Impact of Legislative Changes on Patterns of Antipsychotic Prescribing and Self-Poisoning in Scotland: 2000-06

Abstract

-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.

Effects ofMHRAdrug safety advice on time trends in prescribing volume and indices of clinical toxicity for quinine

“…Specific changes to drug licences, however, may be needed in order to have a more substantial effect on prescribing with measurable benefits to public health. For example, reductions in prescribing and episodes of overdose followed restrictions to the indications for thioridazine in 2000 . As would be expected, substantial impact was demonstrated following the withdrawal of the licence for co‐proxamol in 2005, a preparation similar to quinine in terms of limited efficacy and profound toxicity in overdose.…”

Caffeine fatalities – Do sales restrictions prevent intentional intoxications?

“…One reason may be that caffeine tablets purchased before the sales restrictions were stored at peoples' homes. After legislative changes in the United Kingdom similar delays were seen, both concerning restriction of thioridazine in 2000 with zero cases of poisoning first in 2005-2006 and withdrawal of co-proxamol in 2004 where significant effects were not observed until 2006 18,19. …”

Comparative Drug Dose and Drug Combinations in Patients that Present to Hospital Due to Self‐Poisoning

“…For example, paracetamol (acetaminophen) is the commonest means of self-poisoning in the United Kingdom, the United States, Australia and elsewhere and is implicated in around 40% of emergency department presentations owing to overdose [5][6][7]. Other medications are highly represented owing to their prevalence in patients at high risk of self-harm, notably antidepressants, antipsychotic drugs and antiepileptic agents used as mood-stabilising agents [2,[8][9][10].…”