Generic
Terazosin
8 brands available in the market
At a glance
Terazosin is an alpha-1 adrenergic blocker used for hypertension and benign prostatic hyperplasia (BPH). It lowers blood pressure by relaxing blood vessels and improves urine flow by relaxing prostate muscles.
Description
Terazosin is a selective alpha-1 adrenoceptor competitive blocker. It blocks postsynaptic receptors to decrease arterial tone and relaxes smooth muscle of the bladder neck, reducing bladder outlet obstruction. Long-term use induces prostate cell apoptosis by enhancing TGF-β1, p27kip1, and the caspase cascade.
Indications
- Hypertension
- Benign Prostatic Hyperplasia (BPH) symptoms
Therapeutic class
Alpha Adrenergic Blockers
Pharmacological class
Alpha-1 Adrenergic Blocker
Pharmacology
Terazosin blocks postsynaptic alpha-1 receptors, relaxing smooth muscle in blood vessels and the prostate, lowering blood pressure and improving urinary flow. Long-term use induces apoptosis of prostate cells via TGF-β1, p27kip1, and the caspase cascade.
Mechanism of action
Lowers blood pressure and improves urine flow by relaxing blood vessels and prostate muscles.
Dosage
Adult Dose (Oral):
- Hypertension/BPH: Start 1 mg at bedtime (max), increase gradually at 7-day intervals
- Hypertension maintenance: 2-10 mg/day; max 20 mg/day in 1-2 divided doses
- BPH maintenance: 5-10 mg/day
- Elderly: Start 0.5 mg at bedtime
Administration
- Take with or without food
- Swallow tablet whole; do not chew, crush, or break
- Take the first dose at bedtime (to avoid hypotension)
Missed dose
If you miss a dose, skip it and continue with your normal schedule; do not double the dose.
Side effects
Common Side Effects:
- Orthostatic hypotension (dizziness)
- Headache, drowsiness
- Low energy, weakness
- Palpitations, nausea
- Peripheral edema, priapism (rare)
Precautions & warnings
- First dose may cause hypotension (within 30-90 minutes); take at bedtime
- Caution with other antihypertensives (risk of significant hypotension)
- Inform ophthalmologist before cataract surgery (IFIS risk)
- May affect driving ability (dizziness, drowsiness)
Contraindications
- Hypersensitivity to quinazoline derivatives
Drug interactions
- PDE-5 inhibitors (sildenafil, tadalafil): Additive BP-lowering effects and symptomatic hypotension
- Other antihypertensives (verapamil): Significant hypotension
Food interactions
Alcohol is unsafe with Terazosin (excessive blood pressure reduction and dizziness).
Use in pregnancy
Use in Pregnancy: May be unsafe; animal studies show harmful effects; use only if clearly needed; consult your doctor.
Pregnancy Category: D — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably unsafe; limited data suggests drug may pass into breast milk and harm the baby; consult your doctor.
Pediatric use
Safety and efficacy not established in children
Geriatric use
Elderly: Start at 0.5 mg
Renal / hepatic impairment
Renal Impairment: Safe in kidney disease; no dose adjustment needed; consult your doctor.
Hepatic Impairment: Caution required; dose adjustment may be needed; do not use in severe liver disease; consult your doctor.
Overdose effects
Overdose may cause acute hypotension; lie patient down; plasma volume expansion and noradrenergic vasopressor may be needed; provide symptomatic treatment.
Storage conditions
Store below 30°C, away from light and moisture; keep out of reach of children.
Chemical structure
Terazosin