NutriStack
Alcohol and Hydrochlorothiazide, a caution.
Hydrochlorothiazide lowers blood pressure partly through natriuresis and reduced plasma volume. Alcohol can potentiate orthostatic hypotension, so combining them may increase dizziness, fainting, falls, and dehydration risk. The risk is greater after starting hydrochlorothiazide, after dose increases, during illness, or with inadequate fluid intake.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Alcohol and Hydrochlorothiazide
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. Hydrochlorothiazide lowers blood pressure partly through natriuresis and reduced plasma volume. Alcohol can potentiate orthostatic hypotension, so combining them may increase dizziness, fainting, falls, and dehydration risk. The risk is greater after starting hydrochlorothiazide, after dose increases, during illness, or with inadequate fluid intake.
Mechanism. Hydrochlorothiazide increases sodium and water excretion and can lower intravascular volume. Alcohol reduces compensatory vasoconstriction during orthostatic stress, producing additive blood-pressure drops.
Recommendation. Limit alcohol when starting or changing hydrochlorothiazide. If you drink, hydrate appropriately, stand slowly, and avoid heavy intake; stop and seek medical advice if you faint or have persistent lightheadedness.
Sources (3)
- Narkiewicz K, Cooley RL, Somers VK. Alcohol potentiates orthostatic hypotension: implications for alcohol-related syncope. Circulation. 2000;101(4):398-402. PMID 10653831
- Palma JA, Kaufmann H. Management of Orthostatic Hypotension. Continuum (Minneap Minn). 2020;26(1):154-177. PMID 31996627
- Sica DA. Diuretic-related side effects: development and treatment. J Clin Hypertens (Greenwich). 2004;6(9):532-540. PMID 15365284
Stack Score
How this pair moves the number.
Effect on the composite score
If both Alcohol and Hydrochlorothiazide are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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