N-Desalkylflurazepam has anelimination half-life of 47–150 hours[1] (up to 200 hours in some healthy volunteers),[3] with an average of ~71 hours.[2] Peak blood concentrations ofN-Desalkylflurazepam is reached at 10.2 h following a single 15 mg dose ofFlurazepam, typically around ~10-20.4 ng/mL.[2][3]
It's plasma levels are unreliable amongst patients, and are largely influenced by liver disease,liver enzyme inducers andinhibitors, as well as old age (in men).[3]
^abcNikfarjam Z, Doustkhahb E, Zamanic F, Brownd RW (August 2022). "Pharmaceutical applications of 1, 4-benzodiazepines".Benzodiazepine-Based Drug Discovery. pp. 125–182.doi:10.1016/B978-0-12-824516-3.00009-4.ISBN978-0-12-824516-3. p. 160:Table 5.19. Pharmacokinetic parameters of desalkylflurazepam as the major flurazepam metabolite after single 15 mg oral dose. Desalkylflurazepam shows the highest plasma peak concentration (20.4 ng/mL) that occurs at 10.2 h after dosing with an average t1/2 = 71.4 hr. This metabolite remains in the blood much longer than other species, which is still detectable after 9 days of administration.
^abcdeGreenblatt DJ, Abernethy DR, Divoll M, Harmatz JS, Shader RI (April 1983). "Pharmacokinetic properties of benzodiazepine hypnotics".Journal of Clinical Psychopharmacology.3 (2):129–132.doi:10.1097/00004714-198304000-00036.PMID6132931.
^Clarke GM, Barry LJ, Swinbourne FJ, Williamson B (1980). "The conversion of 2-(2-chloroacetamido)benzophenones into 2,3-dihydro-2-oxo-1,4-benzodiazepines. Part III. Further consideration of the hexamine system".Journal of Chemical Research, Synopses (12): 400.INISTPASCAL8130245432.
^Riva R, de Anna M, Albani F, Baruzzi A (March 1981). "Rapid quantitation of flurazepam and its major metabolite, N-desalkylflurazepam, in human plasma by gas-liquid chromatography with electron-capture detection".Journal of Chromatography.222 (3):491–495.doi:10.1016/S0378-4347(00)84153-5.PMID7228960.
^Barzaghi N, Leone L, Monteleone M, Tomasini G, Perucca E (1989). "Pharmacokinetics of flutoprazepam, a novel benzodiazepine drug, in normal subjects".European Journal of Drug Metabolism and Pharmacokinetics.14 (4):293–298.doi:10.1007/bf03190114.PMID2633923.
^Miyaguchi H, Kuwayama K, Tsujikawa K, Kanamori T, Iwata YT, Inoue H, et al. (February 2006). "A method for screening for various sedative-hypnotics in serum by liquid chromatography/single quadrupole mass spectrometry".Forensic Science International.157 (1):57–70.doi:10.1016/j.forsciint.2005.03.011.PMID15869852.
^abcNikaido AM, Ellinwood EH (1987). "Comparison of the effects of quazepam and triazolam on cognitive-neuromotor performance".Psychopharmacology.92 (4):459–464.doi:10.1007/bf00176478.PMID2888152.
^Ba BB, Iliadis A, Cano JP (1989). "Pharmacokinetic modeling of ethyl loflazepate (Victan) and its main active metabolites".Annals of Biomedical Engineering.17 (6):633–646.doi:10.1007/bf02367467.PMID2574017.
^Davi H, Guyonnet J, Necciari J, Cautreels W (July 1985). "Determination of circulating ethyl loflazepate metabolites in the baboon by radio-high-performance liquid chromatography with injection of crude plasma samples: comparison with solvent extraction and thin-layer chromatography".Journal of Chromatography.342 (1):159–165.doi:10.1016/S0378-4347(00)84498-9.PMID2864352.
