The most common side effect with Toviaz (seen in more than 1 patient in 10) is dry mouth. For the full list of all side effects reported with Toviaz, see the package leaflet.

Toviaz must not be used in people who are hypersensitive (allergic) to fesoterodine, to any of the other ingredients, to peanut or to soya. Toviaz must also not be used in patients with:

• urinary retention (difficulty in passing urine);
• gastric retention (when the stomach does not empty properly);
• uncontrolled narrow-angle glaucoma (increased eye pressure even with treatment);
• myasthenia gravis (a disease of the nerves causing muscle weakness);
• severe hepatic impairment (severe liver disease);
• severe ulcerative colitis (severe inflammation of the large intestine causing ulceration and bleeding);
• toxic megacolon (a very serious complication of colitis).

Toviaz must not be given to patients with moderate liver or moderate to severe kidney disease at the same time as strong CYP3A4 inhibitor medicines. These include medicines such as ketoconazole and itraconazole (used to treat fungal infections), atazanavir, indinavir, nelfinavir, ritonavir and saquinavir (medicines used in HIV-positive patients), clarithromycin and telithromycin (antibiotics), and nefazodone (used to treat depression).