Temazepam (Molecule of the Month for March 2009)
Normison, Temtabs, Euhypnos, Restoril, Remestan, Tenox, Norkotral
Temazepam is an intermediate-acting 3-hydroxy benzodiazepine. It is generally prescribed for the short-term treatment of sleeplessness in patients who have difficulty maintaining sleep. Temazepam is not effective for induction of sleep. In addition, temazepam has anxiolytic (anti-anxiety), anticonvulsant, and skeletal muscle relaxant properties.
Temazepam was first synthesized in 1964, but it first came into use in 1969 when its ability to counter insomnia was realized. By the late 1980s, temazepam was one of the most popular and widely prescribed hypnotics on the market and it became one of the most widely prescribed drugs. Temazepam is a hypnotic agent. In sleep laboratory studies, temazepam significantly decreased the number of nightly awakenings but has the drawback of distorting the normal sleep pattern. Temazepam is officially indicated for severe insomnia and other severe or disabling sleep disorders. The prescribing guidelines limit prescribing of hypnotics to two-to-four weeks due to concerns of tolerance and dependence.
Temazepam has the highest rate of drug intoxication, including overdose, among the common benzodiazepines. Temazepam and nitrazepam were the two benzodiazepines most commonly detected in overdose-related deaths in an Australian study of drug deaths. Temazepam is a drug with the potential for misuse. In 1987, Temazepam was the most widely-abused legal prescription drug in the United Kingdom. The use of benzodiazepines by street drug abusers was part of a polydrug abuse pattern, but many of those entering treatment facilities were declaring temazepam as their main drug of abuse. Temazepam was the most commonly used benzodiazepine in a study, published 1994, of injecting drug users in seven cities and had been injected from preparations of capsules, tablets and syrup. As a result in the United Kingdom, temazepam is a Class C controlled drug under the Misuse of Drugs Act 1971 (Schedule 3 under the Misuse of Drugs Regulations 2001). Temazepam is available only by a special controlled drug prescription form and requires special procedures in its storage and dispensing. Additionally, all manufacturers in the UK have replaced the gel-capsules with solid tablets. Temazepam prepared for injection is classed as a Class A drug. In the USA, temazepam is a Schedule IV drug and is only available by prescription. Specially coded prescriptions may be required in certain States.
Formal Chemical Name (IUPAC)
7-Chloro-1,3-dihydro- 3-hydroxy-1-methyl-5-phenyl- 1,4-benzodiazepin-2-one
Update by Karl Harrison
(Molecule of the Month for March 2009 )