Drug Interactions between Toviaz and vibegron

MONITOR: Coadministration with moderate inhibitors of CYP450 3A4 such as grapefruit juice may increase the plasma concentrations of fesoterodine's active metabolite, 5-hydroxymethyl tolterodine, which is partially metabolized by the isoenzyme. The possibility of prolonged and/or increased pharmacologic effects of fesoterodine should be considered. Because 5-hydroxymethyl tolterodine is also metabolized by CYP450 2D6, the clinical significance of the interaction may be greater in patients who are CYP450 2D6-deficient, or so-called poor metabolizers of CYP450 2D6 (approximately 7% of Caucasians and less than 2% of Asians and individuals of African descent) who may rely more on the 3A4 metabolic pathway for clearance of the drug.

MANAGEMENT: Caution is advised if fesoterodine is administered with grapefruit or grapefruit juice. Patients should be advised to notify their physician if they experience potential adverse effects of fesoterodine such as irregular heartbeat, blurry vision, difficulty urinating, dry mouth, headache, drowsiness, dizziness, gastrointestinal upset, or constipation.

Switch to consumer interaction data

The recommended maximum number of medicines in the 'anticholinergics/antispasmodics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'anticholinergics/antispasmodics' category:

• Toviaz (fesoterodine)
• vibegron

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.