The pharmaco-economics of atypical antipsychotics.

Atypical antipsychotics are claimed to show advantages in efficacy and tolerability when compared with older, typical drugs. However, the purchase cost of atypicals far exceeds that of typical drugs. Pharmaco-economic evaluations of the use of atypical agents are used, in essence, to determine whether or not the benefit gained by using atypicals is greater than the extra cost of their acquisition. Several forms of pharmaco-economic evaluation have been developed, but none provides definitive, unarguable findings. In psychiatry, the most commonly used method is the mirror-image technique, which retrospectively compares costs and outcomes before and after the use of a particular drug. Despite the large number of phamacoeconomic evaluations undertaken and published, the cost-effectiveness of atypical drugs remains unproven. Data relating to clozapine are the most compelling, but they remain ultimately equivocal. However, ethical considerations may prevent conclusive research being conducted. Some data support the cost-effectiveness of olanzapine and risperidone, but, again, the overall picture is far from clear. Little or nothing is known of the pharmaco-economics of other atypicals. Further research is needed before any atypical can be said to be cost-effective.