Quin-G and Tolterodine Tartrate Tablets

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Consumer information for this minor interaction is not currently available. Some minor drug interactions may not be clinically relevant in all patients. Minor drug interactions do not usually cause harm or require a change in therapy. However, your healthcare provider can determine if adjustments to your medications are needed.

Coadministration with drugs that are inhibitors of CYP450 2D6 may increase the plasma concentrations of tolterodine, which is primarily metabolized by this isoenzyme in patients that are extensive metabolizers, or EMs (approximately 93% of Caucasians and more than 98% of Asians and individuals of African descent). In an open-label, crossover study consisting of nine psychiatric patients, a potent CYP450 2D6 inhibitor like fluoxetine (20 mg orally once daily for 3 weeks) decreased the oral clearance of tolterodine (2 mg orally twice daily for 2.5 days) by 93% in EMs with two functional CYP450 2D6 genes and 80% in EMs with one functional gene. Oral clearance decreased by only 22% in poor metabolizers (no functional CYP450 2D6 gene), presumably due to relatively weak inhibition by fluoxetine of CYP450 3A4, the isoenzyme that metabolizes tolterodine in such individuals. This interaction is unlikely to produce clinically significant effects because of metabolic shunting to CYP450 3A4 in 2D6-deficient states. Moreover, since the active 5-hydroxymethyl metabolite (5-HM) generated by CYP450 2D6 is equipotent compared with tolterodine, and the sum of unbound serum concentrations of tolterodine and 5-HM are only 25% higher during the interaction, little alteration in the overall pharmacologic activity would be expected. Thus, dosage reductions should not be necessary.

Quin-G

Generic Name: quinidine

Brand name: Quin-G, Cardioquin, Quinora, Quinidex Extentabs, Quinaglute Dura-Tabs, Quin-Release

Synonyms: n.a.

What is Quin-G?

Tolterodine Tartrate Tablets

Generic Name: tolterodine

Brand name: Detrol, Detrol LA

Synonyms: Tolterodine

What is Tolterodine Tartrate Tablets?