Fesoterodine Fumarate

Class: Genitourinary Smooth Muscle Relaxants
ATC Class: G04BD11
VA Class: AU350
Chemical Name: isobutyric acid 2-((R)-3diisopropylammonium-1-phenylpropyl)-4-(hydroxymethyl) phenyl ester hydrogen fumarate
Molecular Formula: C₂₆H₃₇NO₃
CAS Number: 286930-03-8
Brands: Toviaz

Introduction

Genitourinary antispasmodic; an antimuscarinic agent.^{1 2 3 4 6}

Uses for Fesoterodine Fumarate

Overactive Bladder

Relief of symptoms associated with voiding (e.g., urge urinary incontinence, urgency, frequency).^{1 2 3 4 6 11}

Fesoterodine Fumarate Dosage and Administration

Administration

Oral Administration

Administer orally once daily with liquids without regard to meals.^{1 5}

Swallow extended-release tablets whole; do not chew, divide, or crush.^{1 5}

Dosage

Available as fesoterodine fumarate; dosage expressed in terms of the salt.¹

Adults

Overactive Bladder

Oral

Initially, 4 mg once daily.¹ Depending on individual response and tolerability, may increase to 8 mg once daily.¹

Prescribing Limits

Adults

Overactive Bladder

Oral

Maximum 8 mg daily.¹

Special Populations

Hepatic Impairment

Manufacturer does not recommend dosage adjustments for patient with mild or moderate hepatic impairment.¹ Some clinicians recommend caution when increasing dosage from 4 mg to 8 mg daily in patients with mild hepatic impairment (Child-Pugh class A) and a maximum dosage of 4 mg daily in patients with moderate hepatic impairment (Child-Pugh class B).^{2 10} (See Absorption: Special Populations, under Pharmacokinetics.)

Use not recommended in patients with severe hepatic impairment (Child-Pugh class C).^{1 10}

Renal Impairment

Manufacturer does not recommend dosage adjustments for patient with mild or moderate renal impairment (Cl_cr 30–80 mL/minute); some clinicians recommend caution when increasing dosage from 4 mg to 8 mg daily in such patients.^{1 2 10} (See Absorption: Special Populations, under Pharmacokinetics.)

In patients with severe renal impairment (Cl_cr <30 mL/minute), maximum dosage 4 mg daily.^{1 10}

Geriatric Patients

No dosage adjustment required.¹

Cautions for Fesoterodine Fumarate

Contraindications

• 
  

  Urinary retention, gastric retention, or uncontrolled angle-closure glaucoma.¹

  
  


• 
  

  Known hypersensitivity to fesoterodine fumarate or any ingredient in the formulation.¹

  
  

Warnings/Precautions

General Precautions

Urinary Retention

Risk of urinary retention; use with caution in patients with clinically important bladder outflow obstruction.¹

Decreased GI Motility

Use with caution in patients with decreased GI motility (e.g., patients with severe constipation).¹

Controlled Angle-closure Glaucoma

Use with caution in patients being treated for angle-closure glaucoma and only when potential benefits outweigh risks.¹ (See Cautions: Contraindications.)

Myasthenia Gravis

Use with caution in patients with myasthenia gravis.¹

Specific Populations

Pregnancy

Category C.¹

Lactation

Not known whether fesoterodine is distributed into milk in humans; do not use unless benefit to woman outweighs potential risk to the infant.¹

Pediatric Use

Safety and efficacy not established in pediatric patients.¹

Geriatric Use

No substantial differences in safety and efficacy relative to younger adults.¹

Incidence of adverse antimuscarinic events (e.g., dry mouth, constipation, dyspepsia, increase in residual urine, dizziness [only at a dosage of 8 mg daily]) and urinary tract infection was higher in patients ≥75 years of age compared with younger patients.¹

Hepatic Impairment

Not studied in patients with severe hepatic impairment (Child-Pugh class C); use not recommended in these patients.¹ (See Hepatic Impairment under Dosage and Administration.)

Renal Impairment

Dosage adjustment recommended in patients with severe renal impairment.¹ (See Renal Impairment under Dosage and Administration.)

Common Adverse Effects

Dry mouth, constipation.^{1 9}

Interactions for Fesoterodine Fumarate

Rapidly metabolized to active metabolite, 5-hydroxymethyl tolterodine (5-HMT), by nonspecific esterases; active metabolite is further metabolized, principally via CYP2D6 and CYP3A4.^{1 2 10} 5-HMT does not inhibit CYP isoenzymes 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, or 3A4 and does not induce CYP isoenzymes 1A2, 2B6, 2C9, 2C19, or 3A4.¹

Drugs Affecting Hepatic Microsomal Enzymes

Potent inhibitors of CYP3A4: Potential pharmacokinetic interaction (increased plasma 5-HMT concentrations).¹ Do not exceed 4 mg daily when used concomitantly with potent CYP3A4 inhibitors.¹

Weak or moderate inhibitors of CYP3A4: Effects on 5-HMT pharmacokinetics not studied; pharmacokinetic interaction is expected, albeit less than that observed with potent CYP3A4 inhibitors.¹ Carefully assess tolerability at 4-mg daily dosage of fesoterodine fumarate prior to increasing dosage to 8 mg daily in patients concomitantly receiving weak or moderate CYP3A4 inhibitors.¹

Inducers of CYP3A4: Potential pharmacokinetic interaction (decreased plasma 5-HMT concentrations); no dosage adjustments are recommended.¹

Inhibitors of CYP2D6: Effects on 5-HMT pharmacokinetics not tested clinically.¹ However, increased plasma 5-HMT concentrations observed in subjects with poor metabolizer phenotype for CYP2D6; no dosage adjustments recommended when CYP2D6 inhibitors are used concomitantly.¹

Drugs Metabolized by Hepatic Microsomal Enzymes

Substrates of CYP1isoenzymeA2 s, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, or 3A4: Pharmacokinetic interactions unlikely.¹

Orally Administered Drugs

Potential pharmacokinetic interaction (altered absorption because of anticholinergic effects on GI motility).¹ (See Decreased GI Motility under Cautions.)

Specific Drugs

Drug	Interaction	Comments
Antimuscarinic agents	Potential increased frequency and/or severity of adverse anticholinergic effects (e.g., dry mouth, constipation, urinary retention) 1
Azole antifungals (itraconazole, ketoconazole)	Possible increased plasma 5-HMT concentrations1 Ketoconazole: Increased plasma 5-HMT concentrations1	Do not exceed a fesoterodine fumarate dosage of 4 mg daily when used concomitantly1
Clarithromycin	Possible increased plasma 5-HMT concentrations1	Do not exceed a fesoterodine fumarate dosage of 4 mg daily when used concomitantly1
Hormonal contraceptives, oral (ethinyl estradiol-levonorgestrel)	Pharmacokinetic interaction unlikely1
Erythromycin	Effects on 5-HMT pharmacokinetics not studied; pharmacokinetic interaction is expected1	Carefully assess tolerability at fesoterodine fumarate 4-mg daily dosage prior to increasing dosage to 8 mg daily1
Rifampin	Decreased plasma 5-HMT concentrations and AUC1	No fesoterodine fumarate dosage adjustments recommended1

Fesoterodine Fumarate Pharmacokinetics

Absorption

Bioavailability

Following oral administration of fesoterodine, peak plasma concentrations of active metabolite, 5-hydroxymethyl tolterodine (5-HMT), are achieved in approximately 5 hours; because of rapid metabolism, fesoterodine itself is not detected in plasma.¹

Bioavailability of 5-HMT is 52%.¹

Onset

Symptomatic improvement (i.e., reduction in number of urge incontinence episodes) observed as early as 2 weeks after starting fesoterodine therapy.¹

Food

Food has no clinically important effect on fesoterodine pharmacokinetics.¹

Special Populations

In individuals with poor metabolizer phenotypes of CYP2D6 (approximately 7% of Caucasians and 2% of African Americans), peak plasma concentrations of 5-HMT increased by 1.7-fold and AUC increased twofold as compared with extensive metabolizers.¹

In patients with mild or moderate renal insufficiency (Cl_cr 30–80 mL/minute), peak plasma concentrations and AUC of 5-HMT were increased up to 1.5- and 1.8-fold, respectively, as compared with those in healthy subjects.¹ In patients with severe renal impairment (Cl_cr <30 mL/minute), peak plasma concentrations and AUC of 5-HMT were increased twofold and 2.3-fold, respectively.¹ (See Renal Impairment under Dosage and Administration.)

In patients with moderate (Child-Pugh class B) hepatic impairment, peak plasma concentrations and AUC of 5-HMT were increased 1.4 and 2.1-fold, respectively, as compared with those in healthy subjects.¹ Subjects with severe hepatic impairment (Child-Pugh class C) have not been studied.¹ (See Hepatic Impairment under Dosage and Administration.)

Distribution

Extent

Not known whether distributed into human milk.¹

Plasma Protein Binding

5-HMT: Approximately 50%, principally to albumin and α₁-acid glycoprotein.¹

Elimination

Metabolism

Fesoterodine is a prodrug: rapidly and extensively hydrolyzed by nonspecific esterases to 5-HMT, which is responsible for the antimuscarinic effects of fesoterodine.^{1 2 6 10} Tolterodine, another antimuscarinic agent used in the treatment of overactive bladder, also is metabolized to 5-HMT; however, tolterodine metabolism to 5-HMT is via CYP2D6.^{1 2 10}

5-HMT is further metabolized to various metabolites in the liver, principally via CYP2D6 and CYP3A4.^{1 2 6 10} None of these metabolites contribute substantially to the antimuscarinic activity of fesoterodine.^{1 10}

Elimination Route

Recovered in urine (70%) and feces (7%) as various active and inactive metabolites.^{1 6}

Half-life

Terminal half-life of 5-HMT following oral administration of fesoterodine fumarate is approximately 7 hours.^{1 2 10}

Special Populations

Pharmacokinetics not substantially affected by gender or age; pharmacokinetics not studied in pediatric patients.¹

Available data indicate no differences in pharmacokinetics between Caucasian and black subjects.¹

Stability

Storage

Oral

Tablets

20–25°C (may be exposed to 15–30°C).¹ Protect from moisture.¹

ActionsActions

• 
  

  Fesoterodine is a competitive antimuscarinic agent.¹

  
  


• 
  

  Fesoterodine is a prodrug: rapidly and extensively hydrolyzed to 5-hydroxymethyl tolterodine (5-HMT), which is responsible for the antimuscarinic effects of fesoterodine.^{1 2 6 10}

  
  


• 
  

  Fesoterodine and 5-HMT inhibit contraction of the urinary bladder smooth muscle.^{1 6}

  
  


• 
  

  In urodynamic study, fesoterodine administration increased volume at first detrusor contraction and bladder capacity in dose-dependent manner.¹

  
  

Advice to Patients

• 
  

  Importance of reading manufacturer's patient information before beginning fesoterodine therapy.^{1 5}

  
  


• 
  

  Risk of dry mouth, constipation, dry eyes, urinary retention, decreased sweating and heat prostration (when used in a hot environment).^{1 5}

  
  


• 
  

  May cause blurred vision and drowsiness.^{1 5} Use caution when driving or performing dangerous activities until effects are known.⁵ Alcohol may enhance the drowsiness caused by fesoterodine.^{1 5}

  
  


• 
  

  Importance of taking fesoterodine with liquids and swallowing the extended-release tablet whole; do not chew, divide, or crush.^{1 5}

  
  


• 
  

  Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.^{1 5}

  
  


• 
  

  Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses.^{1 5}

  
  


• 
  

  Importance of advising patients of other important precautionary information.¹ (See Cautions.)

  
  

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Fesoterodine Fumarate

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Tablets, extended-release	4 mg	Toviaz	Pfizer
		8 mg	Toviaz	Pfizer

Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. and Drugs.com represent that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. and Drugs.com make no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. and Drugs.com do not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS Drug Information. © Copyright, 1959-2011, Selected Revisions February 2010. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

References

1. Pfizer. Toviaz (fesoterodine fumarate) extended-release tablets prescribing information. NY, NY; 2008 Nov.

2. Michel MC. Fesoterodine: a novel muscarinic receptor antagonist for the treatment of overactive bladder syndrome. Expert Opin Pharmacother. 2008; 9:1787-96. [PubMed 18570610]

3. Nitti VW, Dmochowski R, Sand PK et al. Efficacy, safety and tolerability of fesoterodine for overactive bladder syndrome. J Urol. 2007; 178:2488-94. [PubMed 17937959]

4. Chapple C, Van Kerrebroeck P, Tubaro A et al. Clinical efficacy, safety, and tolerability of once-daily fesoterodine in subjects with overactive bladder. Eur Urol. 2007; 52:1204-12. [PubMed 17651893]

5. Pfizer. Toviaz (fesoterodine fumarate) extended-release tablets patient information. NY, NY; 2008 Nov.

6. McKeage K, Keating GM. Fesoterodine. Drugs. 2009; 69:731-8. [PubMed 19405552]

7. Kelleher CJ, Tubaro A, Wang JT et al. Impact of fesoterodine on quality of life: pooled data from two randomized trials. BJU Int. 2008; 102:56-61. [PubMed 18564231]

8. Chapple C, Van Kerrebroeck P, Tubaro A et al. Clinical efficacy, safety, and tolerability of once-daily fesoterodine in subjects with overactive bladder. Eur Urol. 2007; 52:1204-12. [PubMed 17651893]

9. Khullar V, Rovner ES, Dmochowski R et al. Fesoterodine dose response in subjects with overactive bladder syndrome. Urology. 2008; 71:839-43. [PubMed 18342923]

10. Witte LP, Mulder WM, de la Rosette JJ et al. Muscarinic receptor antagonists for overactive bladder treatment: does one fit all?. Curr Opin Urol. 2009; 19:13-9. [PubMed 19057211]

11. Chapple CR, Khullar V, Gabriel Z et al. The effects of antimuscarinic treatments in overactive bladder: an update of a systematic review and meta-analysis. Eur Urol. 2008; 54:543-62. [PubMed 18599186]

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