Acetazolamide and Orphenadrine, aspirin, and caffeine interaction

Acetazolamide and Orphenadrine, aspirin, and caffeine: the Acetazolamide prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Acetazolamide label · effective 2026-01-23

Major

Caution is advised for patients receiving concomitant high-dose aspirin and acetazolamide, as anorexia, tachypnea, lethargy, metabolic acidosis, coma, and death have been reported.

Warningsnames Orphenadrine, aspirin, and caffeineView label on DailyMed

Moderate

Acetazolamide decreases urinary excretion of amphetamine and may enhance the magnitude and duration of their effect.

Drug interactionsby drug classView label on DailyMed

Minor

DRUG INTERACTIONS Aspirin - See WARNINGS .

Drug interactionsnames Orphenadrine, aspirin, and caffeineView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.