Two randomised controlled trials in this week's BMJ assess the effectiveness of different combinations of drugs for tranquillising and sedating people who are violent or agitated as a result of psychiatric disorders.1 2 Both trials were undertaken in developing countries.

The first trial, by Raveendran and colleagues, was carried out in the emergency services of a general psychiatry department in a hospital in South India. It compared the tranquillising and sedative effects of a single intramuscular administration of either olanzapine (10 mg) or a combination of haloperidol (10 mg) plus promethazine (50 mg) in 300 aggressive or agitated patients. The observation period lasted for four hours only and patients were followed up for just two weeks. This contrasts with most randomised controlled trials in psychiatry, which have treatment periods lasting for four to 12 weeks and can have several months of follow-up. The trial is important, however, because it looks at a neglected3 area—the early effects of treatment with parenteral antipsychotic drugs in patients who are violent or agitated. Without effective treatment these patients may harm themselves and their environment,3 and they are a heavy burden on resources in emergency psychiatry facilities.

Violent patients are usually psychotic and often receive antipsychotic …