Formulary
Terazosin: Indications, Dosing, Side Effects and Interactions
Terazosin clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 3 min read
Terazosin: Indications, Dosing, Side Effects and Interactions
Terazosin clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Mild to moderate hypertension**
- **Adult** (By Mouth): 1 mg daily for 7 days, then increased if necessary to 2 mg daily, dose should be taken at bedtime; maintenance 2-10 mg once daily, doses above 20 mg rarely improve efficacy.
**Benign prostatic hyperplasia**
- **Adult** (By Mouth): Initially 1 mg daily, dose should be taken at bedtime, if necessary dose may be doubled at intervals of 1-2 weeks according to response; maintenance 5-10 mg daily; maximum 10 mg per day.
Cautions
Cataract surgery (risk of intra-operative floppy iris syndrome); elderly; first dose Cautions, further information First dose First dose may cause collapse due to hypotension within 30-90 minutes, therefore should be taken on retiring to bed; may also occur with rapid dose increase. Elderly For alpha 1 -selective adrenoceptor blockers, Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria to aid medication reviews (see Prescribing in the elderly for information). Potentially inappropriate: in those with symptomatic postural hypotension or micturition syncope (risk of precipitating recurrent syncope) in those with persistent postural hypotension i.e. recurrent drop in systolic blood pressure 20 mmHg (risk of syncope and falls).
Contraindications
History of micturition syncope (in benign prostatic hyperplasia); history of postural hypotension (in benign prostatic hyperplasia)
Side effects
Frequency not known Angioedema; anxiety; arrhythmias; arthritis; asthenia; chest pain; conjunctivitis; constipation; cough; depression; diarrhoea; dizziness; drowsiness; dry mouth; dyspnoea; epistaxis; fever; flatulence; gastrointestinal discomfort; gout; headache; hyperhidrosis; increased risk of infection; insomnia; joint disorders; myalgia; nasal congestion; nausea; oedema; pain; palpitations; paraesthesia; postural hypotension; sexual dysfunction; skin reactions; syncope; thrombocytopenia; tinnitus; urinary disorders; vasodilation; vertigo; vision disorders; vomiting; weight increased
Interactions
**Severe interactions:**
- In two interaction studies with healthy normotensive volunteers after forced titration of the alpha-blockers tamsulosin or terazosin to high doses, hypotension (in some cases symptomatic) was...
**Other interactions (8):**
- Effects of dutasteride on the pharmacokinetics of other drugs In a small study (n = 24) of two weeks duration in healthy men, dutasteride (0.5 mg daily) had no effect on the pharmacokinetics of...
- In a small study (N=24) of two week's duration in healthy men, dutasteride (0.5 mg daily) had no effect on the pharmacokinetics of tamsulosin or terazosin.
- Among subjects treated with terazosin, hypotension was observed more frequently when vardenafil and terazosin were given simultaneously than when the dosing was separated by a time interval of 6...
- Based on the results of interaction studies conducted with vardenafil in patients with benign prostatic hyperplasia (BPH) on stable tamsulosin, terazosin or alfuzosin therapy: When vardenafil was...
- Hypotension was not observed when vardenafil 5 mg and terazosin administration was separated by 6 hours.
- Combinations to be taken into account Potential additive antihypertensive effect Concomitant medications which could potentiate the antihypertensive effect of nicardipine, with an increased risk of...
Pregnancy
No evidence of teratogenicity; manufacturers advise use only when potential benefit outweighs risk.
Breast feeding
No information available.
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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