Detail of "5965-13-9"

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Pharmacokinetics of intravenous and oral dihydrocodeine and its acid metabolites

Pharmacokinetics of intravenous and oral dihydrocodeine and its acid metabolites. Rowell, F. J.; Seymour, R. A.; Rawlins, M. D. (Dep. Pharm. 70001-26-2 and 5965-13-9 are also occured in this study. Chem., Sunderland Polytech., Sunderland, UK). Eur. J. Clin. Pharmacol., 25(3), 419-24 (English) 1983. CODEN: EJCPAS. ISSN: 0031-6970. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Serum concns. of dihydrocodeine [125-28-0] and its acid metabolites were detd. in 7 human volunteers (6 male ) who received the drug (dihydrocodeine bitartrate [5965-13-9]) orally (30 mg and 60 mg) and i.v. (30 mg) on sep. occasions, and in 24 patients (12 male receiving 25 mg or 20 mg of the drug i.v. The concns. were estd. by radioimmunoassay on reconstituted exts. from serum after an extn. process which effectively separates dihydrocodeine from its polar acidic metabolites. The i.v. data show that dihydrocodeine kinetics followed a 2-compartment distribution model. The concn. curves after oral administration indicated relatively rapid absorption with mean peak concns. at 1.6 h - 1.8 h. The mean half-liver varied between 3.3 h-4.5 h. From the area under the plasma concn. time curve, the mean bioavailability of orally administered drug was 21% (range 12-34%). The peak levels of the acid metabolites occurred between 1.8 h-2.0 h after oral administration and 2.2 h - 2.5 h after i.v. administration, and they were significantly greater after oral administration. The low bioavailability of dihydrocodeine, together with the earlier and higher plasma levels of the acid metabolites after oral administration is suggestive of substantial first-pass metab. .