CONCOMITANT USE OF PYRAZINAMIDE WITH FAVIPIRAVIR INCREASES THE LEVELS OF URIC ACID. REPAGLINIDE: FAVIPIRAVIR INHIBITS THE METABOLISM OF REPAGLINIDE THROUGH THE CYP2C8 PATHWAY, THUS INCREASING ITS POTENTIAL TO CAUSE TOXICITY.THEOPHYLLINE INCREASES THE BLOOD LEVELS OF FAVIPIRAVIR AND ADVERSE REACTIONS TO FAVIPIRAVIR MAY OCCUR. FAMCICLOVIR, SULINDAC: EFFICACY OF THESE DRUGS MAY BE REDUCED WHEN COADMINISTERED WITH FAVIPIRAVIR. ACYCLOVIR MAY DELAY THE CONVERSION OF FAVIPIRAVIR INTO THE ACTIVE MOIETY, THUS REDUCING ITS ANTIVIRAL EFFICACY.