Alphapress 1 mg

Description

Indications

Hypertension: Alphapress is prescribed for the management of all grades of essential (primary) and secondary hypertension, regardless of the underlying cause. It can be used as a standalone treatment or in combination with a diuretic and/or other antihypertensive medications for optimal patient response. Long-term oral administration does not impair renal blood flow or glomerular filtration rate, making Alphapress a safe option for hypertensive patients with compromised renal function.

Left Ventricular Failure: Alphapress is indicated for the treatment of left ventricular failure. It may be added to the treatment plan of patients who do not respond adequately or become refractory to conventional therapies involving diuretics, with or without cardiac glycosides.

Raynaud’s Phenomenon and Raynaud’s Disease: Alphapress is effective in treating Raynaud’s phenomenon and Raynaud’s disease, reducing the severity, frequency, and duration of episodes.

Benign Prostatic Hyperplasia (BPH): Alphapress serves as an adjunct therapy in managing urinary obstruction symptoms caused by benign prostatic hyperplasia. It is beneficial for patients awaiting prostatic surgery.

Take medication only as prescribed by a registered physician.

Pharmacology

Prazosin, the active component of Alphapress, works by selectively inhibiting postsynaptic alpha-1-adrenoreceptors in vascular smooth muscle, leading to decreased total peripheral vascular resistance. This action results in a reduction of blood pressure in both supine and standing positions, with a more pronounced effect on diastolic pressure. Unlike other antihypertensive medications, abrupt discontinuation of Prazosin does not cause a rebound increase in blood pressure.

In patients with congestive heart failure, Prazosin reduces left ventricular filling pressure, lowers cardiac impedance, and enhances cardiac output without inducing reflex tachycardia. It also improves symptoms in Raynaud’s disease by reducing vascular resistance. For BPH, Prazosin relaxes prostatic and urethral smooth muscles, improving urinary flow and reducing symptoms.

Dosage & Administration

Prazosin Tablet:

• Therapy should begin with a low starting dose to ensure tolerability. The dosage is adjusted based on individual patient response over time.
• Response is generally observed within 1 to 14 days, and treatment should continue at the optimal dose before further increments are considered.

Hypertension:

• The daily dose may be increased gradually until the desired effect is achieved or a maximum of 20 mg is reached. A diuretic or beta-blocker can be added to enhance efficacy.
• For patients not on antihypertensive therapy: Start with 0.5 mg at bedtime, followed by 0.5 mg twice or three times daily for 3-7 days. Increase to 1 mg twice or three times daily based on blood pressure response.
• For patients receiving diuretics with uncontrolled blood pressure: Reduce the diuretic to a maintenance level and introduce Prazosin at 0.5 mg at bedtime, then adjust gradually.
• For patients on other antihypertensives but with inadequate control: Reduce the dosage of the other agent and introduce Prazosin at 0.5 mg at bedtime, then titrate accordingly.

Left Ventricular Failure:

• Initial dose: 0.5 mg two to four times daily. Titration should be based on clinical response, with doses ranging from 4 mg to 20 mg daily.
• Suggested starting dose: 0.5 mg twice to four times daily, increasing to 4 mg in divided doses.

Raynaud’s Phenomenon and Disease:

• Starting dose: 0.5 mg twice daily for 3-7 days.
• Maintenance dose: 1-2 mg twice daily, with some patients requiring up to 2 mg three times daily.

Benign Prostatic Hyperplasia:

• Starting dose: 0.5 mg twice daily for 3-7 days, then adjust based on patient response.
• Usual maintenance dose: 2 mg twice daily. Total daily doses above 4 mg should be used cautiously.

Prazosin XR Tablet:

• Must be swallowed whole without biting or dividing.
• Initial dose: 2.5 mg once daily for hypertension. The 5 mg tablet is not for initial use.
• Maintenance dose: Adjust as needed, up to a maximum of 20 mg once daily.
• Patients switching from regular Prazosin tablets should be adjusted to the nearest higher equivalent daily dose.

Take medication only as prescribed by a registered physician.

Drug Interactions

Alphapress XR has been used without adverse interactions with the following medications:

• Cardiac glycosides: Digitalis, Digoxin
• Hypoglycemic agents: Insulin, Chlorpropamide, Phenformin, Tolazamide, Tolbutamide
• Tranquilizers & sedatives: Chlordiazepoxide, Diazepam, Phenobarbital
• Antiarrhythmics: Procainamide, Propranolol, Quinidine
• Analgesics & anti-inflammatory drugs: Aspirin, Indomethacin, Phenylbutazone, Propoxyphene

Contraindications

Alphapress is contraindicated in patients with a known allergy to quinazolines.

Side Effects

Common side effects include dizziness, headache, drowsiness, weakness, palpitations, and nausea. These effects usually diminish with continued use. Other possible adverse effects include:

• Gastrointestinal disturbances: Vomiting, diarrhea, constipation, abdominal discomfort
• Cardiovascular effects: Orthostatic hypotension, tachycardia, edema
• Neurological issues: Nervousness, vertigo, hallucinations, depression, paresthesia
• Dermatological reactions: Rash, pruritus, alopecia, lichen planus
• Other: Urinary frequency, impotence, priapism, blurred vision, tinnitus, nasal congestion, dry mouth, fever

Some side effects have been rare, and their exact relationship to the medication is uncertain.

Pregnancy & Lactation

While animal studies have not shown teratogenic effects, the safety of Prazosin during pregnancy has not been established. It should only be used if the potential benefits outweigh the risks. Prazosin is excreted in small amounts in breast milk, so caution is advised when administered to nursing mothers.

Precautions & Warnings

• Hypertension: Some patients may experience an abrupt drop in blood pressure with the initial dose. Starting with a low dose and gradually increasing it can prevent this effect.
• Left Ventricular Failure: Patients on aggressive diuretic therapy should start with lower doses to avoid excessive blood pressure reduction.
• Raynaud’s Disease: Blood pressure monitoring is necessary, especially for patients on concurrent hypotensive medications.
• Benign Prostatic Hyperplasia: Elderly patients require careful blood pressure monitoring when initiating therapy.

Use in Special Populations

• Children: Not recommended for patients under 12 years as safety data is insufficient.
• Left Ventricular Failure Due to Mechanical Obstruction: Not suitable for conditions such as aortic stenosis, mitral stenosis, pulmonary embolism, or restrictive pericardial disease.

Overdose Management

In cases of overdose, supportive care should focus on cardiovascular stabilization. Patients should be placed in a supine position, with volume expanders and vasopressors administered if necessary. Prazosin is not dialyzable due to its protein-binding properties.

Therapeutic Class

Alpha adrenoceptor blocking drugs.

Storage Conditions

Store below 30°C in a dry place away from light and moisture. Keep out of reach of children.