Determination of Dextrorphan in Plasma and Evaluation of Bioavailability of Dextromethorphan Hydrobromide in Humans

Effect of quinidine on the dextromethorphan O‐demethylase activity of microsomal fractions from human liver.

“…The values for total cytochrome P-450 content of the liver samples studied were similar to those reported in the literature when livers were obtained either post mortem (Souhaili-el Amri et al, 1986) or from kidney transplant donors shortly after circulatory arrest (Von Bahr et al, 1980;Meier et al, 1983) (Ramachander et al, 1977;Park et al, 1984;Barnhart & Massad, 1979;Schmid et al, 1985;Pfaff et al, 1983;Mascher, 1987;Motassin et al, 1987), but only Kronbach et al (1987) used h.p.l.c. to assay the in vitro production of dextrorphan by human liver microsomes.…”

Affinity and specificity of N-methyl-D-aspartate channel blockers affect their ability to disrupt prepulse inhibition of acoustic startle in rats

“…Dextromethorphan shows less consistent substitution; however, much of the variability may be associated with route of administration (Holtzman 1994). Dextromethorphan is metabolized to dextrorphan in humans and rats (Ramachander et al 1977;Schadel et al 1995;Wu et al 1995). In studies where dextromethorphan is administered via a route in which there is prominent first-pass metabolism, substitution consistently occurs and is probably related to conversion of dextromethorphan to dextrorphan (Holtzman 1994;Nicholson et al 1999).…”

Determination of dextromethorphan and its metabolite dextrorphan in human urine using high performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry: a study of selectivity of a tandem mass spectrometric assay

“…Dextrorphan (2), and levallorphan (3) (Fig. 1) were received from Research Biochemicals International (Natick, MA).…”

“…A number of methods have been described in the literature for the determination of 1 and 2 in urine including direct fluorescence spectrometry [2], high-performance liquid chromatography (HPLC) with fluorescence detection [3][4][5][6][7], HPLC with ultraviolet detection [8], and gas chromatography with flame ionization [9] and mass spectrometric detection [10]. In most of these methods, the limit of quantification of 1 was insufficient for the accurate determination of the 1/2 ratio.…”