fesoterodine fumarate

fesoterodine fumarate

Toviaz

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 C_max and area under the curve (AUC)

Rifampin: decreased active metabolite of fesoterodine C_max 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.