Thursday, August 22, 2013

PRAZOSIN

Prazosin  is a sympatholytic drug used to treat high blood pressure and anxiety, PTSD, and panic disorder. It is an alpha-adrenergic blocker that is specific for the alpha-1 receptors. These receptors are found on vascular smooth muscle, where they are responsible for the vasoconstrictive action of norepinephrine. They are also found throughout the central nervous system.
In addition to its alpha-blocking activity, prazosin is an antagonist of the MT3 receptor (which is not present in humans), with selectivity for this receptor over the MT1 and MT2 receptors.

Prazosin is orally active and has a minimal effect on cardiac function due to its alpha-1 receptor selectivity. However, when prazosin is initially started, heart rate and contractility go up in order to maintain the pre-treatment blood pressures because the body has reached homeostasis at its abnormally high blood pressure. The blood pressure lowering effect becomes apparent when prazosin is taken for longer periods of time. The heart rate and contractility go back down over time and blood pressure decreases.
The antihypertensive characteristics of prazosin make it a second-line choice for the treatment of high blood pressure.
Prazosin is also useful in treating urinary hesitancy associated with prostatic hyperplasia, blocking alpha-1 receptors, which control constriction of both the prostate and ureters. Although not a first line choice for either hypertension or prostatic hyperplasia, it is a choice for patients who present with both problems concomitantly
This medication has shown to be effective in treating severe nightmares in children and people with PTSD symptoms.[4] Veterans have also been treated successfully at Seattle's VA Puget Sound Health Care System (VAPSHCS) for sleep disturbance related to PTSD. Doses are lower for this purpose than for control of blood pressure.

2-[4-(2-furoyl)piperazin-1-yl]-6,7-dimethoxyquinazolin-4-amine

BRAND NAMES  -
Mizide
Cyber-cr           Raptakos
Czopress XL Tab    CMG Biotech
Minipress Xl       Pfiser
Minipress Xl ITS   Pfiser
Prazocip -1 tab    Cipla
 Prazocip XL       Cipla
Prazopress         Sun pharma
Prazopress XL      Sun
Prazopress 1       sun
Prazopress 2       sun
Prazopress XL 5    Sun


Do NOT use prazosin if:
you are allergic to any ingredient in prazosin
Contact your doctor or health care provider right away if any of these apply to you.

Before using prazosin:

Some medical conditions may interact with prazosin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

if you are pregnant, planning to become pregnant, or are breast-feeding
if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
if you have allergies to medicines, foods, or other substances
if you have chest pain, heart disease, narcolepsy, or kidney problems
if you will be having eye surgery
Some MEDICINES MAY INTERACT with prazosin. Tell your health care provider if you are taking any other medicines, especially any of the following:

Diuretics (eg, furosemide, hydrochlorothiazide) or verapamil because they may increase the risk of prazosin's side effects
Beta-blockers (eg, propranolol) or phosphodiesterase inhibitors (eg, sildenafil) because their actions and the risk of their side effects may be increased by prazosin
This may not be a complete list of all interactions that may occur. Ask your health care provider if prazosin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use prazosin:

Use prazosin as directed by your doctor. Check the label on the medicine for exact dosing instructions.

Take prazosin by mouth with or without food.
If you miss a dose of prazosin, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use prazosin.

Important safety information:

Prazosin may cause dizziness, lightheadedness, or fainting after the first dose. Take the first dose at bedtime. If you get up during the night, sit up and stand slowly. Continue to sit up and stand slowly while you are taking prazosin.
Prazosin may cause dizziness, drowsiness, lightheadedness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use prazosin with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
Prazosin may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
Avoid engaging in any hazardous tasks for at least 24 hours after taking the first dose, missing several doses, increasing the dose, or taking other high blood pressure medications.
Before drinking alcohol, discuss it with your doctor.
Tell your doctor or dentist that you take prazosin before you receive any medical or dental care, emergency care, or surgery.
Patients who take medicine for high blood pressure often feel tired or run down for a few weeks after starting treatment. Be sure to take your medicine even if you may not feel "normal." Tell your doctor if you develop any new symptoms.
Prazosin may interfere with certain lab tests, including tests for pheochromocytoma (an adrenal gland tumor). Be sure your doctor and lab personnel know you are taking prazosin.
Use prazosin with extreme caution in the ELDERLY; they may be more sensitive to its effects.
Prazosin should not be used in CHILDREN; safety and effectiveness in children have not been confirmed.
PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using prazosin while you are pregnant. Prazosin is found in breast milk. If you are or will be breast-feeding while you use prazosin, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of prazosin:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Dizziness; drowsiness; dry mouth; frequent urination; headache; lack of energy; lightheadedness; nasal congestion; nausea; weakness.

Seek medical attention right away if any of these SEVERE side effects occur:
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; fainting; fast or irregular heartbeat; depression; severe or persistent dizziness; swelling of the hands or feet.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.


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