Terazosin and Hydrochlorothiazide Interaction

Drug interaction information between Terazosin and Hydrochlorothiazide.

Terazosin and Hydrochlorothiazide have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Terazosin and Hydrochlorothiazide. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Terazosin

Alpha-1 Blocker

Drug B

Hydrochlorothiazide

Thiazide Diuretic

How They Interact

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.

FDA Label Information

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;...

Frequently Asked Questions

What SPL severity band is on file for Terazosin + Hydrochlorothiazide?

Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Hydrochlorothiazide has 31 labeled pairs on file vs Terazosin's 15. In the minor band specifically: Terazosin has 15 (also Ibuprofen, Allopurinol, Aspirin, Atenolol); Hydrochlorothiazide has 27 (also Losartan, Spironolactone, Propranolol, Lithium).

What mechanism field is on file for Terazosin and Hydrochlorothiazide?

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.

Hydrochlorothiazide carries more major-labeled pairs than Terazosin

SPL source-record counts only. This page's band is minor · classes on file: Terazosin (Alpha-1 Blocker); Hydrochlorothiazide (Thiazide Diuretic).

Hydrochlorothiazide has 3 major-labeled pairs vs Terazosin's 0. This page itself is in the minor band, not the major band.

Terazosin

0 major · 0 moderate · 15 minor · 15 total

Hydrochlorothiazide

3 major · 1 moderate · 27 minor · 31 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.