FESOTERODINE FUMARATE (Page 3 of 7)

6.2 Post-marketing Experience

The following adverse reactions have been identified during post-approval use of fesoterodine fumarate extended-release tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Cardiac disorders: Palpitations

Central nervous system disorders: Dizziness, headache, somnolence

Eye disorders: Blurred vision

General disorders and administrative site conditions: Hypersensitivity reactions, including angioedema with airway obstruction, face edema

Skin and subcutaneous tissue disorders: Urticaria, pruritus

7 DRUG INTERACTIONS

7.1 Antimuscarinic Drugs

Coadministration of fesoterodine fumarate extended-release tablets 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.

7.2 CYP3A4 Inhibitors

Doses of fesoterodine fumarate extended-release tablets greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin [see Dosage and Administration (2.5)].
In a study in adults, coadministration of the strong CYP3A4 inhibitor ketoconazole with fesoterodine led to approximately a doubling of the maximum concentration (Cmax ) and area under the concentration versus time curve (AUC) of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine. Compared with CYP2D6 extensive metabolizers not taking ketoconazole, further increases in the exposure to 5-HMT were observed in subjects who were CYP2D6 poor metabolizers taking ketoconazole [see Clinical Pharmacology (12.3)].

There is no clinically relevant effect of moderate CYP3A4 inhibitors on the pharmacokinetics of fesoterodine. Following blockade of CYP3A4 by coadministration of the moderate CYP3A4 inhibitor fluconazole 200 mg twice a day for 2 days, the average (90% confidence interval) increase in Cmax and AUC of the active metabolite of fesoterodine was approximately 19% (11% to 28%) and 27% (18% to 36%) respectively. No dosing adjustments are recommended in the presence of moderate CYP3A4 inhibitors (e.g., erythromycin, fluconazole, diltiazem, verapamil and grapefruit juice).

The effect of weak CYP3A4 inhibitors (e.g., cimetidine) was not examined; it is not expected to be in excess of the effect of moderate inhibitors [see Clinical Pharmacology (12.3)].

Pediatric use information is approved for Pfizer Inc.’s TOVIAZ® (fesoterodine fumarate) extended-release tablets. However, due to Pfizer Inc.’s marketing exclusivity rights, this drug product is not labeled with that information.

7.3 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 fesoterodine fumarate extended-release tablets 8 mg. The terminal half-life of the active metabolite was not changed.

7.4 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.

7.5 Drugs Metabolized by Cytochrome P450

In vitro data indicate that at therapeutic concentrations, the active metabolite of fesoterodine does not have the potential to inhibit or induce Cytochrome P450 enzyme systems [see Clinical Pharmacology (12.3)].

7.6 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 [see Clinical Pharmacology (12.3)].

7.7 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 [see Clinical Pharmacology (12.3)].

7.8 Drug-Laboratory Test Interactions

Interactions between fesoterodine fumarate extended-release tablets and laboratory tests have not been studied.

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

There are no available data with the use of fesoterodine fumarate extended-release tablets in pregnant women and adolescents to evaluate for a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. In animal reproduction studies, oral administration of fesoterodine to pregnant mice and rabbits during organogenesis resulted in fetotoxicity at maternal exposures that were 6 and 3 times respectively the maximum recommended human dose (MRHD) of 8 mg/day, based on AUC (see Data). The background risk of major birth defects and miscarriage for the indicated population are unknown. However, in the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data

Animal Data

No dose-related teratogenicity was observed in reproduction studies performed in mice and rabbits. In mice at 6 to 27 times the expected exposure at the maximum recommended human dose (MRHD) of 8 mg based on AUC (75 mg/kg/day, oral), increased resorptions and decreased live fetuses were observed. One fetus with cleft palate was observed at each dose (15, 45, and 75 mg/kg/day), at an incidence within the background historical range. In rabbits treated at 3 to 11 times the MRHD (27 mg/kg/day, oral), incompletely ossified sternebrae (retardation of bone development) and reduced survival were observed in fetuses. In rabbits at 9 to 11 times the MRHD (4.5 mg/kg/day, subcutaneous), maternal toxicity and incompletely ossified sternebrae were observed in fetuses (at an incidence within the background historical range). In rabbits at 3 times the MRHD (1.5 mg/kg/day, subcutaneous), decreased maternal food consumption in the absence of any fetal effects was observed. Oral administration of 30 mg/kg/day fesoterodine to mice in a pre- and post-natal development study resulted in decreased body weight of the dams and delayed ear opening of the pups. No effects were noted on mating and reproduction of the F1 dams or on the F2 offspring.

8.2 Lactation

Risk Summary

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 fumarate extended-release tablets and any potential adverse effects on the breastfed child from fesoterodine fumarate extended-release tablets or from the underlying maternal condition.

8.4 Pediatric Use

The safety and effectiveness of fesoterodine fumarate extended-release tablets have not been established in pediatric patients younger than 6 years of age or weighing 25 kg or less.

Pediatric use information is approved for Pfizer Inc.’s TOVIAZ® (fesoterodine fumarate) extended-release tablets. However, due to Pfizer Inc.’s marketing exclusivity rights, this drug product is not labeled with that information.

8.5 Geriatric Use

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

Of the 1,567 patients who received fesoterodine fumarate extended-release tablets 4 mg or 8 mg orally once daily in Phase 2 and 3, placebo-controlled, efficacy and safety studies for OAB, 515 (33%) were 65 years of age or older, and 140 (9%) were 75 years of age or older. No overall difference in effectiveness was observed between patients younger than 65 years of age and those 65 years of age or older in these studies. However, the incidence of antimuscarinic adverse reactions, including dry mouth, constipation, dyspepsia, increase in residual urine, dizziness (8 mg only) and urinary tract infection, was higher in patients 75 years of age and older as compared to younger patients [see Clinical Studies (14.1) and Adverse Reactions (6)].

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2022. All Rights Reserved.