Impact of legislative changes on patterns of antipsychotic prescribing and self-poisoning in Scotland: 2000-06

Recently, national guidelines have advocated greater use of atypical rather than typical antipsychotics in the treatment of schizophrenia. In addition, there have been safety concerns regarding the potential cardiotoxicity of certain antipsychotics taken in overdose. This has led regulatory authorities in the United Kingdom to restrict the use of thioridazine. The overall impact of these legislative changes on patterns of antipsychotic prescribing has received comparatively little attention. Therefore, we sought to examine the effects on community prescribing practices, and to determine whether this was accompanied by changes in patterns of antipsychotic poisoning. Between 2000-03, there was a rapid decline in the use of typical antipsychotics, whereas the use of atypical antipsychotics increased. The prevalence of atypical and typical antipsychotic prescribing has been approximately equal between 2003-06. During the same study period, hospital admissions due to typical antipsychotic poisoning also declined, however, the effects lagged behind changes in prescribing practice by 2-3 years. These data indicate that legislative changes that restrict the use of thioridazine and other typical antipsychotics are associated with a measurable reduction in the number of hospital admissions due to overdose with these agents.