Therapeutic Classification: urinary tract antispasmodics
Pharmacologic Classification: anticholinergics
Absorption: Rapidly absorbed following oral administration, but is rapidly converted to its active metabolite (bioavailability of metabolite 52%).
Distribution: Unknown.
Metabolism/Excretion: Primarily metabolized in the liver via the CYP2D6 and CYP3A4 isoenzymes; the CYP2D6 enzyme system exhibits genetic polymorphism; ∼7% of population may be poor metabolizers and may have significantly ↑ fesoterodine concentrations and an ↑ risk of adverse effects. 16% of active metabolite is excreted in urine, most of the remainder of inactive metabolites are renally excreted. 7% excreted in feces.
Half-Life: 7 hr (following oral administration).
(plasma concentrations of active metabolite)
| ROUTE | ONSET | PEAK | DURATION |
|---|
| PO | rapid | 5 hr | 24 hr |
Overactive Bladder
- PO (Adults ): 4 mg once daily initially; may ↑ to 8 mg/daily, if needed based on response and tolerability; Concurrent use of strong CYP3A4 inhibitors: Do not exceed 4 mg/day.
Renal Impairment
- PO (Adults ): CCr <30 mL/min: Do not exceed 4 mg/day.
Neurogenic Detrusor Overactivity
- PO (Children ≥6 yr and >35 kg): 4 mg once daily, then ↑ to 8 mg once daily after 1 wk; Concurrent use of strong CYP3A4 inhibitors: Do not exceed 4 mg/day.
- PO (Children ≥6 yr and 25–35 kg): 4 mg once daily; ↑ to 8 mg once daily, if needed; Concurrent use of strong CYP3A4 inhibitors: Use not recommended.
Renal Impairment
- PO (Children ≥6 yr and >35 kg): eGFR 15–29 mL/min/1.73 m2: Do not exceed 4 mg/day; eGFR <15 mL/min/1.73 m2 or requiring dialysis: Use not recommended
Renal Impairment
- PO (Children ≥6 yr and 25–35 kg): eGFR 30–89 mL/min/1.73 m2: Do not exceed 4 mg/day; eGFR <30 mL/min/1.73 m2 or requiring dialysis: Use not recommended
