Butalbital, aspirin, caffeine, and codeine and Methazolamide interaction
Butalbital, aspirin, caffeine, and codeine and Methazolamide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Methazolamide label · effective 2026-03-27
Caution is advised for patients receiving high-dose aspirin and methazolamide concomitantly, as anorexia, tachypnea, lethargy, coma, and death have been reported with concomitant use of high-dose aspirin and carbonic anhydrase inhibitors.
From the Butalbital, aspirin, caffeine, and codeine (BUTALBITAL, ASPIRIN, CAFFEINE and CODEINE PHOSPHATE) label · effective 2026-01-15
Examples: Acetazolamide, methazolamide Methotrexate Clinical Impact: Aspirin may enhance the toxicity of methotrexate by displacing it from its plasma protein binding sites and/or reducing its renal clearance.
Examples: Probenecid Carbonic Anhydrase Inhibitors Clinical Impact: Concurrent use with aspirin can lead to high serum concentrations of the carbonic anhydrase inhibitor and cause toxicity due to competition at the renal tubule for secretion.
Intervention: Consider reducing the dose of the carbonic anhydrase inhibitor and evaluate patient for any adverse effects from the carbonic anhydrase inhibitor.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot 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.