Terazosin Uses, Dosage, Side Effects & Benefits | DrugsAtlas
Authoritative Clinical Reference
DRUG NAME: Terazosin
Therapeutic Class: Alpha-adrenergic blocker
Subclass: Alpha-1 adrenergic receptor antagonist
Speciality: Urology
Schedule (India): Schedule H
Route(s): Oral
Formulations Available in India:
• Tablets: 1 mg, 2 mg, 5 mg, 10 mg
• Tablets: 1 mg, 2 mg, 5 mg, 10 mg
INDICATIONS + DOSING — FOR CLINICIAN USE ONLY
Primary Indications (Approved / Standard in India):
1. Benign Prostatic Hyperplasia (BPH) — Symptomatic Relief
| Parameter | Recommendation |
| Starting dose | 1 mg once daily at bedtime |
| Titration | Increase to 2 mg, then 5 mg, then 10 mg at intervals of 1–2 weeks based on symptom response and tolerability |
| Usual maintenance dose | 5–10 mg once daily |
| Maximum dose | 20 mg once daily |
Key Clinical Notes:
• Bedtime dosing minimises first-dose hypotensive effect
• Standing blood pressure monitoring advised during titration
• Provides symptomatic relief only — not disease-modifying
• Reduce dose or discontinue if significant postural symptoms occur
• Bedtime dosing minimises first-dose hypotensive effect
• Standing blood pressure monitoring advised during titration
• Provides symptomatic relief only — not disease-modifying
• Reduce dose or discontinue if significant postural symptoms occur
2. Hypertension (Adjunct Therapy)
| Parameter | Recommendation |
| Starting dose | 1 mg once daily at bedtime |
| Titration | Increase by 1–2 mg increments every 1–2 weeks based on blood pressure response |
| Usual maintenance dose | 5–10 mg once daily |
| Maximum dose | 20 mg once daily |
Key Clinical Notes:
• Not first-line antihypertensive per Indian guidelines
• Consider as adjunct therapy or in patients with coexisting BPH
• Monitor for orthostatic hypotension especially when added to existing antihypertensives
• Not first-line antihypertensive per Indian guidelines
• Consider as adjunct therapy or in patients with coexisting BPH
• Monitor for orthostatic hypotension especially when added to existing antihypertensives
Secondary Indications – Adults Only (Off-label):
| Indication | PTSD-associated Nightmares / Sleep Disturbance — OFF-LABEL |
| Dose | 1–5 mg once daily at bedtime |
| Duration | Chronic as needed |
| Specialist input | Required (Psychiatry) |
| Evidence basis | International RCTs; off-label use in treatment-resistant cases |
| Indication | Ureteric Stone Expulsion (Medical Expulsive Therapy) — OFF-LABEL |
| Dose | 2–5 mg once daily |
| Duration | 2–4 weeks or until stone passage |
| Specialist input | Urology guidance recommended |
| Evidence basis | RCTs supporting alpha-blocker facilitated stone passage |
PAEDIATRIC DOSING (Specialist Only)
Primary Indications (Approved / Standard in India):
No approved paediatric indications in India. Not recommended below 18 years due to limited safety and efficacy data.
Secondary Indications – Paediatric Doses (Off-label):
| Indication | Paediatric Hypertension — OFF-LABEL |
| Starting dose | 0.05 mg/kg/day once daily |
| Titration | Increase gradually based on blood pressure response |
| Maximum dose | 0.4 mg/kg/day or 20 mg/day (whichever is lower) |
| Specialist input | Required (Paediatric Nephrology/Cardiology) |
| Evidence basis | Limited case series; extrapolated from adult data |
Not recommended below 18 years except under specialist supervision.
Safety Monitoring:
• Regular blood pressure (supine and standing)
• Orthostatic vital signs assessment
• Monitor for dizziness, sedation, syncope
• Regular blood pressure (supine and standing)
• Orthostatic vital signs assessment
• Monitor for dizziness, sedation, syncope
RENAL ADJUSTMENT
| eGFR (mL/min/1.73m²) | Recommendation |
| ≥30 | No dose adjustment required |
| <30 (Severe impairment) | Use with caution; initiate at lowest dose (1 mg); titrate slowly with close blood pressure monitoring |
| Haemodialysis | Not significantly dialysed; no supplemental dose required |
HEPATIC ADJUSTMENT
| Child-Pugh Class | Recommendation |
| A (Mild) | Start at 1 mg; titrate cautiously with blood pressure monitoring |
| B (Moderate) | Use with caution; slower titration; monitor for enhanced hypotensive effect |
| C (Severe) | Avoid — insufficient pharmacokinetic data; risk of prolonged drug effect |
CONTRAINDICATIONS
• Known hypersensitivity to terazosin or any quinazoline derivative
• History of syncope attributable to alpha-blocker therapy
• Concurrent use with other alpha-adrenergic blockers (additive hypotension)
CAUTIONS
• Elderly patients — increased risk of falls and syncope
• First-dose phenomenon — marked hypotension possible; initiate at bedtime
• Orthostatic hypotension — particularly during initial dosing and titration
• Impaired renal or hepatic function
• Planned cataract surgery — risk of Intraoperative Floppy Iris Syndrome (IFIS); inform ophthalmologist
• Concurrent antihypertensive therapy — additive blood pressure lowering
• Does not reduce prostate size — provides symptomatic relief only; rule out prostate malignancy before initiating BPH therapy
PREGNANCY
| Parameter | Recommendation |
| Safety category | Limited human data; safety not established |
| Preferred alternatives | Methyldopa, labetalol, nifedipine for gestational hypertension |
| When to use | Avoid unless potential benefit justifies risk; specialist supervision required |
| Monitoring | Maternal blood pressure (supine and standing); fetal growth assessment |
LACTATION
| Parameter | Recommendation |
| Compatibility | Limited data; avoid if possible due to lack of safety information |
| Preferred alternatives | Nifedipine, labetalol for hypertensive nursing mothers |
| Drug levels in milk | Unknown; likely low based on pharmacokinetic profile |
| Infant monitoring | Sedation, poor feeding, hypotension (if exposure unavoidable) |
ELDERLY
• Starting dose: 0.5–1 mg once daily at bedtime
• Titration: Slow increments every 2 weeks; smaller dose increases (1 mg steps)
• Additional risks: Higher susceptibility to orthostatic hypotension, syncope, and falls
• Monitoring: Regular standing blood pressure checks; fall risk assessment
• Consider tamsulosin as alternative if tolerability is poor (more uroselective)
MAJOR DRUG INTERACTIONS
| Interacting Drug | Mechanism / Effect | Recommendation |
| PDE-5 inhibitors (sildenafil, tadalafil, vardenafil) | Additive vasodilation → severe hypotension | AVOID co-initiation; if both required, separate dosing by ≥4–6 hours; use lowest PDE-5 inhibitor dose |
| Other alpha-blockers (prazosin, doxazosin, tamsulosin) | Additive alpha-blockade → profound hypotension | AVOID combination |
| Strong CYP3A4 inhibitors (ketoconazole, itraconazole) | May increase terazosin exposure | Use with caution; monitor for hypotension |
MODERATE DRUG INTERACTIONS
| Interacting Drug | Effect | Management |
| Antihypertensives (beta-blockers, CCBs, diuretics, ACE inhibitors) | Enhanced blood pressure lowering | Monitor blood pressure; may need dose adjustment |
| Diuretics | Increased risk of orthostatic hypotension | Initiate terazosin at lower dose |
| NSAIDs | May attenuate antihypertensive effect via sodium retention | Monitor blood pressure |
| Alcohol | Additive CNS depression and hypotension | Counsel on moderation |
| Verapamil | Increased terazosin bioavailability | Monitor for enhanced effect |
COMMON ADVERSE EFFECTS
• Dizziness
• Postural hypotension
• Fatigue and asthenia
• Headache
• Nasal congestion
• Palpitations
• Peripheral oedema
• Somnolence
SERIOUS ADVERSE EFFECTS
• Syncope — especially first-dose; may require discontinuation
• Intraoperative Floppy Iris Syndrome (IFIS) — during cataract surgery
• Severe hypotension with falls — may necessitate hospitalisation in elderly
• Priapism (rare) — requires urgent urological intervention
• Angioedema (rare)
MONITORING REQUIREMENTS
| Phase | Parameters |
| Baseline | Blood pressure (supine and standing); heart rate; assess fall risk; symptom severity score (IPSS for BPH) |
| After initiation/dose change | Blood pressure 2–4 hours after first dose; standing blood pressure daily during titration; assess for dizziness/syncope |
| Long-term | Periodic blood pressure monitoring; fall risk reassessment in elderly; BPH symptom reassessment; PSA if indicated |
BRANDS AVAILABLE IN INDIA
• Hytrin (Abbott)
• Terazin (Cipla)
• Olyster (Sun Pharma)
• Terazopress (various manufacturers)
PRICE RANGE (INR)
• 1 mg tablet: ₹2–₹5 per tablet
• 2 mg tablet: ₹3–₹6 per tablet
• 5 mg tablet: ₹5–₹8 per tablet
• Not listed under NLEM 2022; not under NPPA price control
• Government procurement prices significantly lower
CLINICAL PEARLS
• Always initiate at bedtime with 1 mg dose to minimise first-dose hypotensive effect — counsel patients to rise slowly from bed
• Useful dual-benefit agent for elderly men with both BPH and mild hypertension
• Inform ophthalmologist before cataract surgery — IFIS risk persists even after drug discontinuation
• Rule out prostate malignancy with PSA and DRE before attributing LUTS to BPH
• Tamsulosin may be preferred in patients at high risk for hypotension (more uroselective profile)
• If therapy interrupted for several days, re-titrate from 1 mg to avoid hypotensive episodes
TAGS
terazosin; alpha-blocker; BPH; hypertension; orthostatic-hypotension; IFIS; urology; elderly-caution; Schedule-H; first-dose-effect
VERSION
RxIndia v0.1 — 28 Feb 2026
REFERENCES
• CDSCO product inserts
• Indian Pharmacopoeia / National Formulary of India
• Goodman & Gilman’s The Pharmacological Basis of Therapeutics
• API Textbook of Medicine
• Indian Urological Society Guidelines — BPH management
• ICMR Hypertension Guidelines (general antihypertensive principles)
• AIIMS Formulary
• International RCTs (for off-label indications — PTSD, ureteric stones)
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Clinical Responsibility
This platform is designed strictly for healthcare professionals. Data provided is synthesized from authoritative pharmacological sources and clinical registries. Do not use for consumer medical decisions. Always verify critical dosing and contraindications with official institutional protocols and peer-reviewed journals.
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