Prescription medication · Alpha-1 Blocker

terazosin

Also sold as Hytrin. Terazosin is used to treat enlarged prostate in men.

Data updated 2026-05-15

7,436
FDA reportsLightly reported
15
InteractionsSeveral interactions
$0.15
Generic price (NADAC)

What the data shows

terazosin (Hytrin) is a prescription Alpha-1 Blocker, reported less often than most tracked drugs (7,436 FDA reports), with 15 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

terazosin (Hytrin) is a prescription Alpha-1 Blocker. Terazosin is used to treat enlarged prostate in men.

Terazosin is a medicine that can help men with enlarged prostate and also treat high blood pressure. It works by relaxing certain muscles in your body.

Drug Pricing (NADAC)

Generic Price

$0.15/unit

Generic Available

Yes (5 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

View Alternatives → Compare with Another Drug → Full Side Effects Report →

What it does

Terazosin is used to treat enlarged prostate in men.

Common side effects

Feeling weak or tired, Dizziness, Stuffy nose

Key warnings

Be careful when you first start taking terazosin, as it can cause your blood pressure to drop too low.

The sections below are summarized in plain English from terazosin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Terazosin belongs to a class of drugs called alpha-1 blockers. It works by relaxing the muscles in the prostate and bladder neck, making it easier to urinate. It also relaxes blood vessels, which helps to lower blood pressure.

Side Effects (from patient reports)

Based on 7,436 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for terazosin, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS) As of 2025

Reports over time

Adverse-event reports filed for terazosin each year to the FDA Adverse Event Reporting System (FAERS).

0200400600800 200220062009201220152018202120242025 247

Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.

Where terazosin sits

terazosin has more FDA adverse-event reports than 33% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.

fewest reports most reports

Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is terazosin; the line is the median (50th percentile).

FDA Adverse Event Report Analysis

Detailed analysis of 7,436 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2002–2025.

Total Reports

7,436

Reports Mentioning Death

836

11.2% of reports — not proof of cause

Hospitalization Reports

2,657

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 1,047 (15%)
Male 5,875 (85%)

Age Distribution

0–17 12
18–44 162
45–64 1,186
65–74 1,637
75+ 2,102

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
2 FATIGUE 466
3 DIARRHOEA 395
4 DIZZINESS 385
5 DYSPNOEA 383
6 ASTHENIA 351
7 ACUTE KIDNEY INJURY 331
8 DEATH 325
9 CHRONIC KIDNEY DISEASE 319
10 RENAL FAILURE 301
12 FALL 283
13 NAUSEA 282
14 PAIN 267
15 PNEUMONIA 253
16 HYPOTENSION 252
17 HEADACHE 249

Reactions in Death Reports

DEATH 325
ACUTE KIDNEY INJURY 61
PNEUMONIA 61
RENAL FAILURE 57
CHRONIC KIDNEY DISEASE 55
FALL 46
CARDIAC ARREST 45
DYSPNOEA 45
ASTHENIA 38
END STAGE RENAL DISEASE 38

Reactions in Hospitalization Reports

FALL 198
PNEUMONIA 192
DYSPNOEA 187
ACUTE KIDNEY INJURY 179
ASTHENIA 174
HYPOTENSION 157
GASTROINTESTINAL HAEMORRHAGE 149
DIZZINESS 148
FATIGUE 148
RENAL FAILURE 140

Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

Be careful when you first start taking terazosin, as it can cause your blood pressure to drop too low. This can lead to dizziness or fainting. Take your first dose at bedtime and be careful when standing up.

Known Drug Interactions

Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...

Mechanism: Both drugs are used to lower blood pressure. Taking them at the same time can cause an additive effect, making your blood pressure drop lower than usual.

Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...

Mechanism: Ibuprofen belongs to a class of drugs that can cause the body to retain fluid. This may make blood pressure medications like terazosin less effective.

Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...

Mechanism: These medications have been used together in clinical trials without any reported problems. There is no known negative interaction between them.

minor aspirin

Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...

Mechanism: These drugs have been used together in many patients without any harmful effects being reported. They do not typically interfere with each other.

Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...

Mechanism: Both of these medications work to lower blood pressure. Using them together can cause your blood pressure to drop more than if you took only one.

Check all your medications →

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

Can I take terazosin with other blood pressure medicines?
Yes, terazosin can be used with other blood pressure medicines, but your doctor may need to adjust the doses.
How long does it take for terazosin to start working?
You may notice an improvement in your symptoms within a few weeks of starting terazosin.
Can terazosin cause dizziness?
Yes, dizziness is a common side effect of terazosin, especially when you first start taking it.
Can I drink alcohol while taking terazosin?
Talk to your doctor about drinking alcohol while taking terazosin, as it can increase the risk of dizziness.
What should I do if I feel dizzy after taking terazosin?
Lie down until the dizziness passes. Be careful when standing up.
Can terazosin affect my sex life?
Yes, terazosin can cause impotence (trouble getting an erection) in some men.
Is it safe to drive while taking terazosin?
Be careful driving or operating machinery until you know how terazosin affects you, as it can cause dizziness.
What are the different strengths of terazosin capsules?
Terazosin capsules come in 1 mg, 2 mg, 5 mg, and 10 mg strengths.
How should I dispose of unused terazosin capsules?
Talk to your pharmacist about how to properly dispose of unused terazosin capsules.
Can I stop taking terazosin suddenly?
Do not stop taking terazosin suddenly without talking to your doctor, as this can cause your blood pressure to increase.
What are the common side effects of terazosin?
The registry lists Feeling weak or tired, Dizziness, Stuffy nose, Headache among the most-reported FAERS reaction terms for terazosin. The compiled record contains 7,436 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does terazosin interact with other medications?
The registry has 15 documented interaction rows for terazosin. Notable source-record pairings include hydrochlorothiazide, ibuprofen, allopurinol. These rows are not a complete medication review.
What drug class is terazosin?
terazosin belongs to the Alpha-1 Blocker drug class. It requires a prescription (Rx). Terazosin is used to treat enlarged prostate in men.
What pregnancy or breastfeeding source fields are listed for terazosin?
The FDA label for terazosin contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.

Other drugs grouped near terazosin - same-class peers and common alternatives.

Compare terazosin vs acebutolol side-by-side →

Compare beyond drug class

Nationwide peers by FAERS volume & death-report share

Two PlainMeds-derived comparison paths for terazosin: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.

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What the FDA Data Shows for terazosin

The FDA label for terazosin (sold under brand names such as Hytrin) classifies it as a prescription-only medication in the Alpha-1 Blocker class. Terazosin is used to treat enlarged prostate in men. Official labeling lists 4 commonly reported side effects, including Feeling weak or tired, Dizziness, Stuffy nose.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 7,436 voluntary reports. The database also lists 15 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.15.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: July 20, 2023

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page