tolterodine-tartrate and desethyloxybutynin

Overactive bladder is a dreadful syndrome that affects a considerable number of patients. Antimuscarinics are the mainstay of pharmacotherapy for this condition. Transdermal (TD) oxybutynin (OXY) bypasses the first-pass metabolism and reduces the formation of N-desethyloxybutynin, a compound believed to be associated with anticholinergic side effects. The 3.9 mg matrix TD system is applied twice weekly and transports OXY directly into the systemic circulation. The patch can be applied to abdomen, buttock, and hip, and provides continuous OXY delivery that minimizes peak and trough fluctuations in plasma levels. In clinical trials, TD and oral OXY produced a significant reduction in incontinence episodes, with no difference between oral and TD treatments. In addition, TDOXY was similar to tolterodine, and it produced a significant improvement in the number of urinary incontinence episodes, complete continence, and urodynamic and quality of life parameters compared with placebo. The incidence of anticholinergic adverse events with TDOXY was similar to placebo. Most common adverse events were mild-moderate skin reactions. Treatment satisfaction survey suggested patients' preference to use the TD system in the future. Counseling on healthy skin care and appropriate product use can enhance patients' knowledge about TDOXY for overactive bladder treatment.

Topics: Administration, Topical; Benzhydryl Compounds; Cresols; Humans; Mandelic Acids; Parasympatholytics; Patient Satisfaction; Phenylpropanolamine; Technology, Pharmaceutical; Tolterodine Tartrate; Urinary Bladder, Overactive

Oxybutynin binds to the M(3) muscarinic receptors on the detrusor muscle of the bladder, preventing acetylcholinergic activation and relaxing the muscle. The transdermal system delivers oxybutynin over a 3- to 4-day period after application to intact skin. Peak plasma concentrations of oxybutynin and the major active metabolite, N-desethyloxybutynin, are reached 24 - 48 hours after a single application and therapeutic concentrations are maintained throughout the dosage interval. In a large, randomised, double-blind trial, transdermal oxybutynin 3.9 mg/day significantly decreased the median number of incontinence episodes per week compared with placebo (-19 vs -15, p = 0.0165) in patients with overactive bladder. In addition, the micturition frequency was reduced and average voided volume was increased by transdermal oxybutynin treatment. Significant reductions in incontinence episodes following transdermal oxybutynin treatment were also observed in two further studies and the clinical efficacy was similar to that of oral tolterodine or oral oxybutynin. Transdermal oxybutynin was well tolerated in clinical trials. Application site reactions were the most common adverse effect; however, the majority were mild to moderate in severity. Adverse events associated with anticholinergic drugs (e.g. dry mouth) were less frequently reported in patients treated with transdermal oxybutynin than in those receiving orally administered oxybutynin or tolterodine.

Topics: Administration, Cutaneous; Administration, Oral; Adult; Aged; Benzhydryl Compounds; Cresols; Double-Blind Method; Exanthema; Humans; Mandelic Acids; Middle Aged; Phenylpropanolamine; Time Factors; Tolterodine Tartrate; Urinary Bladder Diseases; Urinary Incontinence; Xerostomia