Fesoterodine Fumarate

In a rat model of spinal cord transection (T10), early oral administration of fesoterodine fumarate (FF) for 6 weeks significantly modulated detrusor overactivity. Compared to untreated spinal cord injured controls, FF at 0.12 mg/kg/day lowered intermicturition pressure, and both FF doses (0.12 and 0.18 mg/kg/day) reduced maximum pressure and threshold pressure. A 72‑hour washout after 6 weeks of treatment partially reversed some effects, indicating short‑term prevention. The authors conclude that early FF administration prevents bladder overactivity in this model, although long‑term efficacy needs further study, and clinical confirmation requires randomized trials.

Fig. 1 Representative cystometries, time scales used are the same in all 6 groups of animals (Groups 1–6). (Biardeau X, et al., 2017)

Population pharmacokinetic analysis of 5‑hydroxymethyl tolterodine (active metabolite of fesoterodine) in pediatric patients (≥6 years) with overactive bladder or neurogenic detrusor overactivity used a one‑compartment model with weight, sex, CYP2D6 status, and formulation as covariates. Simulations showed that fesoterodine 4 mg once daily for children weighing 25‑35 kg and 8 mg once daily for those >35 kg achieved exposures comparable to adults receiving 8 mg, producing a clinically meaningful increase in maximum cystometric capacity. Weight‑based dosing recommendations are provided.

Fig. 2 Relationship between observed MCC and predicted Cavg,ss for pediatric patients on fesoterodine 4 and 8 mg tablet QD or on fesoterodine 2 and 4 mg BIC QD in study 1047. (Sano Y, et al., 2023)