fesoterodine fumarate
fesoterodine fumarate
Pharmacologic class: Competitive muscarinic receptor antagonist
Therapeutic class: Urinary tract agent
Pregnancy risk category C
Action
Inhibits muscarinic receptors, thereby inhibiting contraction of bladder smooth muscle
Availability
Tablets (extended-release): 4 mg, 8 mg
Indications and dosages
➣ Treatment of overactive bladder with symptoms of urge urinary incontinency, urgency, and frequency
Adults: 4 mg P.O. daily; may increase to 8 mg daily based on response and tolerability
Dosage adjustment
• Severe renal impairment (creatinine clearance of less than 30 ml/minute)
• Coadministration of potent CP3A4 inhibitors (such as clarithromycin, itraconazole, and ketoconazole; dosages above 4 mg not recommended)
Contraindications
• Hypersensitivity to drug or its components
• Urinary or gastric retention
• Uncontrolled narrow-angle glaucoma
Precautions
Use cautiously in:
• severe hepatic impairment (use not recommended)
• severe renal impairment, clinically significant bladder outlet obstruction
• decreased GI motility, such as with severe constipation
• concurrent treatment of narrow-angle glaucoma
• myasthenia gravis
• concurrent use of CYP3A4 inhibitors
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
• Administer with fluids and have patient swallow tablet whole.
Adverse reactions
CNS: insomnia
EENT: blurred vision, dry eyes, dry throat
GI: dry mouth, constipation, dyspepsia, nausea, upper abdominal pain
GU: urinary retention, urinary tract infection, dysuria
Musculoskeletal: back pain
Respiratory: cough, upper respiratory tract infection
Skin: decreased sweating, rash
Other: heat prostration, peripheral edema, angioedema
Interactions
Drug-drug. CP3A4 inhibitors (such as clarithromycin, itraconazole, ketoconazole): increased fesoterodine Cmax and area under the curve (AUC)
Rifampin: decreased active metabolite of fesoterodine Cmax and AUC
Other antimuscarinics: increased frequency or severity of adverse effects (such as dry mouth, constipation, urinary retention)
Drug-diagnostic tests. Alanine aminotransferase, gamma-glutamyltransferase: increased levels
Drug-behaviors. Alcohol use: increased drowsiness
Patient monitoring
• Monitor kidney and liver function tests closely.
☞ Be aware that life-threatening angioedema of the face, lips, tongue, and larynx has been reported with fesoterodine. In some cases, angioedema occurred after first dose. If involvement of the tongue, hypopharynx, or larynx occurs, promptly discontinue drug and initiate appropriate therapy and measures to ensure patent airway.
Patient teaching
• Instruct patient to take drug with fluids and to swallow tablet whole.
☞ Instruct patient to immediately stop drug and seek medical attention if difficulty breathing or swelling of the face, lips, or tongue occurs.
• Inform patient that drug may cause constipation and urinary retention.
• Caution patient to avoid driving and other hazardous activities until drug's effects on concentration and alertness are known.
• Advise patient to avoid excessive exercise in hot weather.
• Advise patient to avoid alcohol use while taking drug.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.