Benzodiazepines: indications and side effects

Benzodiazepines: indications and side effects

     Benzodiazepines, such as Valium® for example, have long been the most widely used sleeping pills, these psychotropic drugs are actually anxiolytics that also have an effect on sleep disorders.

     Benzodiazepines owe their name to their common chemical structure: the benzodiazepine ring.

     This barbaric term is the chemical name for a cyclic structure that combines a benzene molecule (benzo-) and a molecule containing two nitrogen atoms (-diaz-).

     The names of the molecules in the benzodiazepine class (International Nonproprietary Names or INNs) all have the same suffix "-azepam".

Indications for benzodiazepines

     By binding to a specific receptor, benzodiazepines facilitate the action of a neurotransmitter, GABA (gamma-amino-butyric acid), on its receptor in the brain.

     GABA decreases the excitability of the central nervous system. This reduction will have several consequences illustrated by the many uses of benzodiazepines.


     Indeed, each benzodiazepine has several pharmacological actions in variable proportions: sedative, anxiolytic, anti-convulsant, and muscle relaxant.

     They will, therefore, be used to treat anxiety and insomnia of course, but also epilepsy and muscle contractures (torticollis, lumbago...).

     The sedative and hypnotic representatives are nitrazepam, estazolam, flunitrazepam, loprazolam, lormetazepam, temazepam, and triazolam.

     They have advantageously replaced barbiturates in the treatment of insomnia.

     Indeed, benzodiazepines are much less toxic in case of overdose (there is an antidote: flumazenil), less addictive, and do not cause the drug interactions of barbiturates.

     In addition, the residual daytime effects (drowsiness) are very weak. One benzodiazepine that has been widely prescribed in recent years as an anxiolytic (but also sometimes as a sleeping pill) is Lexomil® (bromazepam).

Side effects of benzodiazepines

     However, they are not a panacea and have significant side effects. Among these, anterograde amnesia is often pointed at and has earned flunitrazepam the sad reputation of "the rapist's drug".

     Feelings of drunkenness are also often sought by drug addicts in combination with alcohol.

     In addition, benzodiazepines are addictive when used for long periods or in high doses, resulting in a withdrawal syndrome and a rebound effect (i.e., a return of insomnia) when treatment is stopped.

     The end of treatment should, therefore, be gradual, with a steady reduction in dosage.

Contraindications

     In general, benzodiazepines are contraindicated in cases of respiratory failure, allergy to a benzodiazepine molecule, liver failure, sleep apnea, and myasthenia gravis.

Prescription-only

     Available only by prescription for several decades, the prescription conditions for all hypnotics were tightened by the government in the 1990s.

     The total duration of treatment should not exceed 8 to 12 weeks (3 for triazolam).

Benzodiazepine or "real" sleeping pill?

     Today, in the case of sleep disorders, benzodiazepines tend to be replaced by new related molecules classified as sleeping pills: zopiclone and zolpidem, for example.

     These derivatives are better tolerated than benzodiazepines, they do not alter REM sleep and pose fewer addiction problems.