Fesoterodine and Tolterodine interaction

Toviaz is contraindicated in patients with any of the following: • known or suspected hypersensitivity to Toviaz or any of its ingredients, or to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules [see Clinical Pharmacology (12.1) ] .

…Precautions (5.1) ] • urinary retention [see Warnings and Precautions (5.2) ] • gastric retention [see Warnings and Precautions (5.3) ] • uncontrolled narrow-angle glaucoma [see Warnings and Precautions (5.4) ] • Known or suspected hypersensitivity to Toviaz or any of its ingredients or to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules.

Urinary Retention in Adult Patients With Bladder Outlet Obstruction The use of Toviaz, like other antimuscarinic drugs, in patients with clinically significant bladder outlet obstruction, including patients with urinary retention, may result in further urinary retention and kidney injury.

Antimuscarinic Drugs Coadministration of Toviaz with other antimuscarinic agents that produce dry mouth, constipation, urinary retention, and other anticholinergic pharmacological effects may increase the frequency and/or severity of such effects.

In a study in adults, coadministration of the strong CYP3A4 inhibitor ketoconazole with fesoterodine led to approximately a doubling of the maximum concentration (C max ) and area under the concentration versus time curve (AUC) of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine.

DETROL is also contraindicated in patients who have demonstrated hypersensitivity to the drug or its ingredients, or to fesoterodine fumarate extended-release tablets which, like DETROL, are metabolized to 5-hydroxymethyl tolterodine.