PTCE Top 200 · #16

Hydrochlorothiazide

Microzide

Hydrochlorothiazide is the generic name for the brand-name drug Microzide. It is a thiazide diuretic used to treat hypertension, edema. On the PTCE Top 200 drug list, Hydrochlorothiazide ranks #16 and is one of the most frequently tested cardiovascular medications — commonly quizzed on its brand–generic pair, drug class, and key side effects.

Generic name	Hydrochlorothiazide
Brand name(s)	Microzide
Drug class	Thiazide diuretic
Class group	Cardiovascular
Common use	hypertension, edema
DEA schedule	Unscheduled
Availability	Prescription only (Rx)

What is Hydrochlorothiazide used for?

Thiazide diuretic for hypertension; also used to treat edema due to heart failure, liver disease, or kidney disorders.

What drug class is Hydrochlorothiazide?

Hydrochlorothiazide is a Thiazide diuretic in the Cardiovascular group. Knowing the class is the fastest way to predict its uses, side effects, and the brand↔generic pairs the PTCE tests.

Common side effects of Hydrochlorothiazide

arrow_rightLow potassium (hypokalemia)
arrow_rightDizziness
arrow_rightIncreased urination
arrow_rightPhotosensitivity
arrow_rightIncreased blood glucose or uric acid

Major interactions

arrow_rightLithium levels can increase (toxicity risk)
arrow_rightNSAIDs may blunt diuretic/antihypertensive effect
arrow_rightDigoxin: hypokalemia increases arrhythmia risk
arrow_rightOther antihypertensives may add hypotension

Is Hydrochlorothiazide a controlled substance?

No. Hydrochlorothiazide is not a federally controlled substance (it is unscheduled by the DEA).

How to remember Hydrochlorothiazide (PTCE mnemonic)

MICROzide MICRO-doses the thiazide — HCTZ pees out pressure. ↓K+, ↓Na+, ↑uric acid (gout), photosensitivity; sulfa allergy.

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PTCE exam tip

HCTZ is a thiazide “water pill” for blood pressure; watch for low potassium. Note that “HCTZ” is a common abbreviation — but unsafe abbreviations are themselves a patient-safety topic.