Aminophylline and Rifampin interaction
Aminophylline and Rifampin: 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 Rifampin label · effective 2026-05-05
Quinine Prevention or Management : Avoid concomitant use Decrease AUC by 75%-85% Telithromycin Decrease AUC by 86% Theophylline Decrease exposure by 20%-40% Effect of Other Drugs on Rifampin Concomitant antacid administration may reduce the absorption of rifampin.
From the Aminophylline label · effective 2026-05-22
…infants <3 months of age Sepsis with multi-organ failure Shock Cessation of Smoking Drug Interactions Adding a drug that inhibits theophylline metabolism (e.g., cimetidine, erythromycin, tacrine) or stopping a concurrently administered drug that enhances theophylline metabolism (e.g., carbamazepine, rifampin) (see PRECAUTIONS , Drug Interactions , Table II ).
Conversely, if theophylline is being initiated in a patient who is already taking a drug that enhances theophylline clearance (e.g., rifampin), the dose of theophylline required to achieve a therapeutic serum theophylline concentration will be larger.
Rifampin Increases theophylline clearance by increasing cytochrome P450 1A2 and 3A3 activity.
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.