Terazosin
Pronunciation: (ter-AY-zoe-sin).
- Generic name
- Terazosin
- Brand names
- Terazosin Accord, Terazosin Teva, Terazosin Sandoz, Hytrin, Terazosin Apotex, Terazosin
- Drug class
- Alpha-1 adrenergic blocker (antihypertensive, urologic agent)
Availability and supply rules vary by country
Trade names by country: United States
Australia: · Full directory
What Terazosin is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Terazosin works
Terazosin selectively blocks postsynaptic alpha-1 adrenergic receptors in vascular smooth muscle and the prostate. This blockade leads to vasodilation, decreased peripheral vascular resistance, and relaxation of smooth muscle in the bladder neck and prostate, improving urine flow in BPH and lowering blood pressure. (2)
What Terazosin is used for
Hypertension
Hypertension (2)
Benign Prostatic Hyperplasia (BPH)
Benign Prostatic Hyperplasia (BPH) (2)
Urinary retention associated with BPH
Urinary retention associated with BPH (2)
Before taking Terazosin
Do not take / not appropriate for
- Contraindicated in patients with hypersensitivity to terazosin or other quinazoline derivatives. (Contraindication) (2)
Tell your clinician about
(2)How to take Terazosin
- General Instructions: Take Terazosin exactly as prescribed by your doctor, usually once daily at bedtime to minimize the risk of dizziness or fainting.. Adult Dosing: For hypertension or BPH, the usual starting dose is 1 mg at bedtime. The dose may be gradually increased by your doctor to a maintenance dose of 5–10 mg once daily, depending on your response.. Pediatric Dosing: Safety and efficacy in children have not been established; Terazosin is not recommended for pediatric use.. Administration: Swallow the tablet whole with a glass of water. Take at the same time each day, preferably at bedtime.. When To Stop: Do not stop taking Terazosin suddenly without consulting your doctor, as this may worsen your condition.. Storage: Store at room temperature (20–25°C/68–77°F), away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose—do not take two doses at once. If you miss several days of therapy, contact your doctor before restarting, as you may need to restart at a lower dose.
Overdose
Symptoms of overdose may include severe low blood pressure, dizziness, or fainting. Seek emergency medical attention or call your local poison control center immediately. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Dizziness
Incidence: Reported in the clinician-authored database; frequency not established
Orthostatic hypotension
Incidence: Reported in the clinician-authored database; frequency not established
Headache
Incidence: Reported in the clinician-authored database; frequency not established
Palpitations
Incidence: Reported in the clinician-authored database; frequency not established
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Fatigue
Incidence: Reported in the clinician-authored database; frequency not established
Syncope
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
May cause significant low blood pressure, especially after the first dose or dose increases — serious
Symptoms: May cause significant low blood pressure, especially after the first dose or dose increases. Risk of fainting (syncope) is highest with the first dose or when resuming therapy after a break. Use caution in patients with liver impairment. May cause priapism (prolonged, painful erection), which requires immediate medical attention. Inform your eye surgeon if you are taking or have taken Terazosin before cataract surgery.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindicated in patients with hypersensitivity to terazosin or other quinazoline derivatives. Use caution in patients with a history of orthostatic hypotension, hepatic impairment, or those undergoing cataract surgery (risk of Intraoperative Floppy Iris Syndrome).
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Terazosin may interact with other blood pressure medications, phosphodiesterase-5 inhibitors (such as sildenafil), and drugs that cause low blood pressure. Use caution when combining with other antihypertensives or medications that cause dizziness. Always inform your healthcare provider about all medicines and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA label reviewed for this page does not assign a current formal pregnancy category; animal reproduction studies have not shown fetal harm at clinically relevant exposures, but there are no adequate, well-controlled studies in pregnant women. Terazosin has no approved indication relevant to pregnancy (it is used for hypertension and BPH); any use during pregnancy should be directed by the treating physician, weighing benefit against unknown risk. (2)
Breastfeeding
The FDA label reviewed for this page states it is not known whether terazosin is excreted in human milk; because many drugs are excreted in human milk, caution is advised if terazosin is used by a breastfeeding parent. (2)
Children
Frequency: Not applicable. Weight Based: Not recommended for pediatric use. Max Daily Dose: Not applicable. Max Single Dose: Not applicable. Age Restrictions: Safety not established in children (2)
Renal_impairment
Per the FDA label reviewed for this page: clinically important changes in terazosin pharmacokinetics have not been observed in patients with impaired renal function, and dosage modification is generally not necessary; supplemental doses after hemodialysis are not needed. The effects of hepatic impairment on terazosin pharmacokinetics have not been specifically studied; because terazosin is extensively metabolized by the liver, the label advises starting at the lowest initial dose (1 mg at bedtime) and titrating cautiously in patients with hepatic impairment. (2)
Hepatic_impairment
Per the FDA label reviewed for this page: clinically important changes in terazosin pharmacokinetics have not been observed in patients with impaired renal function, and dosage modification is generally not necessary; supplemental doses after hemodialysis are not needed. The effects of hepatic impairment on terazosin pharmacokinetics have not been specifically studied; because terazosin is extensively metabolized by the liver, the label advises starting at the lowest initial dose (1 mg at bedtime) and titrating cautiously in patients with hepatic impairment. (2)
Monitoring
(2)Storage
Per the FDA label, store terazosin capsules/tablets at 20-25 degrees C (68-77 degrees F), with excursions permitted to 15-30 degrees C (59-86 degrees F); protect from moisture and keep out of reach of children.
Study the drug class: Alpha blockers
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Hypertension
Dose summary: Initial dose of 1 mg orally at bedtime for both hypertension and BPH, to reduce first-dose syncope risk; the dose may then be increased in a stepwise fashion (e.g., to 2 mg, then 5 mg, then 10 mg once daily) at intervals of at least 1-2 weeks based on blood pressure or symptom response, up to a maximum of 20 mg/day for BPH or per the treating physician's judgment for hypertension.
Renal context: Per the FDA label, clinically important pharmacokinetic changes have not been observed in renal impairment, and dosage modification is generally not necessary; supplemental dosing after hemodialysis is not required. (1) (2)
Frequently asked questions
What is Terazosin used for?
Terazosin is used to treat high blood pressure (hypertension) and symptoms of benign prostatic hyperplasia (BPH) in men.
How long does it take for Terazosin to work?
Some improvement in BPH symptoms may be noticed within a few days, but it may take up to 2–4 weeks for full benefits. Blood pressure effects are usually seen within hours of the first dose.
Can women take Terazosin?
Terazosin is not typically prescribed for women, as its main uses are for hypertension and BPH, which affects men. It should only be used in women if specifically directed by a doctor.
What should I do if I feel dizzy after taking Terazosin?
Sit or lie down immediately if you feel dizzy. Rise slowly from sitting or lying positions. If dizziness persists or is severe, contact your healthcare provider.
Can Terazosin be taken with other blood pressure medications?
Yes, but combining Terazosin with other antihypertensives may increase the risk of low blood pressure. Your doctor will monitor you closely and adjust doses as needed.
Is it safe to drink alcohol while taking Terazosin?
Alcohol can increase the risk of side effects such as dizziness or fainting. It is best to limit or avoid alcohol while taking Terazosin.
What should I tell my surgeon before cataract surgery?
Inform your eye surgeon if you are taking or have ever taken Terazosin, as it can affect your pupils during surgery (Intraoperative Floppy Iris Syndrome).
What happens if I take too much Terazosin?
Taking too much Terazosin can lead to a significant drop in blood pressure, causing severe dizziness, fainting, and a rapid heartbeat. In extreme cases, it may result in shock. If you suspect an overdose, seek immediate emergency medical attention. Do not attempt to self-treat, as professional medical intervention is crucial to manage the symptoms and stabilize your condition.
Can I drink alcohol while taking Terazosin?
Drinking alcohol while taking Terazosin is generally not recommended due to the increased risk of severe side effects. Both Terazosin and alcohol can lower blood pressure, and their combined effect can lead to excessive dizziness, lightheadedness, and fainting, particularly when standing up. This interaction can significantly impair your ability to drive or operate machinery safely. Consult your healthcare provider for personalized advice.
Is Terazosin safe during pregnancy?
Terazosin's safety during pregnancy is not definitively established, and it is categorized as a Pregnancy Category C drug. This means that animal reproduction studies have shown an adverse effect on the fetus, but there are no adequate and well-controlled studies in humans. Therefore, Terazosin should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Always consult your doctor to discuss the risks and benefits.
What is the mechanism of action of Terazosin?
Terazosin selectively blocks postsynaptic alpha-1 adrenergic receptors in vascular smooth muscle and the prostate. This blockade leads to vasodilation, decreased peripheral vascular resistance, and relaxation of smooth muscle in the bladder neck and prostate, improving urine flow in BPH and lowering blood pressure. (2)
What is the generic name of Terazosin?
The generic name is Terazosin. It is sold under brand names including Terazosin Accord, Terazosin Teva, Terazosin Sandoz, Hytrin, Terazosin Apotex, Terazosin.
What class of drug is Terazosin?
Terazosin is classed as: Alpha-1 adrenergic blocker (antihypertensive, urologic agent).
References
- UNKNOWNUNKNOWN · UNKNOWN · accessed 2026-08-07 · source 1
- Terazosin — Prescribing InformationU.S. Food and Drug Administration (presumed from source ID) · United States (presumed from source ID) · accessed 2026-08-07 · source 2
- TERAZOSIN HYDROCHLORIDE CAPSULE [APNAR PHARMA LP] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Terazosin — FDA approval record (Drugs@FDA ANDA075317)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- Terazosin — RxNorm normalized drug concept (RXCUI 235224)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient Terazosin names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- TEZRULY1 mg/mL · ani pharmaceuticals, inc.