Abstract
Neuroleptic-induced oculogyric crisis (OGC) is a dystonic reaction which usually occurs acutely after initiation of antipsychotic treatment. Among the atypical antipsychotics, cases of risperidone [1] and ziprasidoneinduced [2] acute OGC have been reported. However, a thorough search in September 2005 did not reveal any case of oculogyric crisis with olanzapine. We describe two adolescents who developed acute oculogyric crisis while on treatment with olanzapine.
A 14-year-old boy with normal birth and developmental history and a past history of depressive episode was brought to the outpatient department (OPD) with 5 days' history suggestive of a psychotic manic episode. He was started on tablet olanzapine 15 mg/day. In the very first week, the patient developed OGC characterized by 2–3 hour-long spells of tonic upward deviation of eyes with inability to look straight. Prophylactic oral trihexyphenidyl 2 mg/day was added in the follow-up and OGC did not recur.
A 17-year-old girl with nil contributory past history came to OPD with 2 months' history suggestive of psychotic manic episode. Treatment was initiated with Divalproex extended release tablets up to 750 mg/day and tablet olanzapine 10 mg/day. She developed OGC in the first week after initiating treatment which improved with injection promethazine 50 mg. On follow-up, olanzapine was decreased to 5 mg/day following which OGC did not recur.
The exact mechanism of neuroleptic-induced OGC is still unclear and possibly attributable to higher dopamine-acetylcholine antagonism [3] or higher striatal inhibition of dopamine function [4]. Although olanzapine has a receptor profile responsible for incidence of extrapyramidal side-effects at a rate comparable to that of placebo, its dopamine-acetylcholine antagonism and striatal dopamine blockade are higher than clozapine, which is a drug that does not induce acute dystonia.
Two important additional observations can be made from the cases. First, in both the occasions OGC responded well to common clinical interventions in the form of oral trihexyphenidyl, injection promethazine 50 mg, and dose reduction. Second, both of them were having manic episode with psychotic symptoms. Enhanced postsynaptic dopamine sensitivity [5] in bipolar patients could be a possible predisposing factor for neuroleptic-induced acute dystonia.
In short, this case report shows that even olanzapine can induce oculogyric crisis in predisposed individuals. However, the adverse effect is amenable to anticholinergic treatment or dose reduction.