Atypical antipsychotic use for adult outpatients in New Zealand's Auckland and Northland regions.

AIM

To outline the prescribing patterns of atypical antipsychotics for adult mental health outpatients in Auckland and Northland in 2004.

METHODS

All community files were reviewed retrospectively (n = 6165). Patient characteristics, diagnosis, and antipsychotic and concurrent medication were recorded and analysed.

RESULTS

Overall, 71.3% of outpatients were prescribed an antipsychotic, of which 82.5% were atypicals: oral risperidone (30.9%), olanzapine (30.3%), quetiapine (17.1%), clozapine (26.3%), and depot risperidone (0.4%). Psychotic disorders accounted for 73.2% of outpatients on atypicals, and schizophrenia was the most common disorder overall (62.5%). Combination antipsychotic treatment occurred in 13.5% of those prescribed atypicals; 4.8% had another atypical and 8.7% had a typical co-prescribed. Clozapine was least likely to be combined with a typical antipsychotic. Those receiving combination typical and atypical antipsychotics had a greater likelihood of being prescribed an anticholinergic medication.

CONCLUSIONS

Atypical antipsychotics are the preferred treatment for outpatients with psychotic illness and are being prescribed in a manner consistent with clinical practice guidelines. Co-prescribing of antipsychotics was low, but may be causing unnecessary adverse effects and risks.