Effects of hepatic dysfunction on the single-dose pharmacokinetics of fesoterodine

Fesoterodine clinical efficacy and safety for the treatment of overactive bladder in relation to patient profiles: a systematic review

OBJECTIVE

To summarize published evidence on the pharmacology, efficacy, and safety of fesoterodine for the treatment of overactive bladder (OAB) symptoms in relation to patient clinical and demographic profiles.

METHODS

A systematic review of published articles on fesoterodine was conducted via a PubMed search. Articles were identified using the search term fesoterodine, with limits of human species and abstract available. Review and meta-analysis articles, validation studies, articles focused on treatment compliance/adherence, meeting abstracts, and articles not focused on oral fesoterodine administration in human subjects were excluded. Data from retained articles were summarized descriptively.

RESULTS

Of 137 articles identified, 61 (15 articles on the pharmacology and 46 articles on the efficacy and/or safety of fesoterodine) met inclusion criteria. Superiority trials demonstrated the additional efficacy of fesoterodine 8 mg versus fesoterodine 4 mg and tolterodine extended release 4 mg in treating OAB. Prospective trials in specific patient populations indicated beneficial effects of fesoterodine in elderly patients, vulnerable elderly patients, patients dissatisfied with or with a suboptimal response to previous antimuscarinic therapy, patients with urge urinary incontinence (UUI) or nocturnal urgency, and men with persistent LUTS during alpha-blocker treatment. With two effective doses, the fesoterodine dose can be adjusted to achieve optimal efficacy and tolerability in individual patients. The most common adverse events during fesoterodine treatment are dry mouth and constipation.

CONCLUSIONS

Extensive evidence demonstrates the efficacy and safety of fesoterodine in relieving OAB symptoms, including urgency, urinary frequency, UUI, and nocturnal urgency, in patients with various clinical and demographic profiles. Trial results provide valuable information on fesoterodine treatment in specific patient populations, including both elderly and vulnerable elderly patients. Potential limitations of this review are that only English language articles in PubMed were searched and included.

Fesoterodine fumarate and the oxybutynin ring for the treatment of urinary incontinence in women

INTRODUCTION

Urinary incontinence (UI) is a prevalent condition among women of all ages. It can have a significant negative impact on women's quality of life causing not only physical but also psychological distress.

AREAS COVERED

This article aims to provide a review of the pharmacology, efficacy, safety and tolerability of fesoterodine fumarate (the newest anticholinergic launched in the UK) and the oxybutynin vaginal ring (the newest route of drug delivery in development) in the treatment of urgency UI.

EXPERT OPINION

Fesoterodine is now a well-established treatment option; however, as with all oral anticholinergic agents its use is hindered by side effects. The efficacy of the oxybutynin ring has only been demonstrated in small studies. Larger clinical trials assessing the efficacy, tolerability and acceptability are required before appropriate recommendations can be made.

Evaluation of fesoterodine fumarate for the treatment of an overactive bladder

INTRODUCTION

Fesoterodine fumarate is an approved drug for overactive bladder. The aim of this study is to review the preclinical and most up to date clinical data on fesoterodine, with a special emphasis on its unique pharmacokinetic features and its implications on safety and tolerability in various patient populations.

AREAS COVERED

In this review, the authors extensively reviewed available literature via PubMed search regarding fesoterodine, covering its mechanism of action, pharmacodynamics and pharmacokinetics, clinical efficacy, safety, and tolerability.

EXPERT OPINION

Fesoterodine is an anti-muscarinic agent with a unique pharmacokinetic profile. It is a prodrug that is rapidly metabolized to its active form by nonspecific plasma esterases. Its metabolism is independent of the cytochrome P450 enzyme system. This along with its dual excretion pathways and minimal central nervous system penetration leads to less variability in drug exposure and allowance of administration in those with mild to moderate renal and hepatic insufficiency and in the geriatric population.

Effects of the moderate CYP3A4 inhibitor, fluconazole, on the pharmacokinetics of fesoterodine in healthy subjects

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Available data suggest that fesoterodine dosage should not exceed 4 mg once daily when taken concomitantly with potent CYP3A4 inhibitors, such as ketoconazole. Currently, no information is available on whether dose adjustment is necessary when fesoterodine is administered with a moderate CYP3A4 inhibitor.

WHAT THIS STUDY ADDS

This study shows that adjustment of fesoterodine dose is not warranted when co-administered with a moderate CYP3A4 inhibitor.

AIMS

To assess the effects of fluconazole, a moderate CYP3A4 inhibitor, on the pharmacokinetics (PK) and safety/tolerability of fesoterodine.

METHODS

In this open-label, randomized, two-way crossover study, 28 healthy subjects (18-55 years) received single doses of fesoterodine 8 mg alone or with fluconazole 200 mg. PK endpoints, including the area under the plasma concentration-time curve from 0 to infinity (AUC(0,∞)), maximum plasma concentration (C(max) ), time to C(max) (t(max) ), and half-life (t(1/2) ), were assessed for 5-hydroxymethyl tolterodine (5-HMT), the active moiety of fesoterodine.

RESULTS

Concomitant administration of fesoterodine with fluconazole increased AUC(0,∞) and C(max) of 5-HMT by approximately 27% and 19%, respectively, with corresponding 90% confidence intervals of (18%, 36%) and (11%, 28%). There was no apparent effect of fluconazole on 5-HMT t(max) or t(½) . Fesoterodine was generally well tolerated regardless of fluconazole co-administration, with no reports of death, serious adverse events (AEs) or severe AEs. Following co-administration of fesoterodine with fluconazole, 13 subjects (48%) experienced a total of 40 AEs; following administration of fesoterodine alone, six subjects (22%) experienced a total of 19 AEs. The majority of AEs were of mild intensity. There were no clinically significant changes in laboratory or physical examination parameters.

CONCLUSION

Fesoterodine 8 mg single dose was well tolerated when administered alone or with fluconazole. Based on the observed increase in 5-HMT exposures being within the inherent variability of 5-HMT pharmacokinetics, adjustment of fesoterodine dose is not warranted when co-administered with a moderate CYP3A4 inhibitor provided they are not also inhibitors of transporters.