Drug information of Fesoterodine

Mechanism of effect

Fesoterodine, once converted to its active metabolite, 5-hydroxymethyltolterodine, acts as a competitive antagonists at muscarinic receptors. This results in the inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder.

Pharmacodynamic

Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. Therefore, acting as a competitive muscarinic receptor antagonist, fesoterodine ultimately acts to decrease the detrusor pressure by its muscarinic antagonism, thereby decreasing bladder contraction and consequently, the urge to urinate.

Pharmacokinetics

Bioavailability: 52%

Protein Bound: 50%

Vd: 169 L (5-HMT active metabolite)

Metabolism: Rapidly hydrolyzed to active metabolite, and THEN by liver CYP3A4 and CYP2D6 to inactive metabolites

Half-Life: 7 hr

Excretion: Urine (70%); feces (7%)

Drug indications

overactive bladder

Dosage

Adult

Overactive Bladder

4 mg PO qDay; may increase 8 mg PO qDay based upon individual response and tolerability

Pediatric

Safety and efficacy not established

Drug contraindications

urinary retention , excessive sensitivity to the drug or its component , gastric retention

Side effects

Insomnia , nausea , dry mouth , Peripheral edema , Increased ALT , urinary retention , Rash , Xerophthalmia

Interactions

pilocarpine oral , Mibefradil , cobicistat , Delavirdine , Huperzine A , Itraconazole , Posaconazole , Voriconazole , Ketoconazole , Clarithromycin , Atazanavir , conivaptan , Telithromycin , boceprevir , Indinavir , Idelalisib , Telaprevir , Troleandomycin , Nefazodone , ritonavir , saquinavir , nelfinavir , Amprenavir , Fosamprenavir , glycopyrrolate topical , oleandomycin , Naltrexone and Bupropion , Gefitinib , Blonanserin

Alerts

Controlled narrow-angle glaucoma, bladder outflow obstruction, GI obstruction, reduced hepatic/renal function, and autonomic neuropathy

Angioedema of the face, lips, tongue, and/or larynx reported; in some cases angioedema occurred after the first dose

Anticholinergic CNS effects (eg, headache, dizziness, somnolence) reported; advise patients not to drive or operate heavy machinery until they adjust to therapy

Caution with myasthenia gravis, a disease characterized by decreased cholinergic activity at the neuromuscular junction, bladder flow obstruction

Heat prostration may occur in the presence of increased environmental temperature

Drug interactions overview

• Anticholinergic agents may potentially alter absorption of fesoterodine owing to decreased decreased GI motility
• Coadministration of potent CYP3A4 inhibitors ketoconazole with fesoterodine led to approximately a doubling of peak plasma concentration and area under the concentration versus time curve of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine
• Coadministration of moderate CYP3A4 inhibitors had no clinically relevant effect on the pharmacokinetics of fesoterodine
• Coadministration of rifampin 600 mg/day, a CYP3A4 inducer, Cmax and AUC of active metabolite of fesoterodine decreased by ~70% and 75% after fesoterodine 8 mg dose

Points of recommendation

• Tell all of your health care providers that you take fesoterodine. This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert or have clear eyesight until you see how fesoterodine affects you.
• Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
• Be careful in hot weather or while being active. Drink lots of fluids to stop fluid loss.
• A very bad reaction called angioedema has happened with fesoterodine. Sometimes, this may be life-threatening. Signs may include swelling of the hands, face, lips, eyes, tongue, or throat; trouble breathing; trouble swallowing; or unusual hoarseness. Get medical help right away if you have any of these signs.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using fesoterodine while you are pregnant.
• Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

• Take with or without food.
• Swallow whole. Do not chew, break, or crush.
• Take with a full glass of water.
• To gain the most benefit, do not miss doses.
• Keep taking fesoterodine as you have been told by your doctor or other health care provider, even if you feel well.

• Skip the missed dose and go back to your normal time.
• Do not take more than 1 dose of fesoterodine in the same day.

Related drugs

Oxybutynin , Darifenacin , Flavoxate , Trospium , Tolterodine , Solifenacin , Mirabegron