Oxybutynin transdermal system

Oxybutynin transdermal system has similar efficacy but is better tolerated than oxybutynin IR presumably because this route avoids first-pass metabolism in the liver, which generates the metabolite thought to cause adverse events, especially dry mouth. 

Transdermal system - Following application of the first 3.9 mg/day transdermal system, oxybutynin plasma concentration increases for approximately 24 to 48 hours, reaching average maximum concentrations of 3 to 4 ng/mL. Thereafter, steady concentrations are maintained for up to 96 hours. Absorption of oxybutynin is bioequivalent when oxybutynin transdermal system is applied to the abdomen, buttocks, or hip. 

Hyoscyamine, Atropine, Scopolamine, Phenobarbital (Donnatal, Others) Methenamine (Hiprex, Urex, others) Nitrofurantoin (Macrodantin, Furadantin, Macrobid) Oxybutynin (Ditropan, Ditropan XL) Oxybutynin Transdermal System (Oxytrol) Pentosan Polysulfate (Elmiron) Phenazopyridine (Pyridium, others) Potassium Citrate (Urocit-K)... 

The oxybutynin transdermal system (Oxytrol), which delivers 3.9 mg per day, is applied twice weekly (every 3 or 4 days). Transdermal absorption of oxybutynin from this formulation bypasses first-pass hepatic and gut metabolism, resulting in similar oxybutynin bnt lower plasma A-desethyloxybutynin concentrations than after administration of an equivalent dose via the oral route. ° Similar findings have been noted for the active i -enantiomer of Af-desethyloxybntynin. No dosage adjustment of the TDS product for advancing age is necessary. ... 

Watson Pharma, Oxytrol (oxybutynin transdermal system) package insert. Morristown, NJ, 2003. 

OxYbutynin Transdermal System (Oxytrol) [GU Anrispasmodic/ Anhcholinergic] Uses Rx OAB Action Andcholineigic, relaxes bladder... 

Transdermal system 36 mg delivering 3.9 mg oxybutynin per day. Rx) Oxytrol (Watson)... 

Ditropan tablets 5 mg, syrup 5 mg/5 mL, Ditropan XL tablets, extended-release 5 mg, tablets, extended-release 10 mg, tablets, extended-release 15 mg, Oxytrol transdermal system 36 mg of oxybutynin delivering 3.9 mg or oxybutynin/day)... 

Overactive urinary bkuMer disease can be successfully treated with muscarinic antagonists, primarily tolterodine and trospium chloride, which lower intravesicular pressure, increase capacity, and reduce the frequency of contractions by antagonizing parasympathetic control of the bladder. Oxybu-tynin is used as a transdermal system (oxytrol) that delivers 3.9 mg/day and is associated with a lower incidence of side effects than the oral immediate- or extended-release formulations. Tolterodine is metabolized by CYP2D6 to a 5-hydroxymethyl metabolite since this metabolite possesses similar activity to the parent drug, variations in CYP2D6 levels do not affect the duration of drug action. Trospium is as effective as oxybutynin, with better tolerability. Solifenacin is newly approved for overactive bladder with a favorable efficacy side effect ratio. Stress urinary incontinence has been treated with some success with duloxetine (YENTREVE), which acts centrally to influence 5-HT and NE levels. 

Yu, Z. Gupta, S.K. Hwang, S.S. Cook, D.M. Duckett, M.J. Atkinson, L.E. Transdermal testosterone administration in hypogonadal men comparison of pharmacokinetics at different sites of application and at the first and fifth days of application. J. Clin. Pharmacol. 1997, 57, 1129-1138. Zobrist, R.H. Quan, D. Thomas, H.M. Stanworth, S. Sanders, S.W. Pharmacokinetics and metabolism of transdermal oxybutynin in vitro and in vivo performance of novel delivery system. Pharm. Res. 2003, 20, 103-109. Marzulli, E.N. Barriers to skin penetration. J. Invest. Dermatol. 1962, 39, 387-389. 

Zobrist, R.H., Quan, D., Thomas, H.M., Stanworth, S., and Sanders, S.W. (2003). Pharmacokinetics and metabolism of transdermal oxybutynin in vitro and in vivo performance of a novel delivery system. Pharmaceutical Research, 20, 103-109. 

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