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The effect of omeprazole on the bioavailability of sodium oxybate
Author(s) -
Borgen L. A.,
Morrison D.,
Lai A.
Publication year - 2004
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/j.clpt.2003.11.078
Subject(s) - cmax , omeprazole , medicine , pharmacokinetics , narcolepsy , proton pump inhibitor , crossover study , bioavailability , gastric emptying , pharmacology , anesthesia , placebo , stomach , modafinil , alternative medicine , pathology
Sodium oxybate is the only FDA‐approved treatment for cataplexy in narcolepsy. A high fat meal reduced C max by 59% and AUC by 37% (p<0.05). This randomized crossover study was conducted to determine if raising gastric pH with a proton pump inhibitor would alter the kinetics of oxybate. Healthy adults (n=44) were dosed on 2 occasions 14 days apart with a 3.0 g oral dose of sodium oxybate. Omeprazole (40 mg delayed‐release capsule) was administered for 5 days prior to oxybate on 1 of the 2 occasions. Serial plasma samples were collected up to 8 hours after each oxybate dose and frozen for subsequent oxybate analysis by a validated LC/MS/MS assay. Pharmacokinetic analysis yielded a ratio of least square geometric means (oxybate in the presence of omeprazole vs. oxybate by itself) of 0.89 for both C max and AUC with corresponding 90% confidence intervals falling within 0.80–1.25. Tmax and T1/2 were unchanged. Overall, the bioavailability of sodium oxybate was not significantly altered by omeprazole. The frequency and severity of adverse effects were also unaffected by the addition of omeprazole. Thus, the dosage of sodium oxybate does not require adjustment when given concomitantly with drugs that reduce gastric acidity. Clinical Pharmacology & Therapeutics (2004) 75 , P21–P21; doi: 10.1016/j.clpt.2003.11.078