terazosin monohydrochloride dihydrate at a glance
Medicine class
Alpha-1 adrenoceptor blocker
Licensed uses
Mild to moderate hypertension and urinary obstruction caused by BPH in adults
Main practical caution
Dizziness, postural hypotension or fainting can occur, particularly when treatment is started, restarted or changed.
What is terazosin monohydrochloride dihydrate used for?
Licensed adult uses include:
Mild to moderate hypertension, alone where other agents are unsuitable or ineffective, or alongside other blood-pressure treatments.
Symptomatic urinary obstruction caused by benign prostatic hyperplasia.
How does terazosin monohydrochloride dihydrate work?
Terazosin blocks alpha-1 receptors, relaxing blood vessels and smooth muscle around the prostate, urethra and bladder outlet. This lowers vascular resistance and improves urinary flow. It does not directly shrink the prostate.
terazosin monohydrochloride dihydrate preparations and strengths
Tablet
Route: Oral
Strengths: 2 mg, 5 mg, 10 mg
How to take terazosin monohydrochloride dihydrate
Swallow the tablet exactly as prescribed and follow the labelled pack sequence where supplied. It may be taken with or without food. Rise slowly from sitting or lying positions, and avoid alcohol because it may worsen dizziness, light-headedness or drowsiness.
Do not drive or operate machinery if dizzy, light-headed or drowsy.
Do not stop treatment solely because symptoms improve.
Tell the prescriber before restarting after an interruption.
terazosin monohydrochloride dihydrate side effects
Common or expected effects
- Dizziness or light-headedness, particularly on standing
- Weakness, drowsiness or headache
- Nausea or digestive discomfort
- Blocked nose
- Palpitations
- Swelling of the hands or feet
Get urgent medical advice
- Fainting or marked low blood pressure
- Severe allergic reaction, including facial or throat swelling or breathing difficulty
- Chest pain or a fast or irregular heartbeat
- Persistent painful erection
- Unexpected bruising or prolonged bleeding
terazosin monohydrochloride dihydrate in pregnancy
Safety during pregnancy has not been established. It should not be used unless the expected benefit is considered to outweigh the risk, so specialist or prescriber review is important.
terazosin monohydrochloride dihydrate while breastfeeding
It is unknown whether terazosin enters human milk. A prescriber should assess the need for treatment, available alternatives and the infant’s age and health.
terazosin monohydrochloride dihydrate interactions
Interactions may increase or oppose terazosin’s blood-pressure effect.
Sildenafil, tadalafil, vardenafil and other PDE-5 inhibitors
May cause symptomatic or postural hypotension; prescriber coordination is required.
Other antihypertensives
Additive blood-pressure lowering may increase dizziness or fainting.
Diuretics
May increase hypotension and dizziness.
Nitrates and other vasodilators
Additive vasodilation may cause excessive blood-pressure reduction.
Common questions about terazosin monohydrochloride dihydrate
Answers are fully visible for fast scanning and source review.
Does terazosin shrink an enlarged prostate?
No. It relaxes smooth muscle around the prostate and bladder outlet to improve urinary flow but does not directly reduce prostate size.
Why can terazosin make me dizzy when I stand up?
It relaxes blood vessels, so blood pressure may fall when standing, causing light-headedness or fainting.
Can terazosin be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.