. Obesity is linked to medical problems, such as heart disease, high blood pressure, stroke, and diabetes. You may be more likely to have another stroke or heart attack if you do not follow this diet.
Contact your primary healthcare provider if:
You have questions or concerns about your condition or care.
Thursday, March 14, 2013
S-Atenolol is a selectiveBeta-1 Receptor Blocker and Antihypertensive
S-Atenolol selectively blocks the Beta-1 receptors and it significantly reduces both maximal and sub maximal exercise heat rates in a dose-related manner. Entocrine and metabolic actions of S-Atenolol include lowering of plasma rennin activity and free fatty acids.
HYPERTENSION: Adult: Stage 1 Hypertension 12.5-25mg O.D
Stage 2 Hypertension 5mg O.D
ANGINA: Adult: 12.5-25mg O.D
MYOCARDIAL INFARCTION: Adult: 12.5-25mg O.D
Migraine prophylaxis50-100 mg/day.
Contraindications Hypersensitivity, 2nd and 3rd degree heart block, cardiogenic shock, bronchospasm, history of obstructive airway disease, metabolic acidosis, hypotension, severe peripheral arterial disease, sinus bradycardia.
Special Precautions Renal failure, DM, children, pregnancy and lactation. May mask symptoms of hyperthyroidism and hypoglycaemia. Avoid abrupt withdrawal.
Adverse Drug Reactions Fatigue, cold extremities, bradycardia, heart failure, headache, dizziness, hallucinations, confusion and sleep disturbances.
Drug Interactions Disopyramide when given in combination with atenolol depresses myocardial contractility and may precipitate cardiac failure. Efficacy may be antagonised by NSAIDs.
Potentially Fatal: Concurrent use with verapamil may precipitate heart failure in patients with impaired left ventricular function. Simultaneous withdrawal of atenolol and clonidine may result in severe rebound hypertension.
Levamlodipine , also known as levoamlodipine or S-amlodipine is a pharmacologically active enantiomer of amlodipine. Amlodipine belongs to the dihydropyridine group of calcium channel blocker used as an antihypertensive and antianginal agent. Levamlodipine is currently marketed in India under the trade names Eslo (Zuventus Healthcare Ltd.), Asomex (Emcure Pharmaceutical Ltd), and Espin (Intas Pharmaceuticals Ltd.
(S)-3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate
Hypertension - Adult: 2.5 mg once daily.
Hepatic impairment: Dosage reduction may be required.
Should be taken on an empty stomach. Take on an empty stomach.
MECHANISM OF ACTION
Amlodipine blocks the transmembrane influx of calcium into the vascular and cardiac smooth muscles resulting in vasodilation and hence a fall in blood pressure. Levamlodipine is an allosteric modulator and acts on the L-type of calcium channels.Receptor binding studies have shown that out of the two forms only the (S)-enantiomer of amlodipine binds to and blocks L-type calcium channels whereas the (R)-enantiomer has no activity on these channels.
The precise mechanisms by which levamlodipine relieves angina have not been fully explored, but are thought to include the following:
Decreases peripheral resistance by arteriolar vasodilatation leading to the reduction in oxygen requirement and energy consumption of cardiac smooth muscles.
Decreases coronary vascular resistance and can lead to an increase in coronary blood flow.
Safety and tolerability
The use of racemic amlodipine is commonly associated with adverse events like peripheral edema and other side effects like headache, dizziness, flushing and abdominal pain. Controlled clinical trials showed that levamlodipine is rarely associated with these side effects. No controlled clinical study of levamlodipine has been performed in patients with hepatic impairment and renal impairment. Clinical studies in patients with normal liver function have shown that there is no elevation in the hepatic enzymes with the use of levamlodipine.However, caution should be taken while administering levamlodipine to such patients.
In a post-marketing surveillance study, levamlodipine (2.5/5 mg) was found to be well tolerated (n = 1859) in patients with hypertension. Out of 314 patients, who reported peripheral edema with conventional amlodipine were switched over to levamlodipine and edema was resolved in 310 patinets at the end of 4 weeks. Only in 4 patients, edema was sustained. Only 30 patients (out of 1859) reported side effects. These side effects included vertigo, tachycardia, cough, headache, fever, mild difficulty in breathing and edema. Adverse events were of mild in nature and no serious adverse events were reported.
Amlovas-SN (Levamlodipine and Nebivolol) - Macleods, India
Atenova-SA (Levamlodipine and Atenolol) - Lupin, India
Esam - Torrent, India
Esam-AT (Levamlodipine and Atenolol) - Torrent, India
Esam-LT (Levamlodipine and Losartan) - Torrent, India
Esam-R (Levamlodipine and Ramipril) - Torrent, India
Esamlovin - East West, India
Eslo - Zuventus, India
Eslo TAN (Levamlodipine and Losartan) - Zuventus, India
Eslo-AT (Levamlodipine and Atenolol) - Zuventus, India
Listril-SM (Levamlodipine and Lisinopril) - Torrent, India
Modlip-AM (Levamlodipine and Atorvastatin) - Torrent, India
Nebicard-SM (Levamlodipine and Nebivolol) - Torrent, India
Nebipril-SA (Levamlodipine and Nebivolol) - Alkem, India
Nebistar-SA (Levamlodipine and Nebivolol) - Lupin, India
Nubeta-SM (Levamlodipine and Nebivolol) - Abbott, India
Nusar-AM - Emcure, India
Q-Spin - Q-Check, India
Ramipro-A - Emcure, India
S-Amcard - Systopic, India -
S-Amlip - Cipla, India
S-Amlong - Micro Carsyon, India
S-Amlovas - Macleods, India
Shi Hui Da - Shihuida Group, China
S-Numlo - Emcure, India
Xinta - Simcere, China
3. AMILORIDE + HYDROCHLORTHIAIDE
5. AMLODIPINE + LISINOPRIL
7. ATENOLOL + AMLODIPINE
8. ATENOLOL + CHLORTHALIDONE
9. ATENOLOL + NIFIDIPINE
15. CAPTOPRIL + HYDROCHORTHIAIDE
20. CLONIDINE + HYDROCHLORTHIAIDE
24. ENALAPRIL + AMLODIPINE
25. ENALAPRIL + HYDROCHLORTHIAIDE
29. FRUSEMIDE + AMILORIDE
31. HYDROCHLORTHIAIDE + RAMIPRIL
38. LOSARTAN + RAMIPRIL
39. LOSARTAN POTASIUM
43. METOPROLOL + HYDROCHLORTHIAIDE
48. PERINDOPRIL + INDAPAMIDE
53. PROPRANOLOL + HYDROCHLORTHIAIDE
55. SODIUM NITROPRUSSIDE
60. OTHER ANTI HYPERTENSIVES/ COMBINATIONS
ANTI ANGINAL & VASODIALATORS
63. ERYTHRITYL TETRANITRATE
64. GLYCERYL TRINITRATE
65. ISOSORBIDE DINITRATE
67. ISOSORBIDE-5-MONONITRATE + ASPIRIN
77. MEXILETINE HCL
PEROPHERAL VASO DIALATORS
87. XANTHINOL NICOTINATE
ANTI COAGULANT, ANTITHROMBOTICS, FIBRINOLYTICS
103. NANDROPARIN CALCIUM
111. AMINOCAPROIC ACID
116. TRANEXAMIC ACID
IONOTROPIC AGENTS, DRUG USED IN CHF
LIPID LOVERING DRUGS
145. NICOTINIC ACID
OTHER CARDIO VASCULAR DRUGS
150. ATROPINE SULPHATE
151. CALCIUM DOBESILATE
152. DIOSMIN/FLAVONOIDS -
154. OTHER CARDIO VASCULAR COMBINATIONS
Tuesday, March 12, 2013
The circulatory system is an organ system that permits blood and lymph circulation to transport nutrients, oxygen, carbon dioxide, hormones, blood cells, etc. to and from cells in the body to nourish it and help to fight diseases, stabilize body temperature and pH, and to maintain homeostasis.
This system may be seen strictly as a blood distribution network, but some consider the circulatory system as composed of the cardiovascular system, which distributes blood, and the lymphatic system, which returns excess filtered blood plasma from the interstitial fluid as lymph. While humans, as well as other vertebrates, have a closed cardiovascular system , some invertebrate groups have an open cardiovascular system. The more primitive, diploblastic animal phyla lack circulatory systems. The lymphatic system, on the other hand, is an open system providing an accessory route for excess interstitial fluid to get returned to the blood.
Cardiovascular System Anatomy
The heart is a muscular pumping organ located medial to the lungs along the body’s midline in the thoracic region. The bottom tip of the heart, known as its apex, is turned to the left, so that about 2/3 of the heart is located on the body’s left side with the other 1/3 on right. The top of the heart, known as the heart’s base, connects to the great blood vessels of the body: the aorta, vena cava, pulmonary trunk, and pulmonary veins.
There are 2 primary circulatory loops in the human body: the pulmonary circulation loop and the systemic circulation loop.
Pulmonary circulation transports deoxygenated blood from the right side of the heart to the lungs, where the blood picks up oxygen and returns to the left side of the heart. The pumping chambers of the heart that support the pulmonary circulation loop are the right atrium and right ventricle.
Systemic circulation carries highly oxygenated blood from the left side of the heart to all of the tissues of the body (with the exception of the heart and lungs). Systemic circulation removes wastes from body tissues and returns deoxygenated blood to the right side of the heart. The left atrium and left ventricle of the heart are the pumping chambers for the systemic circulation loop.
Blood vessels are the body’s highways that allow blood to flow quickly and efficiently from the heart to every region of the body and back again. The size of blood vessels corresponds with the amount of blood that passes through the vessel. All blood vessels contain a hollow area called the lumen through which blood is able to flow. Around the lumen is the wall of the vessel, which may be thin in the case of capillaries or very thick in the case of arteries.
All blood vessels are lined with a thin layer of simple squamous epithelium known as the endothelium that keeps blood cells inside of the blood vessels and prevents clots from forming. The endothelium lines the entire circulatory system, all the way to the interior of the heart, where it is called the endocardium.
There are three major types of blood vessels: arteries, capillaries and veins. Blood vessels are often named after either the region of the body through which they carry blood or for nearby structures. For example, the brachiocephalic artery carries blood into the brachial (arm) and cephalic (head) regions. One of its branches, the subclavian artery, runs under the clavicle; hence the name subclavian. The subclavian artery runs into the axillary region where it becomes known as the axillary artery.
Arteries and Arterioles: Arteries are blood vessels that carry blood away from the heart. Blood carried by arteries is usually highly oxygenated, having just left the lungs on its way to the body’s tissues. The pulmonary trunk and arteries of the pulmonary circulation loop provide an exception to this rule – these arteries carry deoxygenated blood from the heart to the lungs to be oxygenated.
Arteries face high levels of blood pressure as they carry blood being pushed from the heart under great force. To withstand this pressure, the walls of the arteries are thicker, more elastic, and more muscular than those of other vessels. The largest arteries of the body contain a high percentage of elastic tissue that allows them to stretch and accommodate the pressure of the heart.
Smaller arteries are more muscular in the structure of their walls. The smooth muscles of the arterial walls of these smaller arteries contract or expand to regulate the flow of blood through their lumen. In this way, the body controls how much blood flows to different parts of the body under varying circumstances. The regulation of blood flow also affects blood pressure, as smaller arteries give blood less area to flow through and therefore increases the pressure of the blood on arterial walls.
Arterioles are narrower arteries that branch off from the ends of arteries and carry blood to capillaries. They face much lower blood pressures than arteries due to their greater number, decreased blood volume, and distance from the direct pressure of the heart. Thus arteriole walls are much thinner than those of arteries. Arterioles, like arteries, are able to use smooth muscle to control their aperture and regulate blood flow and blood pressure.
Capillaries: Capillaries are the smallest and thinnest of the blood vessels in the body and also the most common. They can be found running throughout almost every tissue of the body and border the edges of the body’s avascular tissues. Capillaries connect to arterioles on one end and venules on the other.
Capillaries carry blood very close to the cells of the tissues of the body in order to exchange gases, nutrients, and waste products. The walls of capillaries consist of only a thin layer of endothelium so that there is the minimum amount of structure possible between the blood and the tissues. The endothelium acts as a filter to keep blood cells inside of the vessels while allowing liquids, dissolved gases, and other chemicals to diffuse along their concentration gradients into or out of tissues.
Precapillary sphincters are bands of smooth muscle found at the arteriole ends of capillaries. These sphincters regulate blood flow into the capillaries. Since there is a limited supply of blood, and not all tissues have the same energy and oxygen requirements, the precapillary sphincters reduce blood flow to inactive tissues and allow free flow into active tissues.
Veins and Venules: Veins are the large return vessels of the body and act as the blood return counterparts of arteries. Because the arteries, arterioles, and capillaries absorb most of the force of the heart’s contractions, veins and venules are subjected to very low blood pressures. This lack of pressure allows the walls of veins to be much thinner, less elastic, and less muscular than the walls of arteries.
Veins rely on gravity, inertia, and the force of skeletal muscle contractions to help push blood back to the heart. To facilitate the movement of blood, some veins contain many one-way valves that prevent blood from flowing away from the heart. As skeletal muscles in the body contract, they squeeze nearby veins and push blood through valves closer to the heart.
When the muscle relaxes, the valve traps the blood until another contraction pushes the blood closer to the heart. Venules are similar to arterioles as they are small vessels that connect capillaries, but unlike arterioles, venules connect to veins instead of arteries. Venules pick up blood from many capillaries and deposit it into larger veins for transport back to the heart.
The heart has its own set of blood vessels that provide the myocardium with the oxygen and nutrients necessary to pump blood throughout the body. The left and right coronary arteries branch off from the aorta and provide blood to the left and right sides of the heart. The coronary sinus is a vein on the posterior side of the heart that returns deoxygenated blood from the myocardium to the vena cava.
Hepatic Portal Circulation
The veins of the stomach and intestines perform a unique function: instead of carrying blood directly back to the heart, they carry blood to the liver through the hepatic portal vein. Blood leaving the digestive organs is rich in nutrients and other chemicals absorbed from food. The liver removes toxins, stores sugars, and processes the products of digestion before they reach the other body tissues. Blood from the liver then returns to the heart through the inferior vena cava.
The average human body contains about 4 to 5 liters of blood. As a liquid connective tissue, it transports many substances through the body and helps to maintain homeostasis of nutrients, wastes, and gases. Blood is made up of red blood cells, white blood cells, platelets, and liquid plasma.
Red Blood Cells: Red blood cells, also known as erythrocytes, are by far the most common type of blood cell and make up about 45% of blood volume. Erythrocytes are produced inside of red bone marrow from stem cells at the astonishing rate of about 2 million cells every second. The shape of erythrocytes is biconcave—disks with a concave curve on both sides of the disk so that the center of an erythrocyte is its thinnest part. The unique shape of erythrocytes gives these cells a high surface area to volume ratio and allows them to fold to fit into thin capillaries. Immature erythrocytes have a nucleus that is ejected from the cell when it reaches maturity to provide it with its unique shape and flexibility. The lack of a nucleus means that red blood cells contain no DNA and are not able to repair themselves once damaged.
Erythrocytes transport oxygen in the blood through the red pigment hemoglobin. Hemoglobin contains iron and proteins joined to greatly increase the oxygen carrying capacity of erythrocytes. The high surface area to volume ratio of erythrocytes allows oxygen to be easily transferred into the cell in the lungs and out of the cell in the capillaries of the systemic tissues.
White Blood Cells: White blood cells, also known as leukocytes, make up a very small percentage of the total number of cells in the bloodstream, but have important functions in the body’s immune system. There are two major classes of white blood cells: granular leukocytes and agranular leukocytes.
Granular Leukocytes: The three types of granular leukocytes are neutrophils, eosinophils, and basophils. Each type of granular leukocyte is classified by the presence of chemical-filled vesicles in their cytoplasm that give them their function. Neutrophils contain digestive enzymes that neutralize bacteria that invade the body. Eosinophils contain digestive enzymes specialized for digesting viruses that have been bound to by antibodies in the blood. Basophils release histamine to intensify allergic reactions and help protect the body from parasites.
Agranular Leukocytes: The two major classes of agranular leukocytes are lymphocytes and monocytes. Lymphocytes include T cells and natural killer cells that fight off viral infections and B cells that produce antibodies against infections by pathogens. Monocytes develop into cells called macrophages that engulf and ingest pathogens and the dead cells from wounds or infections.
Platelets : Also known as thrombocytes, platelets are small cell fragments responsible for the clotting of blood and the formation of scabs. Platelets form in the red bone marrow from large megakaryocyte cells that periodically rupture and release thousands of pieces of membrane that become the platelets. Platelets do not contain a nucleus and only survive in the body for up to a week before macrophages capture and digest them.
Plasma: Plasma is the non-cellular or liquid portion of the blood that makes up about 55% of the blood’s volume. Plasma is a mixture of water, proteins, and dissolved substances. Around 90% of plasma is made of water, although the exact percentage varies depending upon the hydration levels of the individual. The proteins within plasma include antibodies and albumins. Antibodies are part of the immune system and bind to antigens on the surface of pathogens that infect the body. Albumins help maintain the body’s osmotic balance by providing an isotonic solution for the cells of the body. Many different substances can be found dissolved in the plasma, including glucose, oxygen, carbon dioxide, electrolytes, nutrients, and cellular waste products. The plasma functions as a transportation medium for these substances as they move throughout the body.
Cardiovascular System Physiology
Functions of the Cardiovascular System
The cardiovascular system has three major functions: transportation of materials, protection from pathogens, and regulation of the body’s homeostasis.
Transportation: The cardiovascular system transports blood to almost all of the body’s tissues. The blood delivers essential nutrients and oxygen and removes wastes and carbon dioxide to be processed or removed from the body. Hormones are transported throughout the body via the blood’s liquid plasma.
Protection: The cardiovascular system protects the body through its white blood cells. White blood cells clean up cellular debris and fight pathogens that have entered the body. Platelets and red blood cells form scabs to seal wounds and prevent pathogens from entering the body and liquids from leaking out. Blood also carries antibodies that provide specific immunity to pathogens that the body has previously been exposed to or has been vaccinated against.
Regulation: The cardiovascular system is instrumental in the body’s ability to maintain homeostatic control of several internal conditions. Blood vessels help maintain a stable body temperature by controlling the blood flow to the surface of the skin. Blood vessels near the skin’s surface open during times of overheating to allow hot blood to dump its heat into the body’s surroundings. In the case of hypothermia, these blood vessels constrict to keep blood flowing only to vital organs in the body’s core. Blood also helps balance the body’s pH due to the presence of bicarbonate ions, which act as a buffer solution. Finally, the albumins in blood plasma help to balance the osmotic concentration of the body’s cells by maintaining an isotonic environment.
The Circulatory Pump
The heart is a four-chambered “double pump,” where each side (left and right) operates as a separate pump. The left and right sides of the heart are separated by a muscular wall of tissue known as the septum of the heart. The right side of the heart receives deoxygenated blood from the systemic veins and pumps it to the lungs for oxygenation. The left side of the heart receives oxygenated blood from the lungs and pumps it through the systemic arteries to the tissues of the body. Each heartbeat results in the simultaneous pumping of both sides of the heart, making the heart a very efficient pump.
Regulation of Blood Pressure
Several functions of the cardiovascular system can control blood pressure. Certain hormones along with autonomic nerve signals from the brain affect the rate and strength of heart contractions. Greater contractile force and heart rate lead to an increase in blood pressure. Blood vessels can also affect blood pressure. Vasoconstriction decreases the diameter of an artery by contracting the smooth muscle in the arterial wall. The sympathetic (fight or flight) division of the autonomic nervous system causes vasoconstriction, which leads to increases in blood pressure and decreases in blood flow in the constricted region. Vasodilation is the expansion of an artery as the smooth muscle in the arterial wall relaxes after the fight-or-flight response wears off or under the effect of certain hormones or chemicals in the blood. The volume of blood in the body also affects blood pressure. A higher volume of blood in the body raises blood pressure by increasing the amount of blood pumped by each heartbeat. Thicker, more viscous blood from clotting disorders can also raise blood pressure.
Hemostasis, or the clotting of blood and formation of scabs, is managed by the platelets of the blood. Platelets normally remain inactive in the blood until they reach damaged tissue or leak out of the blood vessels through a wound. Once active, platelets change into a spiny ball shape and become very sticky in order to latch on to damaged tissues. Platelets next release chemical clotting factors and begin to produce the protein fibrin to act as structure for the blood clot. Platelets also begin sticking together to form a platelet plug. The platelet plug will serve as a temporary seal to keep blood in the vessel and foreign material out of the vessel until the cells of the blood vessel can repair the damage to the vessel wall.