Pharmacopsychiatry 2012; 45 - A15
DOI: 10.1055/s-0032-1326758

Rabbit syndrome and akathisia in a patient treated with risperidone

C Lay 1, C Spisla 1
  • 1Psychiatrische Dienste Aargau AG, EPD Ambulatorium Aarau, Aarau, Switzerland

Introduction: New generation (atypical) antipsychotics are associated with fewer extrapyramidal symptoms (EPS) than the conventional antipsychotics. Nevertheless, they can cause EPS such as akathisia and rabbit syndrome. Polypharmacy in psychiatric treatment can increase this risk. Case report: A 28 year old female with Obsessive Compulsive Disorder (OCD) developed under treatment with risperidone, quetiapine and venlafaxine EPS in terms of rabbit syndrom and akathisia. Biperiden did not reduce the symptoms at all. In order to avoid the risk of developing tardive dyskinesia and stigmatization, risperidone was discontinued. After stopping risperidone and replacement with higher dosage of quetiapine the symptoms disappeared. The symptoms of OCD were stable all the time. Drug plasma levels were not measured. Conclusion: This case shows that atypical antipsychotics can cause extrapyramidal symptoms such as rabbit syndrome and akathisia. These adverse symptoms should be recognized and appropriately treated. Biperiden was not effective, neither for rabbit syndrome nor for akathisia. Since EPS are drug concentration dependent, it would be important to measure drug plasma levels in case of such an unexpected ADR. Although a clinically relevant pharmacokinetic interaction seems unlikely, the patient could be a CYP2D6 poor metabolizer, which would lead to unexpectedly high plasma levels of risperidone and venlafaxine. Polypharmacy in this case increased the risk of EPS pharmacodynamically since the combination of two antipsychotics but also of antipsychotics with SSRI or SNRI increases this risk.