Anxiolytic — mexazolam
Patients with generalised anxiety disorder (GAD) suffer from anxiety, which is often severe, has no specific cause and continues for at least six months. It is believed to be a result of disturbance in the function of neurotransmitters such as GABA and noradrenaline within the brain, and affects around 2% of the population, with twice as many women developing the condition than men. Its symptoms include shaking, restlessness, fatigue, palpitations and light-headedness. Drugs used to treat GAD include the 5-HT1A receptor agonist buspirone and selective serotonin re-uptake inhibitors, but the benzodiazepines are the current drugs of choice for treatment over a limited period of time.
Problems seen with benzodiazepine therapy include sedation, the development of dependence, tolerance and failure of response. A benzodiazepine with reduced sedative effects that is being studied is mexazolam1. Structurally related to oxazolam, it has been shown to have potent anxiolytic activity.
In a multi-centre, double-blind randomised parallel-group comparison of mexazolam with the benzodiazepine drug alprazolam, 64 GAD patients were randomly assigned to treatment with one of the two drugs over a period of five weeks2. The starting dose of 1mg mexazolam or 0.5mg alprazolam three times a day was reduced according to clinical response. Mexazolam was found to have a similar activity profile to alprazolam, with its effect being sustained throughout the trial, including in the tapering-off and drug-free follow-up periods. No clinically-significant differences in tolerability were found between the two drugs. Side-effects were mild and consistent with those generally seen with benzodiazepines, with the most commonly seen being drowsiness. The trial has shown that mexazolam is an effective alternative drug treatment for GAD.