Flunitrazepam metabolites

The metabolic deactivation offlunitrazepam illustrated in Fig. 8-20 proceeds via demethylation and hydroxylation to give desmethylflunitrazepam, an active metabolite, and 3-hydroxyflunitrazepam. However, these two compounds are only important in blood analysis. The main metabolite in the urine is the 7-amino-derivative, which is sometimes present as the acetamido-compound. 7-Aminodesmethylflunitrazepam and 3-hydroxy-7-acetamidoflunitrazepam are also relevant flunitrazepam metabolites in the urine, but the starting substance itself does not normally appear. Approximately 10% of the dose is excreted via the bile with the feces. 

Several studies have reported that alcohol increases plasma levels of diazepam and that alcohol accelerates the absorption of diazepam, but others have suggested that alcohol has no significant effect on diazepam pharmacokinetics. Plasma levels of brotizolam and clobazam may be increased by alcohol. One study reported that the plasma levels of triazolam were increased by alcohol, but other studies have found only a minimal pharmacokinetic interaction. However, an in vitro study demonstrated that alcohol inhibited the metabolism of triazolam by the cytochrome P450 isoenzyme CYP3A. Another in vitro study reported that the formation of flunitrazepam metabolites was weakly inhibited by alcohol, but a pharmacokinetic study suggested that there was no interaction. Alcohol appears to have minimal effects on the pharmacokinetics of alprazolam, and zopiclone. ... 

Note The detection limits for flunitrazepam and its 7-nitrodesmethyl metabolites are 1 to 2 ng/ml plasma or 0.5 ng substance per chromatogram zone. 

Diazepam and its nordiazepam, oxazepam, and temazepam metabolites are well retained by the MIP, while they are much less retained on NIP, also exhibiting large RSD. Other benzodiazepines of similar structures (Figure 1.50) were well retained on the MIP, showing that this template can be used for the general class of benzodiazepines. Two benzodiazepines studied, chlordiazepoxide and flunitrazepam, were poorly retained, indicating poor fit of these structures into the templated MIP. 

Lord et al. analyzed a mixture of steroids by CEC-ESI/MS and interfaced externally tapered CEC columns in both sheathless and sheath-flow arrangement. Sensitivity was found 20-fold higher in the sheathless configuration. The same conclusion was drawn by Warriner et ah, who evaluated CEC-nanospray/MS vs. CEC-microspray/MS with an ion trap using five corticosteroids. Cahours et al. used CEC-ESI/MS for a drug metabolism study and obtained a simultaneous baseline separation of flunitrazepam and its major metabolites. For CEC-ESI/MS coupling, the commercially available packed-CEC column was connected... 

Cahours, X., Cherkaoui, S., Rozing, G., and Veuthey, J. L. (2002). Microemulsion electrokinetic chromatography versus capillary electrochromatography-UV-mass spectrometry for the analysis of flunitrazepam and its major metabolites. Electrophoresis 23, 2320-2326. 

Eight BDZs among the most frequently encountered in forensic toxicology (clonazepam, desal-kylflurazepam, diazepam, flunitrazepam, lorazepam, midazolam, nordiazepam and oxazepam) were determined in whole blood after solvent extraction with butyl chloride and fast isocratic separation using a C18 (100 x 4.6 mm x 5 (tm) column [61]. The mobile phase was composed of phosphate buffer (35mM, pH 2.1) and acetonitrile (70 30, v/v) and the flow rate was 2mL/min. Within less than 4 min of analysis time, the analytes could be successfully determined starting from therapeutic concentrations. Using HPLC coupled with APCI-MS-MS, Rivera et al. [62] set up a method for the detection of 18 BDZ and metabolites after butyl chloride extraction at alkaline pH in 0.5mL... 

Those biotransformed by oxidative metabolism in the liver, primarily Ai-demethylation or hydroxylation (e.g., adinazolam, chlordiazepoxide, clobazam, diazepam, flunitrazepam, and medazepam), often yield pharmacologically active metabolites that must undergo further metabolic steps before excretion. 

More recently Wang et al. have proposed analytical methods involving the use of UHPLC-MS/MS to determine four opiates and metabolites, live amphetamines, flunitrazepam and its two metabolites, cocaine and its four metabolites in OF. Samples were collected by spitting in a tube, then the fluids were diluted with twice the amount of distilled and deionized water and vortexed for 30 s. Liquid chromatography was performed with a gradient elution and the total run time was 7.5 min. The authors compared ESI, APCI, and APPI. The ion suppression ranged from 45 to 89 % and from 74 to 96 % on APCI and APPI, respectively. The authors... 

Simultaneous Quantification of Flunitrazepam (Rohypnol) and its Major Metabolites in Human Plasma by Solid Phase Extraction and High-Performance Liquid Chromatography Atmospheric Pressure Chemical Ionization Tandem Mass Spectrometry, Using Deuterium Labeled Flunitrazepam as Internal Standard... 

The described assay is used for the simultaneous quantitative determination of the psychotropic drug flunitrazepam and its major metabolites (7-aminoflunitrazepam and N-desmethyl-flunitrazepam) in human plasma. 

Flunitrazepam and both metabolites were obtained from Promochem (Herts, UK). 

II.P.3 Simultaneous Quantification of Flunitrazepam (Rohypnol) and its Major Metabolites... 

Negrusz, A., et. al. Highly Sensitive Micro-Plate Enzyme Immunoassay Screening and NCI-GC-MS Confirmation of Flunitrazepam and Its Major Metabolite 7-Aminoflunitrazepam in Hair. Journal of Analytical Toxicology 23 (6) (1999) 429-435. 

Disposition in the Body. Readily absorbed after oral administration bioavailability 80 to 90%. The major metabolites are desmethylflunitrazepam and 7-aminoflunitrazepam which are active other metabolites include 3-hydroxyflunitrazepam, 3-hydroxy-7-acetamidoflunitrazepam, and 7-amino-1-desmethylflunitrazepam. Flunitrazepam is excreted in the urine almost entirely as metabolites with less than 1% as unchanged drug. About 10% of a dose is eliminated in the faeces. 

M. Kollroser, C. Schober, Simultaneous analysis of flunitrazepam and its major metabolites in human plasma by LC-MS-MS, J. Phaim. Biomed. Anal., 28 (2002) 1173. 

The detection of flunitrazepam (Rohypnol) is especially challenging because of the low therapeutic and illicit doses, and the low degree of cross-reactivity of most immunoassays with the principal urinary metabolite, 7-... 

Walshe K, Barrett AM, Kavanagh PV, McNamara SM, Moran C, Shattock AG. A sensitive immunoassay for flunitrazepam and metabolites. J Anal Toxicol 2000 24 296-9. 

Noggle, F.T., Jr. Clark, C.R. DeRuiter, J. Liquid chromatographic separation of some common benzodiazepines and their metabolites, J.Liq.Chromatogr., 1990, 13, 4005-4021 [also metabolites, alprazolam, bromazepam, chlordiazepoxide, clobazam, clonazepam, clorazepate, demoxepam, estazolam, fludiazepam, flunitrazepam, flurazepam, halazepam, lorazepam, midazolam, nitrazepam, nordiaze-pam, oxazepam, prazepam, temazepam, triazolam]... 

Thomare, R Wang, K. Van Der Meersch-Mougeot, V. Diquet, B. Sensitive micromethod for column liquid chromatographic determination of fluoxetine and norfluoxetine in human plasma. J.Chromatogr., 1992, 583, 217-221 [plasma extracted metabolites LOD 2 ng/mL simultaneous amineptine, amitriptyline, chlordiazepoxide, chlorpromazine, clomipramine, clonazepam, clorazepate, desipramine, diazepam, doxepin, flunitrazepam, fluvoxamine, imipramine, levomepromazine, loraze-pam, loxapine, maprotiline, mefloquine, nortriptyline, oxazepam, thioridazine]... 

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