Are specific initiatives required to enhance prescribing of generic atypical antipsychotics in Scotland?: International implications

Background: National and regional authorities in Scotland have introduced multiple measures to appreciably enhance prescribing efficiency for the proton pump inhibitors (PPIs), statins and renin-angiotensin inhibitor drugs. Generic oral risperidone recently became available in Scotland; however, schizophrenia is a complex disease with advice from respected authorities suggesting that treatment should be individualised.

Aims: To assess (i) changes in atypical antipsychotic drug (AAP) utilisation and expenditure following the availability of oral generic risperidone in Scotland; (ii) to determine (a) current INN prescribing rates for risperidone following generic availability and (b) decrease in expenditure/DDD for generic risperidone; (iii) to suggest additional measures that could possibly be introduced in Scotland to further enhance prescribing of generic AAPs; and (iv) to provide guidance to NHS Scotland as well as other European authorities on the implications.

Methods: Retrospective observational study and an interrupted time series design.

Results: No appreciable change in the utilisation patterns of risperidone pre- and postgeneric availability. Appreciable INN prescribing averaged 93-98% of total oral risperidone. Generic risperidone was 84% below prepatent loss prices by study end, reducing annual expenditure for oral risperidone in 2010 by GB£3.19mn compared with prepatent loss situation. However, overall expenditure on AAPs increased by 42% from 2005 to 2010.

Discussion: As expected, there was no change in utilisation patterns for risperidone, although potential to influence prescribing patterns. Continued high INN prescribing suggests no problems with generic risperidone in practice. Costs will start to decrease as more AAPs lose their patents (olanzapine and quetiapine). There is the possibility to accelerate this reduction through educational activities.

Conclusion: There is potential to realise some savings with generic AAPs. However, this is limited by the complexity of the disease area. Any measures introduced must aim at increasing the prescribing of generic AAPs first line in suitable patients.