MINIPRESS- prazosin hydrochloride capsule

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

PRAZOSIN HYDROCHLORIDE (UNII: X0Z7454B90) (PRAZOSIN - UNII:XM03YJ541D)

Available from:

Pfizer Laboratories Div Pfizer Inc

INN (International Name):

PRAZOSIN HYDROCHLORIDE

Composition:

PRAZOSIN 1 mg

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

MINIPRESS is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes, including this drug. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program's Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanis

Product summary:

MINIPRESS® 1 mg White 431 0069-4310-71 250's MINIPRESS® 2 mg Pink and White 437 0069-4370-71 250's MINIPRESS® 5 mg Blue and White 438 0069-4380-71 250's

Authorization status:

New Drug Application

Summary of Product characteristics

MINIPRESS- PRAZOSIN HYDROCHLORIDE CAPSULE
PFIZER LABORATORIES DIV PFIZER INC
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MINIPRESS®
CAPSULES
(PRAZOSIN HYDROCHLORIDE)
_FOR ORAL USE_
DESCRIPTION
MINIPRESS® (prazosin hydrochloride), a quinazoline derivative, is the
first of a new
chemical class of antihypertensives. It is the hydrochloride salt of
1-(4-amino-6,7-
dimethoxy-2-quinazolinyl)-4-(2-furoyl) piperazine and its structural
formula is:
Molecular formula C
H
N O •HCl
It is a white, crystalline substance, slightly soluble in water and
isotonic saline, and has a
molecular weight of 419.87. Each 1 mg capsule of MINIPRESS for oral
use contains drug
equivalent to 1 mg free base.
Inert ingredients in the formulations are: hard gelatin capsules
(which may contain Blue
1, Red 3, Red 28, Red 40, and other inert ingredients); magnesium
stearate; sodium
lauryl sulfate; starch; sucrose.
CLINICAL PHARMACOLOGY
The exact mechanism of the hypotensive action of prazosin is unknown.
Prazosin
causes a decrease in total peripheral resistance and was originally
thought to have a
direct relaxant action on vascular smooth muscle. Recent animal
studies, however, have
suggested that the vasodilator effect of prazosin is also related to
blockade of
postsynaptic alpha-adrenoceptors. The results of dog forelimb
experiments
demonstrate that the peripheral vasodilator effect of prazosin is
confined mainly to the
level of the resistance vessels (arterioles). Unlike conventional
alpha-blockers, the
antihypertensive action of prazosin is usually not accompanied by a
reflex tachycardia.
Tolerance has not been observed to develop in long term therapy.
Hemodynamic studies have been carried out in man following acute
single dose
administration and during the course of long term maintenance therapy.
The results
confirm that the therapeutic effect is a fall in blood pressure
unaccompanied by a
19
21
5
4
clinically significant change in cardiac output, heart rate, renal
blood flow and glomerular
filtration rate. There is no measurable negative chronotropic effect.
In clinical s