Butalbital, acetaminophen, and caffeine and Isoniazid interaction
Butalbital, acetaminophen, and caffeine and Isoniazid: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Butalbital, acetaminophen, and caffeine (BUTALBITAL, ACETAMINOPHEN AND CAFFEINE) label · effective 2026-05-19
Drug Interactions The CNS effects of butalbital may be enhanced by monoamine oxidase (MAO) inhibitors.
From the Isoniazid label · effective 2026-04-27
Acetaminophen A report of severe acetaminophen toxicity was reported in a patient receiving isoniazid.
It is believed that the toxicity may have resulted from a previously unrecognized interaction between isoniazid and acetaminophen and a molecular basis for this interaction has been proposed.
Studies have demonstrated that pretreatment with isoniazid potentiates acetaminophen hepatotoxicity in rats 1,2 .
Theophylline A recent study has shown that concomitant administration of isoniazid and theophylline may cause elevated plasma levels of theophylline, and in some instances a slight decrease in the elimination of isoniazid.
Since the therapeutic range of theophylline is narrow, theophylline serum levels should be monitored closely, and appropriate dosage adjustments of theophylline should be made 7 .
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.