Which of the following is a shoest acting benzodiazepine: September 2005
Ans. C: MidazolamA benzodiazepine can be placed into one of three groups by its elimination half-life, or time it takes for the body to eliminate half of the dose.Some benzodiazepines have long-acting active metabolites such as diazepam and chlordiazepoxide, which are metabolised into desmethyldiazepam. Desmethyldiazepam has a half-life of 36-200 hours.Very sho-acting compounds have a half-life of 2-5 hours.They have few residual effects if taken before bedtime, rebound insomnia may occur upon discontinuation and they might cause day time withdrawal symptoms such as next day rebound anxiety with prolonged usage.Examples are brotizolam, midazolam and triazolam.Sho-acting compounds have a half-life of 8-20 hours.They may have some residual effects in the first half of the day if used as a hypnotic.Rebound insomnia, however, is more common upon discontinuation of intermediate-acting benzodiazepines than longer acting benzodiazepines.Examples are estazolam, flunitrazepam, lormetazepam, nitrazepam and temazepam.Long-acting compounds have a half-life of 40-100 hours.They have a risk of accumulation in the elderly and in individuals with severely impaired liver function, but they have a reduced severity of rebound effects and withdrawal.Examples are diazepam and chlordiazepoxide.
Diazepam
Lorezepam
Midazolam
Alprazolam