Flutoprazepam (Restas) is a drug which is a benzodiazepine. It was patented in Japan by Sumitomo in 1972 and its medical use remains mostly confined to that country. Its muscle relaxant properties are approximately equivalent to those of diazepam - however, it has more powerful sedative, hypnotic, anxiolytic and anticonvulsant effects and is around four times more potent by weight compared to diazepam. It is longer acting than diazepam due to its long-acting active metabolites, which contribute significantly to its effects.
Abuse of benzodiazepines in Japan is extremely common, with flutoprazepam, nimetazepam, temazepam and triazolam being the four most often sought after by drug users. Triazolam and temazepam make-up 65% of all prescription forgeries for benzodiazepines, while flutoprazepam and nimetazepam make up all the rest of the cases of benzodiazepine prescription forgeries. Diazepam and oxazepam are also commonly misused due to the fact that they are easily obtainable by prescription from doctors.
In Hong Kong, flutoprazepam is regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance. Flutoprazepam can only be used legally by health professionals and for university research purposes. The substance can be given by pharmacists under a prescription. Anyone who supplies the substance without prescription can be fined $10000 (HKD). The penalty for trafficking or manufacturing the substance is a $5,000,000 (HKD) fine and life imprisonment. Possession of the substance for consumption without license from the Department of Health is illegal with a $1,000,000 (HKD) fine and/or 7 years of jail time.
^US patent 3632574, Hisao Yamamoto et al, "PROCESS FOR PRODUCING BENZODIAZEPINE DERIVATIVES", published 1968-29-04, issued 1972-04-01
^Sukamoto, T.; Aikawa, K.; Itoh, K.; Nose, T. (Sep 1980). "[Psycopharmacological and general pharmacological studies of 7-chloro-1-cyclopropylmethyl-1, 3-dihydro-5-(2-fluorophenyl)-2H-1, 4-benzodiazepin-2-one (KB-509) (author's transl)]". Nippon Yakurigaku Zasshi76 (6): 447–68. doi:10.1254/fpj.76.447. PMID7203280.
^Ueki, S.; Sukamoto, T.; Watanabe, S.; Yamamoto, T.; Kataoka, Y.; Shibata, S.; Suwandi, D.; Shibata, K. et al. (Jul 1982). "[Behavioral effects of flutoprazepam (KB-509) and its metabolites]". Nippon Yakurigaku Zasshi80 (1): 15–30. doi:10.1254/fpj.80.15. PMID6890927.
^Barzaghi, N.; Leone, L.; Monteleone, M.; Tomasini, G.; Perucca, E. (1989). "Pharmacokinetics of flutoprazepam, a novel benzodiazepine drug, in normal subjects.". Eur J Drug Metab Pharmacokinet14 (4): 293–8. doi:10.1007/BF03190114. PMID2633923.
^Fukuda, T.; Itoh, K.; Nose, T. (Mar 1981). "[Antiulcerogenic action of 7-chloro-1-cyclopropylmethyl-1,3-dihydro-5-(2-fluorophenyl)-2H-1,4-benzodiazepin-2-one (KB-509), a new benzodiazepine derivative]". Nippon Yakurigaku Zasshi77 (3): 273–80. doi:10.1254/fpj.77.273. PMID7052359.