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allopurinol vs terazosin

Side-by-side comparison of allopurinol and terazosin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

minor Known Drug Interaction

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;...

Recommendation: You can continue taking both medications as prescribed. No special monitoring is usually necessary for this combination.

Drug Class
allopurinol Xanthine Oxidase Inhibitor
terazosin Alpha-1 Blocker
Type
allopurinol Prescription
terazosin Prescription
Summary
allopurinol

Allopurinol is a medicine that lowers uric acid levels in your body. It helps prevent gout attacks and other problems caused by high uric acid.

terazosin

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.

What It Treats
allopurinol

This medicine is used to manage gout in adults. Gout causes painful attacks, joint damage, and kidney problems. Allopurinol is also used in adults and children with leukemia, lymphoma, and solid tumors who are getting cancer treatment. It helps manage high uric acid caused by the cancer treatment. It can also help adults who get calcium oxalate kidney stones often.

terazosin

Terazosin is used to treat enlarged prostate in men. An enlarged prostate can cause problems with urination. Terazosin helps improve urine flow and reduce symptoms. It is also used to treat high blood pressure, either alone or with other medicines.

How It Works
allopurinol

Allopurinol works by blocking an enzyme called xanthine oxidase. This enzyme helps your body make uric acid. By blocking it, allopurinol reduces the amount of uric acid in your blood and urine.

terazosin

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.

Common Side Effects
allopurinol
  • Diarrhea
  • Nausea
  • Increased liver enzyme levels
  • Gout attacks
  • Skin rash
terazosin
  • Feeling weak or tired
  • Dizziness
  • Stuffy nose
  • Headache
FAERS Reports
allopurinol
  • Diarrhea 8,423
  • Tiredness 7,965
  • Difficulty breathing 7,659
  • Feeling sick to your stomach 7,061
  • Death 6,664
terazosin
  • Tiredness 466
  • Diarrhea 395
  • Feeling dizzy 385
  • Difficulty breathing 383
  • Weakness 351
Serious Warnings
allopurinol

Allopurinol can cause serious skin reactions that can be deadly. Stop taking this medicine and get medical help right away if you get a skin rash or any other signs of an allergic reaction.

terazosin

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.

Pregnancy
allopurinol

Allopurinol may harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is not recommended to breastfeed while taking this medicine because it can pass into breast milk.

terazosin

It is not known if terazosin can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if terazosin passes into breast milk, so talk to your doctor if you are breastfeeding.

Also Compare, Nearby Drugs

Compare allopurinol with

Compare terazosin with

How to Read This allopurinol vs terazosin Comparison

allopurinol is classified in the Xanthine Oxidase Inhibitor drug class, while terazosin sits within the Alpha-1 Blocker class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, allopurinol has 37,772 submissions while terazosin has 1,980. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to these medications have been used together in clinical trials without any reported problems. there is no known negative interaction between them.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between allopurinol and terazosin - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.