Aripiprazole,an antipsychotic having a novel dopamine D2 partial agonist mechanism of action was launched in Japan in June 2006.Since there is still not much experience of using this new drug in Japan,we decided to find out how doctors prescribe it and whether its prescription has been affecting chlorpromazine (CP) equivalent dosages of antipsychotics and concomitant use of anticholinergics by examining antipsychotic and anticholinergic prescriptions over 12 weeks for patients who were started on aripiprazole within 3 months of approval.We also sent a questionnaire to prescribers concerning their expectations of aripiprazole and the reasons if it had been discontinued.It was found that aripiprazole was much prescribed to patients receiving a single antipsychotic medication,and the most common expectation was further improvement of hallucinations and delusions.After the 12 weeks of the follow up,the prescription of aripiprazole increased the number of antipsychotics significantly but did not affect the CP equivalent dosage and percentage of concomitantly used anticholinergics.We found that the most common reason for discontinuation of aripiprazole was insufficient effectiveness for hallucinations and delusions,but in no patient was it withdrawn due to adverse effects.It seems that a complete switch to aripiprazole takes time even though it was prescribed to patients for whom switching was relatively easy,raising the possibility of polypharmacy and prolonged administration of anticholinergics.It is thus necessary to continuously monitor the administration of aripiprazole as well as that of other antipsychotics in order to prevent polypharmacy.
