terazosin monohydrochloride dihydrate: clinical use

Prescribing considerations

• Exclude alternative causes of urinary symptoms, upper urinary tract obstruction and infection before treating presumed BPH.
• Marked postural hypotension or syncope may occur during initiation, reintroduction or treatment changes.
• Review concurrent antihypertensives and PDE-5 inhibitors for additive hypotension.
• Use particular caution in hepatic impairment; the selected product is not recommended in severe hepatic impairment.
• Ask about current or previous alpha-blocker use before cataract surgery because of possible intraoperative floppy iris syndrome.
• Use cautiously in specified low-filling-pressure cardiac failure, valvular stenosis and severe coronary disease.

Contraindications and cautions

• Hypersensitivity to terazosin or an excipient
• Known sensitivity to another alpha-adrenoceptor blocker
• History of micturition syncope

Monitoring

• Blood pressure and postural symptoms during initiation, reintroduction and relevant medicine changes
• Falls, dizziness or syncope risk, particularly in older adults
• Urinary symptoms and evidence of retention, infection, stones or upper tract obstruction
• Clinical response and adverse effects

Clinical pharmacology

Terazosin is a competitive postsynaptic alpha-1 adrenoceptor antagonist. It is well absorbed, highly protein-bound, extensively metabolised and eliminated through urine and faeces; food has little effect on bioavailability.

Formulation and product differences

• The selected product is an oral immediate-release tablet.
• It contains lactose and iron oxide E172 and is tan, round and flat-bevelled.
• Starter presentations use different tablet strengths and colours, so patients should follow the labelled pack sequence rather than colour alone.

Tablet

Route: Oral

Strengths: 2 mg, 5 mg, 10 mg