Benzodiazepines are tranquillizers used to treat anxiety disorders (Low et al, 2000, 131-134). Benzodiazepine receptors are found throughout the central nervous system linked to gamma amino butyric acid (GABA) receptors, an inhibitory neurotransmitter in the CNS (Longo and Johnson, 2122). It enhances the affinity of the recognition site for GABA by inducing a conformational change. The GABA receptor complex also binds barbiturates and other sedative-hypnotics such as alcohol. Low et al have shown that they react with the alpha2-GABAA receptors, which are expressed mostly in the limbic system. They demonstrated the localization in two mouse lines, one of which had the alpha2 GABAA receptors obliterated and one of which had the alpha 3 GABAA receptors obliterated. The alpha3 GABAA receptors predominate in the reticular activating system. Benzodiazepines are widely prescribed for a variety of conditions, but particularly for anxiety and insomnia (Longo and Johnson, 2000, 2121). These drugs rapidly replaced barbiturates as sedative-hypnotic, and they cause significantly less respiratory depression than barbiturates so they are relatively safe, and even in cases of overdose, rarely result in death. However, they can be addicting when used chronically, and are often taken in combination with other drugs by patients with addiction disorders, so must be prescribed with care. Benzodiazepines act synergistically with other central nervous system depressants, including other hynotics, sedating antidepressants, neuroleptics, anticonvulsants, antihistamines, and alcohol. Benzodiazepines combined with alcohol or opiates can lead to a fatal overdose. Other drug interactions can occur: selective serotonin reuptake inhibitors (SSRIs) can increase the blood levels of diazepam and nefazadone (Serzone) can increase alprazolam levels as much as 10 times through hepatic enzyme inhibition, which leads to an increased sedative-hypnotic ef...