Pentoxifylline and Quinine interaction
Pentoxifylline and Quinine: the Quinine prescribing label describes 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 Quinine (QUININE SULFATE) label · effective 2025-10-31
Theophylline or Aminophylline In 20 healthy subjects who received multiple doses of quinine sulfate (648 mg every 8 hours x 7 days) with a single 300 mg oral dose of theophylline, the quinine mean C max and AUC were increased by 13% and 14% respectively.
Although no change in the quinine sulfate dosage regimen is necessary with concomitant theophylline or aminophylline, patients should be monitored closely for adverse reactions associated with quinine.
Theophylline or Aminophylline (CYP1A2 Substrate) In 19 healthy subjects who received multiple doses of quinine sulfate 648 mg every 8 hours x 7 days with a single 300 mg oral dose of theophylline, the mean theophylline AUC was 10% lower than when theophylline was given alone.
Therefore, if quinine sulfate is co-administered to patients receiving theophylline or aminophylline, plasma theophylline concentrations should be monitored frequently to ensure therapeutic concentrations.
There was no significant effect on mean theophylline C max .
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.