One catch per day.

High blood pressure

The effective mean dose is 5 mg / day.
Begin treatment with 2.5 mg / day.

This dosage may be sufficient and may be increased for some patients (especially the elderly), up to 5 mg / day and in some cases 10 mg / day.

Do not exceed 20 mg / day.

Pediatric population: In the absence of data on efficacy and safety of use, the use of prazosin is not recommended in children and adolescents.

Important: tablets will be swallowed whole. They are neither broken nor crushed or chewed.

Alpha-1 blocker vasodilator, prazosin is a chemical derivative of quinazoline, the first product of a new family of antihypertensive drugs.
Prazosin is an antihypertensive by reducing total resistances, but its mechanism of action is not yet fully known.

Pharmacology studies indicate that the vasodilator effect of prazosin is mainly related to blockade of post-synaptic alpha-1 receptors.
Hemodynamic studies have been performed in humans, hypertensive, after single administration or during long-term treatment. The results of these studies confirm that the usual therapeutic effect is a decrease in blood pressure without modification, clinically significant cardiac output, renal blood flow and glomerular filtration rate Renal blood flow and rate Are not modified during a long-term administration of prazosin: prazosin can therefore be used in patients with renal insufficiency

Contrary to what is observed, with other vasodilators, the activity of prazosin is not accompanied by reflex tachycardia.

Most studies show that long-term treatment has little effect on plasma renin activity

The abrupt interruption of treatment does not cause a rebound in blood pressure

By its vasodilatory action, prazosin increases the perfusion of the tissues affected by Raynaud's phenomena, improves the signs and symptoms and reduces the number and duration of paroxysmal access.

Some clinical studies show that prazosin decreases LDL + VLDL cholesterol levels and does not alter or increase HDL cholesterol levels. Therefore, prazosin is likely to have a favorable effect on the atherogenic ratio C.HDL / (C.LDL + C.VLDL).
Prazosin is contraindicated in patients with known hypersensitivity to quinazolines.


In order to achieve full antihypertensive effect, the prolonged-release prazosin tablet requires a normal gastrointestinal transit time In the case of shortened transit time, the pharmacokinetic and pharmacodynamic profile may be altered, decreasing Effectiveness, antihypertensive.

Orthostatic hypotension with varying degrees of severity may occasionally occur. Special attention will be paid to patients with dizziness or discomfort.
· The antihypertensive effect of prazosin may be increased by the combination with a diuretic, vasodilator or other antihypertensive drug (see Interactions with other medicinal products and other forms of interaction) Code>
Concomitant use of inhibitors, 5-phosphodiesterase (eg sildenafil, tadalafil, vardenafil) and ALPRESS L.P. 5 mg, tablet, sustained-release osmotic may lead to symptomatic hypotension in some patients. In order to minimize the risk of developing hypotension, orthostatic, the patient should be stabilized by the alpha-blocker treatment before starting administration of 5-phosphodiesterase inhibitors.

Perioperative flaccid iris syndrome (SIFP, a variant of the narrow pupil syndrome) has been observed during surgical cataract surgery in some patients treated or previously treated with tamsulosin. Isolated cases have also been reported with other α-1 blockers and the possibility of a class effect can not be ruled out. Since SIFP may cause additional technical difficulties during the operation of cataract, prior or present administration of α-1 blockers should be reported to the ophthalmologist prior to surgery.

Digestive pathology

A marked reduction in the digestive retention time of ALPRESS may influence the pharmacokinetic profile and hence the clinical efficacy of the drug. As with any form of osmotic tablet, caution is recommended in patients with severe gastrointestinal stenosis (pathological or iatrogenic). Rare cases of obstructive syndrome have been reported in patients with known stenosis as a result of the ingestion of another active ingredient in the same form.

Patient information

The patient should be informed that the tablets should be swallowed whole. The patient should not chew, cut, or crush the tablets. The patient should not worry if he sometimes notices in his stool some thing that resembles a tablet, the drug is contained in a non-absorbable matrix, specially designed to slowly release the active ingredient so as to allow Its absorption by the organism. The exhausted matrix is ​​then eliminated.

Precautions for use

This medication contains sodium, which contains 29.13 mg per tablet. A, take into account in patients on a diet strictly hyposodé.

Associations to be taken into account

· In case of use of general anesthetics, take into account an increase in the effects on blood pressure.

Similarly, in case of association with imipraminic antidepressants or neuroleptics, take into account the risk of hypotension, orthostatic specific to these products plus antihypertensive addition

Associations subject to precautions for use

· An additive effect is possible, in combination with another antihypertensive agent, in particular a calcium channel blocker

No drug interactions have been reported in clinical studies to date with the following medications

· Digitalis (digitalis and digoxin)

· Hypoglycaemic agents (insulin, chlorpromamide, tolbutamide)

· Tranquillizing and sedative (chlordiazepoxide, diazepam, phenobarbital)

· Anti-drip agents (allopurinol, colchicine, probenecid)

· Antiarrhythmic drugs (procainamide, propanolol, quinidine)

· Analgesics, antipyretics, anti-inflammatories.

+ 5-phosphodiesterase inhibitors (eg sildenafil, tadalafil, vardenafil), (see section 4.4) Warning and precautions for use
Concomitant use of inhibitors, 5-phosphodiesterase (eg sildenafil, tadalafil, vardenafil) and ALPRESS LP 5 mg, tablet, sustained-release osmotic may cause symptomatic hypotension in some patients (see section Custody and precautions) ".

Interaction with biochemical tests

False positive results may occur in pheochromocytoma screening tests (vanilmandelic acid: VMA and Methoxydroxyphenylglycol: MHPG) in patients treated with prazosin.
The following undesirable effects can occur and must do, subject to careful monitoring

- General disorders and administration site abnormalities, asthenia, malaise, sweating

- Cardiac disorders, orthostatic hypotension, exceptionally accompanied by loss of consciousness, angina pectoris, hypotension, syncope, bradycardia, tachycardia, edema of the limbs, redness of the face Br>
- Skin and subcutaneous tissue disorders: allergic reactions, skin rash such as pruritus, urticaria

- disorders of the nervous system: vertigo, headache, tinnitus, drowsiness, insomnia, visual disturbances, paresthesia, aggravation of a preexisting narcolepsy (Gélineau disease) associated with treatment with prazosin has been described in the literature < Code>
Gastrointestinal disorders: nausea, vomiting, constipation, diarrhea, epigastralgia, mouth, dry

- Disorders of the ENT and ophthalmic sphere: nasal or ocular congestion, epistaxis

Renal and urinary disorders: priapism, pollakiuria, urinary incontinence

- Breast and reproductive organs: impotence, gynecomastia

- Musculoskeletal and connective tissue disorders: arthralgia

Investigations, Positive Antibody Reaction, Antinuclear