'As required' medication regimens for seriously mentally ill people in hospital

Drugs used to treat psychotic illnesses may take weeks to be effective. In the interim, additional 'as required' doses of medication can be used to calm patients in psychiatric wards. The practice is widespread with 20% - 50% of people on acute psychiatric wards receiving at least one 'as required' dose of psychotropic medication during their admission.

To compare the effects of 'as required' medication regimens with regular regimens of medication for the treatment of psychotic symptoms or behavioural disturbance, thought to be secondary to psychotic illness.

For this 2006 update, we searched The Cochrane Schizophrenia Group's register of trials (March 2006).

We included all relevant randomised control trials involving hospital inpatients with schizophrenia or schizophrenia-like illnesses, comparing any regimen of medication administered for the short term relief of behavioural disturbance, or psychotic symptoms, to be given at the discretion of ward staff ('as required', 'prn') with fixed non-discretionary patterns of drug administration of the same drug(s). This was in addition to regular psychotropic medication for the long-term treatment of schizophrenia or schizophrenia-like illnesses where prescribed.

We independently inspected abstracts, extracted data from the papers and quality assessed the data. For dichotomous data we would have calculated the relative risks (RR), with the 95% confidence intervals (CI) and the number needed to treat statistic (NNT). Analyses would have been conducted on an intention-to-treat basis.

We didn't identify any randomised trials comparing 'as required' medication regimens to regular regimens of the same drug.

There is no evidence from within randomised trials to support this common current practices. Current practice is based on clinical experience and habit rather than high quality evidence.