Economic consequences of the adverse reactions related with antipsychotics:: an economic model comparing tolerability of ziprasidone, olanzapine, risperidone, and haloperidol in Spain

Frequency of adverse reactions (ARs) related with antipsychotics usage is high. Along with clinical implications. economic impact Might be important. The purpose of this study was to model the economic consequences of ARs related with ziprasidone, olanzapine, risperidone, and haloperidol in Spain, by means of a cost-effectiveness model developed using a Markov modeling approach- The model sirntilaied treatment of a cohort of 1000 schizophrenics for 12 months, initiating treatment with one of four antipsychotic drugs; haloperiodol, risperidone, olanzapine and ziprasidone. Conditional probabilities of developing any of four adverse events were calculated. Treatment was modified (decrease dose, switch medication) according to incidence of ARs and physician judgments, obtained from a local cross-sectional study and clinical trials previously published. The analysis was conducted in year 2002 from a third party payer perspecitive. Results are shown as annual cost per month with psychotic symptoms controlled and included univariate sensitivity analysis. The therapeutic strategy starting with ziprasidone showed the lower costs and the greater number of months with symptoms controlled in most scenarios evaluated versus the other options considered, although the differences were weak: 9.6. 9.3: 9.5 and 9.5 controlled months per patient in base scenario. with annual cost per patient per month with symptoms controlled of euro1035, euro1084, euro1087 and euro1090 for ziprasidone. haloperidol. risperidone and olanzapine, respectively. Results were robust to one-way sensitivity analysis. Despite the unlike drug prices of antipsychotics, a considerable economic impact due to adverse reactions was seen in our setting. These results should be taken into account by health decision makers and clinicians in the management of patients with schizophrenia. (C) 2004 Elsevier Inc. All rights reserved.