Skip to main content

Drug Interactions between fesoterodine and Terbinex with Eco Formula

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Moderate

terbinafine fesoterodine

Applies to: Terbinex with Eco Formula (hydroxypropyl chitosan / terbinafine topical) and fesoterodine

MONITOR: Coadministration with inhibitors of CYP450 2D6 may increase the plasma concentrations of fesoterodine's active metabolite, 5-hydroxymethyl tolterodine, which is partially metabolized by the isoenzyme. The interaction has not been examined in pharmacokinetic studies. In poor metabolizers of CYP450 2D6, representing maximum CYP450 2D6 inhibition, 5-hydroxymethyl tolterodine peak plasma concentration (Cmax) and systemic exposure (AUC) are increased 1.7- and 2-fold, respectively, relative to extensive metabolizers.

MANAGEMENT: No initial dosing adjustments are recommended when fesoterodine is used in combination with CYP450 2D6 inhibitors. 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.

References

  1. "Product Information. Toviaz (fesoterodine)." Pfizer U.S. Pharmaceuticals Group (2008):

Switch to consumer interaction data

Drug and food interactions

Moderate

fesoterodine food

Applies to: fesoterodine

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.

References

  1. "Product Information. Toviaz (fesoterodine)." Pfizer U.S. Pharmaceuticals Group (2008):

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer