Fesoterodine Fumarate

Adult Overactive Bladder: Fesoterodine is indicated for the treatment of overactive bladder (OAB) in adults with symptoms of urge urinary incontinence, urgency, and frequency.

Pediatric Neurogenic Detrusor Overactivity: Fesoterodine is indicated for the treatment of neurogenic detrusor overactivity (NDO) in pediatric patients 6 years of age and older with a body weight greater than 25 kg.

Fesoterodine is a competitive muscarinic receptor antagonist. After oral administration, fesoterodine is rapidly and extensively hydrolyzed by nonspecific esterases to its active metabolite, 5-hydroxymethyl tolterodine, which is responsible for the antimuscarinic activity of fesoterodine. Muscarinic receptors play a role in contractions of urinary bladder smooth muscle. Inhibition of these receptors in the bladder is presumed to be the mechanism by which fesoterodine produces its effects.

In a urodynamic study involving patients with involuntary detrusor contractions, the effects after the administration of fesoterodine on the volume at first detrusor contraction and bladder capacity were assessed. Administration of fesoterodine increased the volume at first detrusor contraction and bladder capacity in a dose-dependent manner. These findings are consistent with an antimuscarinic effect on the bladder.

Overactive Bladder in adults: The recommended starting dosage is 4 mg orally once daily. Based upon individual response and tolerability, increase to the maximum dosage of 8 mg once daily.

Neurogenic Detrusor Overactivity in pediatric patients 6 years and older:

• Pediatric Patients Weighing Greater than 25 kg and up to 35 kg: The recommended dosage is 4 mg orally once daily. If needed, dosage may be increased to 8 mg orally once daily.
• Pediatric Patients Weighing Greater than 35 kg: The recommended starting dosage is 4 mg orally once daily. After one week, increase to 8 mg orally once daily.

Administration: Swallow whole with liquid. Do not chew, divide, or crush. Take with or without food.

Pediatric Use: The safety and effectiveness of Toviaz have been established for the treatment of neurogenic detrusor overactivity (NDO) in pediatric patients aged 6 years and older and weighing greater than 25 kg.

Geriatric Use: No dose adjustment is recommended for the elderly. The pharmacokinetics of fesoterodine are not significantly influenced by age.

Antimuscarinic Drugs: Coadministration of Fesoterodine 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. Anticholinergic agents may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility.

CYP3A4 Inhibitors: Doses of Fesoterodine greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin. The Fesoterodine dose in pediatric patients taking strong CYP3A4 inhibitors is recommended to be reduced to 4 mg once daily in patients >35 kg and is not recommended in patients weighing greater than 25 kg and up to 35 kg.

CYP3A4 Inducers: No dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine. Following induction of CYP3A4 by coadministration of rifampin 600 mg once a day, Cmax and AUC of the active metabolite of fesoterodine decreased by approximately 70% and 75%, respectively, after oral administration of Toviaz 8 mg. The terminal half-life of the active metabolite was not changed.

CYP2D6 Inhibitors: The interaction with CYP2D6 inhibitors was not tested clinically. In poor metabolizers for CYP2D6, representing a maximum CYP2D6 inhibition, Cmax and AUC of the active metabolite are increased 1.7- and 2-fold, respectively. No dosing adjustments are recommended in the presence of CYP2D6 inhibitors.

Oral Contraceptives: In the presence of fesoterodine, there are no clinically significant changes in the plasma concentrations of combined oral contraceptives containing ethinyl estradiol and levonorgestrel.

Warfarin: A clinical study has shown that fesoterodine 8 mg once daily has no significant effect on the pharmacokinetics or the anticoagulant activity (PT/INR) of warfarin 25 mg. Standard therapeutic monitoring for warfarin should be continued

Fesoterodine is contraindicated in patients with any of the following:

• known or suspected hypersensitivity to Fesoterodine or any of its ingredients, or to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules. Reactions have included angioedema.
• urinary retention
• gastric retention
• uncontrolled narrow-angle glaucoma.

Most frequently reported adverse events with Fesoterodine in adult patients with OAB (≥4%) were: dry mouth (placebo, 7%; Fesoterodine 4 mg, 19%; Fesoterodine 8 mg, 35%) and constipation (placebo, 2%; Fesoterodine 4 mg, 4%; Fesoterodine 8 mg, 6%).

Most frequently reported adverse reactions with Fesoterodine in pediatric patients (≥2%) with NDO were: diarrhea, urinary tract infection (UTI), dry mouth, constipation, abdominal pain, nausea, weight increased, and headache.

There are no available data with the use of Fesoterodine in pregnant women and adolescents to evaluate for a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There is no information on the presence of fesoterodine in human milk, the effects on the breastfed child, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Fesoterodine and any potential adverse effects on the breastfed child from Fesoterodine or from the underlying maternal condition.

Angioedema: Promptly discontinue Fesoterodine and provide appropriate therapy.
Urinary Retention: Fesoterodine is not recommended in patients with clinically significant bladder outlet obstruction because of the risk of urinary retention.
Decreased Gastrointestinal Motility: Fesoterodine is not recommended for use in patients with decreased gastrointestinal motility, such as those with severe constipation.
Worsening of Narrow-Angle Glaucoma: Use Fesoterodine with caution in patients being treated for narrow-angle glaucoma.
Central Nervous System Effects: Somnolence has been reported with Fesoterodine. Advise patients not to drive or operate heavy machinery until they know how Fesoterodine affects them.
Worsening of Myasthenia Gravis Symptoms: Use Fesoterodine with caution in patients with myasthenia gravis.

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.