Which of the following statements regarding benzodiazepines is TRUE?

Barbiturates bind to GABA-BZD-Cl channel complex to exe GABA mimetic (direct activation of GABAA receptors) as well as GABA facilitatory actions. Benzodiazepines bind to a different site (BZD receptor) and increase the binding of GABA to GABAA receptor (GABA facilitatory action). These drugs increase the frequency of Cl- channel opening. Benzodiazepines are preferred over barbiturates as hypnotic drugs due to several reasons: BZDs have flat dose response curves (these have high therapeutic index and require high dose to produce coma). These cause less hangover and less distoion of sleep architecture. Duration of REM sleep is shoened but increase in the number of REM cycles compensate for that. Nitrazepam actually increases REM sleep. These are less prone to drug interactions (because they do not induce microsomal enzymes). Abuse liability is less. BZD poisoning can be treated with specific antidote, flumazenil.