Products
Terazosin is commercially available in tablet form (Hytrin BPH) and has been approved in many countries since 1994. It is no longer registered for the treatment of high blood pressure in many countries (formerly Hytrin), but the indication still exists in other countries.
Structure and properties
Terazosin (C19H25N5O4, Mr = 387.4 g/mol) is a quinazoline derivative. It is present in drugs as terazosin hydrochloride, a white crystalline powder that is soluble in water.
Effects
Terazosin (ATC G04CA03) has sympatholytic and antihypertensive properties and has beneficial effects on symptoms of prostate enlargement. The effects are due to competitive antagonism at alpha1 receptors and the resulting vasodilatation.
Indications
For symptomatic treatment of micturition symptoms associated with benign prostatic enlargement. In some countries, terazosin is also approved for the treatment of high blood pressure (essential hypertension).
Dosage
According to the SmPC. Therapy is started cautiously with a starter pack. The maintenance dose is taken once daily in the morning, independent of meals, and always at the same time of day.
Contraindications
- Hypersensitivity
- Idiopathic orthostatic hypotension
For complete precautions, see the drug label.
Interactions
Antihypertensives, nitrates, vasodilators, and phosphodiesterase-5 inhibitors may cause increased blood pressure lowering.
Adverse effects
Terazosin may cause marked low blood pressure. Other common side effects include dizziness, lightheadedness, loss of consciousness, fatigue, edema, headache, pain in the extremities, nervousness, drowsiness, paresthesias, palpable heartbeats, rapid heartbeat, chest pain, visual disturbances, nausea, constipation, diarrhea, and vomiting.
