Oxybutynin Omeprazole

In a placebo-controlled, crossover study in 39 healthy subjects, pre-treatment with omeprazole 20 mg daily for 4 days did not alter the pharmacokinetics of extended-release oxybutynin 10 mg [Ditropan XL], The metabolites of oxybutynin were similarly unaffected. Pretreatment with omeprazole increased the maximum plasma level a single 4-mg dose of extended release tolterodine [Detrol LA by 38%, but did not change any other pharmacokinetic parameter (time to maximum level, elimination half-life, AUC). ... 

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