Thursday, February 14, 2013

RANITIDINE

                     
rantac, zinetac,ranitin
3d Ranitidine
Ranitidine  is a histamine H2-receptor antagonist that inhibits stomach acid production. It is commonly used in treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). Ranitidine is also used alongside fexofenadine and other antihistamines for the treatment of skin conditions such as hives. Ranitidine is also known to give false positives for methamphetamine on drug tests.

 N-(2-[(5-[(dimethylamino)methyl]furan-2-yl)methylthio]ethyl)-N-methyl-2-nitroethene-1,1-diamine



Medical use

Certain preparations of ranitidine are available over the counter (OTC) in various countries. In the United States, 75-mg and 150-mg tablets are available OTC. Zantac OTC is manufactured by Boehringer Ingelheim. In Australia, packs containing seven or 14 doses of the 150-mg tablet are available in supermarkets, small packs of 150-mg and 300-mg tablets are schedule 2 pharmacy medicines. Larger doses and pack sizes still require a prescription.
Outside the United States and Canada, ranitidine is combined with bismuth (which acts as a mild antibiotic) as a citrate salt (ranitidine bismuth citrate, Tritec), to treat Helicobacter pylori infections. This combination is usually given with clarithromycin, an antibiotic.
Ranitidine can also be coadministered with NSAIDs to reduce the risk of ulceration. Proton-pump inhibitors (PPIs) are more effective for the prevention of NSAID-induced ulcers.
Ranitidine can be administered preoperatively to reduce the risk of aspiration pneumonia. The drug not only increases gastric pH, but also reduces the total output of gastric juice. Ranitidine may have an antiemetic effect when administered preoperatively.
It can be administered intravenously in intensive care units to critically ill patients (particularly geriatric ones) to reduce the risk of gastric bleeding.
The usual dose of ranitidine is either 150 mg twice a day or 300 mg once every 24 hours, usually at night. For ulcer treatment, a 300-mg night-time dose is especially important - as the increase in gastric/duodenal pH promotes healing overnight when the stomach and duodenum are empty. Conversely, for treating reflux, smaller and more frequent doses are more effective.
Ranitidine used to be administered long term for reflux treatment, sometimes indefinitely. However, PPIs have taken over this role.
In some patients with severe reflux, up to 600 mg of ranitidine can be administered daily, usually in four lots of 150 mg. Such a high dose was not unusual in the past, but nowadays a once-a-day PPI is used instead - both for convenience and because they are more effective in raising gastric pH. Patients with Zollinger-Ellison syndrome have been given doses of 6000 mg per day without any harm.


Adverse effects

Ranitidine appears to decrease mucosal perfusion in patients with acute renal or cardiac failure, and increases their risk of death.All drugs in its class decrease gastric intrinsic factor secretion, which can significantly reduce absorption of protein-bound vitamin B12 in humans.Elderly patients taking H2 receptor antagonists are more likely to require B12 supplementation than those not taking such drugs. H2 blockers may also reduce the absorption of drugs (azole antifungals, calcium carbonate) that require an acidic stomach.By suppressing acid-mediated breakdown of proteins, antacid preparations such as ranitidine may lead to an elevated risk of developing food or drug allergies, due to undigested proteins then passing into the gastrointestinal tract, where sensitisation occurs. Whether this risk occurs with only long-term use or with short-term use, as well, is unclear.
Ranitidine and other histamine H2 receptor antagonists may increase the risk of pneumonia in hospitalized patients. They may also increase the risk of community-acquired pneumonia in adults and children.Multiple studies suggest the use of H2 receptor antagonists such as raniditine may increase the risk of infectious diarrhoea, including traveller's diarrhoea and salmonellosis.
H2 antagonists may increase the risk of developing food allergies. Patients who take these agents develop higher levels of IgE against food, whether they had prior antibodies or not.Even months after discontinuation, an elevated level of IgE in 6% of patients was still found in this study.
Additionally, thrombocytopenia is a rare but known side effect. Drug-induced thrombocytopenia usually takes weeks or months to appear, but may appear within 12 hours of drug intake in a sensitized individual. Typically, the platelet count falls to 80% of normal, and thrombocytopenia may be associated with neutropenia and anemia.



About your treatment
Your doctor has ordered ranitidine hydrochloride to decrease the acid produced by your stomach.

Ranitidine may be added to an intravenous fluid that will drip through a needle or catheter placed in your vein for 15-20 minutes, one to four times a day. It also may be added to your total parenteral nutrition (TPN) solution.
Ranitidine decreases acid in your stomach to help treat an ulcer or prevent one from developing. Ranitidine helps to decrease the stomach pain, diarrhea, and loss of appetite that ulcers can cause. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Your health care provider (doctor, nurse, or pharmacist) may measure the effectiveness and side effects of your treatment using laboratory tests and physical examinations. It is important to keep all appointments with your doctor and the laboratory. The length of treatment depends on how you respond to the medication.

Precautions
Before administering ranitidine,
tell your doctor and pharmacist if you are allergic to ranitidine or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially acetaminophen (Tylenol), anticoagulants ('blood thinners') such as warfarin (Coumadin), propantheline, and vitamins.
tell your doctor if you have or have ever had kidney or liver disease or acute porphyria.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking ranitidine, call your doctor.

Administering your medication
Before you administer ranitidine, look at the solution closely. It should be clear and free of floating material. Gently squeeze the bag or observe the solution container to make sure there are no leaks. Do not use the solution if it is discolored, if it contains particles, or if the bag or container leaks. Use a new solution, but show the damaged one to your health care provider.

It is important that you use your medication exactly as directed. Do not change your dosing schedule without talking to your health care provider. Your health care provider may tell you to stop your infusion if you have a mechanical problem (such as a blockage in the tubing, needle, or catheter); if you have to stop an infusion, call your health care provider immediately so your therapy can continue.


Side effects
Ranitidine may cause side effects. Tell your health care provider if any of these symptoms are severe or do not go away:
Headache,   dizziness,   constipation,  diarrhea,  stomach pain,    upset stomach,

Storing your medication
Your health care provider probably will give you a several-day supply of ranitidine at a time. If you are receiving ranitidine intravenously (in your vein), you probably will be told to store it in the refrigerator or freezer.
Take your next dose from the refrigerator 1 hour before using it; place it in a clean, dry area to allow it to warm to room temperature.
If you are told to store additional ranitidine in the freezer, always move a 24-hour supply to the refrigerator for the next day's use.
Do not refreeze medications.
If you are receiving ranitidine mixed with TPN, you may be directed to keep it in a clean, dry area away from heat.

Store your medication only as directed. Make sure you understand what you need to store your medication properly.

Keep your supplies in a clean, dry place when you are not using them, and keep all medications and supplies out of reach of children. Your health care provider will tell you how to throw away used needles, syringes, tubing, and containers to avoid accidental injury.


In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Signs of infection
If you are receiving ranitidine in your vein or under your skin, you need to know the symptoms of a catheter-related infection (an infection where the needle enters your vein or skin). If you experience any of these effects near your intravenous catheter, tell your health care provider as soon as possible:
Tenderness,   warmth,    irritation,    drainage,      redness,  swelling,    pain
BRANDS – ZINETAC,RANTAC,RANITIN

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