Prim Care Companion J Clin Psychiatry 2000;2(4):122-126
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Article Abstract
Objective: To test the hypothesis that reported in vitro muscarinic receptor affinity differences between olanzapine and risperidone would be reflected in peripheral solicited anticholinergic adverse event frequencies.
Results: Mean daily anticholinergic dose was significantly higher overall for the risperidone group (0.68 ± 1.27 mg) than for the olanzapine group (0.27 ± 0.76 mg) (p = .002). When only patients who did not receive anticholinergic adjunct therapy were considered, no significant differences in the frequency of specific anticholinergic adverse events occurred in olanzapine-treated patients as compared with risperidone-treated patients (p >= .245). There was also no significant difference between olanzapine and risperidone in the frequency of any anticholinergic adverse event (p = .458).
Conclusion: At clinically effective doses, olanzapine and risperidone did not differ significantly in frequency of peripheral anticholinergic events. These results support the view that, for olanzapine and risperidone, in vitro anticholinergic receptor binding (Ki values) may not predict in vivo peripheral events.