Class: α1-Adrenergic Blocker
Dosage Forms. Capsule: 1 mg, 2 mg, 5 mg, 10 mg
Common FDA Label Indication, Dosing, and Titration.
1. Benign prostatic hyperplasia: 1 mg po daily hs, may titrate to 20 mg/d
2. Hypertension: 1 mg po daily hs, may titrate to 20-40 mg/d
1. Chronic prostatitis, chronic pelvic pain syndrome: 1 mg po daily for 4 d, 2 mg po daily for 10 d, then 5 mg po daily
MOA. Terazosin selectively blocks postsynaptic α1-adrenergic receptors. Total peripheral resistance is reduced through arterial and venous dilatations. Reflex tachycardia that occurs with other vasodilators is infrequent because there is no presynaptic α2-receptor blockade. Increases urine flow in BPH by relaxing smooth muscle tone in the bladder neck and prostate.
Drug Characteristics: Terazosin
Medication Safety Issues: Terazosin
Drug Interactions: Terazosin
Adverse Reactions: Terazosin
Efficacy Monitoring Parameters. Decreased BP, improvement in obstructive urinary symptoms.
Toxicity Monitoring Parameters. Sign/symptoms of hypotension, increased heart rate, LFTs.
Key Patient Counseling Points. Avoid activities requiring mental alertness or coordination until drug effects are realized, as drug may cause dizziness and somnolence. Rise slowly from a sitting/lying position, as this drug may cause orthostatic hypotension. May experience syncope or loss of consciousness with first dose. Take drug at bedtime to minimize side effects, especially the first dose. Avoid sudden discontinuation of drug, as this may cause rebound hypertension. Avoid alcohol while taking this drug.
Clinical Pearls. Safety and effectiveness not established in children.