Terazosin

Indications

Terazosin is used for: Hypertension, Benign prostatic hyperplasia

Adult Dose

Oral Hypertension Adult: Initially, 1 mg at bedtime, gradually increased at 7-day intervals according to response. Maintenance: 2-10 mg once daily. Max: 20 mg/day in 1 or 2 divided doses. Elderly: Initial: 0.5 mg at bed time and titrate to response Benign prostatic hyperplasia Adult: Initially, 1 mg at bedtime gradually increased at 7-day intervals according to response. Maintenance: 5-10 mg once daily. Hepatic impairment: Use with caution

Child Dose

Renal Dose

Administration

May be taken with or without food. Give first dose and subsequent increases at bedtime to avoid syncope

Contra Indications

Hypersensitivity to quinazoline derivatives.

Precautions

Prostate cancer should be ruled out before starting therapy. Patient w/ history of micturition syncope, prostate cancer, angina. Elderly. Pregnancy and lactation. Patient Counselling May impair ability to drive, operate machinery or engage in hazardous activities. Monitoring Parameters Monitor BP regularly. Lactation: Not known if excreted into breast milk; use caution

Pregnancy-Lactation

Pregnancy category: C Lactation: Not known if excreted into breast milk; use caution

Interactions

Concomitant admin w/ phosphodiesterase-5 (PDE-5) inhibitors (e.g. sildenafil) can result in additive BP lowering effects and symptomatic hypotension. Possible significant hypotension when admin w/ other antihypertensive agents e.g. verapamil.

Adverse Effects

Side effects of Terazosin : >10% Dizziness (10-20%), Asthenia (2-13%) 1-10% Hypotension (3-7%), Rhinitis/nasal congestion (2-6%), Lightheadedness (3-5%), Somnolence (3-5%), Palpitation (4%), Nausea (2-4%), Edema (3%), Sinusitis (3%), Dyspnea (2-3%), Fatigue (2.5%), Headache (2.5%), Back pain (2.4%), Flulike syndrome (2.4%), Tachycardia (2%), Amblyopia (1-2%), Blurred vision (1-2%), Impotence (1-2%), Syncope (1%)

Mechanism of Action

Terazosin is an alpha1-adrenoceptor antagonist which blocks peripheral postsynaptic receptors resulting to decreased arterial tone. It relaxes smooth muscle of the bladder neck causing a reduction of bladder outlet obstruction.