Hypovase (Prazosin)

Prazosin acts on the alpha‑1 adrenergic pathway to lower vascular resistance and relax smooth muscle in the prostate.

• Hypertension: reduces systolic and diastolic blood pressure by vasodilation.
• Benign prostatic hyperplasia: eases urinary outflow by relaxing prostatic smooth muscle.
• Post‑traumatic stress disorder: alleviates nightmares and sleep disturbances by modulating central adrenergic activity.

• Prazosin selectively blocks alpha‑1 adrenergic receptors on vascular smooth muscle and the prostate. This antagonism prevents norepinephrine‑induced vasoconstriction, leading to vasodilation and decreased peripheral vascular resistance, while also relaxing prostatic smooth muscle to improve urinary flow.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Dizziness: feeling light‑headed, especially after standing.
• Headache: mild to moderate intensity.
• Fatigue: general tiredness or lack of energy.
• Nasal congestion: blocked or runny nose.
• Palpitations: awareness of heartbeat.
• Nausea: upset stomach or urge to vomit.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Syncope: sudden loss of consciousness.
• Priapism: prolonged, painful erection.
• Allergic reaction: rash, itching, swelling, or difficulty breathing.
• Liver injury: jaundice, dark urine, or elevated liver enzymes.

Before initiating therapy, consider the following safety measures.

• Blood pressure monitoring: check regularly to avoid excessive hypotension.
• Initiate low dose: start with the smallest effective dose and titrate gradually.
• Discontinue cautiously: avoid abrupt cessation to prevent rebound hypertension.
• Cardiac disease caution: use carefully in patients with heart failure or coronary artery disease.
• Hepatic impairment: dose adjustment may be required in severe liver dysfunction.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Prazosin may interact with other medicines, altering its effect or safety profile.

Major Interactions (Avoid)

• Concurrent antihypertensives (e.g., ACE inhibitors, ARBs): additive blood‑pressure lowering effect.
• Phosphodiesterase‑5 inhibitors (e.g., sildenafil): risk of profound hypotension.
• Clonidine withdrawal: may precipitate severe hypertension.

Moderate Interactions (Monitor Closely)

• Diuretics: may enhance orthostatic hypotension.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): can blunt antihypertensive response.
• CYP3A4 inhibitors (e.g., ketoconazole): may increase prazosin plasma levels.
• Alcohol: can intensify dizziness and hypotension.