Terazosin

Administration

• Type: α-blocker
• Dosage Forms: CAP: 1 mg, 2 mg, 5 mg, 10 mg
• Routes of Administration: Oral
• Common Trade Names: Hytrin

Adult Dosing

Benign prostatic hyperplasia

• 1-10 mg PO qhs

Hypertension

• 1-10 mg PO qhs

Urolithiasis

• Off-label: 2-5 mg PO qhs

Pediatric Dosing

Safety/efficacy not established

Special Populations

• Pregnancy Rating: C. weigh risk/benefit during pregnancy; no human data available
• Lactation risk: Infant risk cannot be ruled out; weigh risk/benefit while breastfeeding

Renal Dosing

• Adult: No adjustment

Hepatic Dosing

• Adult: No adjustment

Contraindications

• Allergy to drug/class

Adverse Reactions

Serious

• Hypotension
• Syncope
• Priapism

Common

• Orthostatic hypotension
• Dizziness
• Headache
• Weakness
• Nausea
• Nasal Congestion

Pharmacology

• Half-life: 12-14 hrs
• Metabolism: CYP450
• Excretion: Feces (60%) and renal (40%)

Mechanism of Action

• α-1A antagonist → smooth muscle relaxation in bladder neck, prostate, urethra → increased urine flow rate (See Tamsulosin)
• Theoretically less specific for bladder a-1 receptors and thus has a higher risk for orthostatic hypotension
  • In a single-center European RCT, terazosin (vs tamsulosin) appears to be associated with a higher rate of symptomatic orthostatic hypotension
  • In a meta-analysis from a Chinese team, more subjects receiving terazosin (vs tamsulosin) experienced dizziness and hypotension

See Also

• Alpha blockers
• Tamsulosin