Aripiprazole-induced rabbit syndrome

Clozapine-induced rabbit syndrome: a case report

Rabbit syndrome (RS) is an antipsychotic-induced rhythmic motion of the mouth/lips resembling the chewing movements of a rabbit. The movement consists of a vertical-only motion, at about 5 Hz, with no involvement of the tongue. Long-term exposure to typical antipsychotics has clearly been associated with RS, but little is known of the risk of RS due to exposure to newer atypical antipsychotics. There have been isolated reports of RS in patients treated with the atypical agents risperidone, aripiprazole, olanzapine, and clozapine. We present the case history of a 44-year old female patient treated for paranoid schizophrenia for 22 years and RS during her last 10-month clozapine treatment. Background information from the literature is also discussed.

Newer antipsychotics and the rabbit syndrome

BACKGROUND

Rabbit syndrome is a movement disorder that is associated with long-term exposure to neuroleptic medications. Of particular interest and importance is the risk of rabbit syndrome with exposure to the newer atypical antipsychotics. Our recent experience with such a case brought to light the importance of exploring this risk.

METHODS

MEDLINE and PubMed (1972-2006) databases were searched for English language articles using the keywords rabbit syndrome, tardive dyskinesia, antipsychotic, extrapyramidal symptoms and side effects. A recent case study is used to expand upon the literature available on newer antipsychotics and rabbit syndrome.

RESULTS

We reviewed papers that addressed the following aspects of rabbit syndrome 1) the clinical manifestations 2) prevalence and risk factors, 3) etiopathogenesis 4) older antipsychotics and rabbit syndrome 5) newer antipsychotics, 6) treatment options. Moreover, we report a case of RS in a 50 year old white female, diagnosed with bipolar I disorder, that, after the discontinuation of risperidone, developed involuntary movements of the mouth that were fine, rhythmic and rapid, along the vertical axis, and without involvement of the tongue. After the re-introduction of risperidone, the symptoms decreased in a few hours and disappeared after 3 days.

CONCLUSION

Eleven cases of rabbit syndrome have been documented since the implementation of newer antipsychotics. Future research is needed to better understand the etiopathogenesis of rabbit syndrome in psychiatric populations treated with the atypical antipsychotics. Understanding the differences and similarities of rabbit syndrome and tardive dyskinesia is crucial to the creation of a successful treatment paradigm.

Potential aripiprazole-mediated extrapyramidal symptoms in an adult with developmental disabilities

PURPOSE

A case of extrapyramidal symptoms (EPS) following administration of aripiprazole to a man with developmental disabilities who had never received antipsychotic medications and had no history of movement disorders is presented.

SUMMARY

The patient was a 40-year-old male with developmental disabilities. He was nonverbal, profoundly mentally retarded, and diagnosed with obsessive compulsive disorder (OCD) and orthopedic problems. He developed episodic movements possibly consistent with EPS secondary to aripiprazole usage. The patient was antipsychotic naive before initiation of aripiprazole 5 mg daily. Concurrent medications at the time of EPS onset included oxazepam, baclofen, and citalopram. Baclofen and oxazepam were prescribed secondary to right-sided hemiparesis contractures. Aripiprazole, 5 mg daily, was initiated in November 2004 as an augmentation strategy for the diagnosis of OCD. Facial, tongue, and arm movements were first reported approximately five weeks after the initiation of aripiprazole. Initial symptoms resolved after approximately 24 hours. The dosage was increased to 10 mg daily two weeks later. Dystonic episodes continued on an intermittent basis, and the patient presented with lower-lip thrusting and upper-limb athetosis. These movements interfered with the patient's eating, chewing, and holding of utensils. Several of the standard treatment strategies for EPS were used. Initially, diphenhydramine hydrochloride 25 mg was administered orally every six hours. The patient's movements resolved following diphenhydramine administration. Aripiprazole was subsequently discontinued secondary to its lack of efficacy for OCD and the development of a movement disorder.

CONCLUSION

A patient with developmental disabilities who had no history of movement disorders developed EPS following initiation of aripiprazole.

Aripiprazole in the acute treatment of male patients with schizophrenia: effectiveness, acceptability, and risks in the inner-city hospital setting

Aripiprazole, a novel atypical antipsychotic that acts as a partial agonist at the dopamine D(2) receptors, has been reported to be effective in the treatment of chronic schizophrenia. However, the risks and benefits of using aripiprazole in the acute hospital setting to treat severe psychotic disorders are unclear. This naturalistic study assessed the effectiveness of aripiprazole monotherapy in a group of actively psychotic male patients (n = 10) with schizophrenia who were admitted to an inner-city acute psychiatric unit. Most patients (n = 7) responded to aripiprazole treatment, which was well tolerated and significantly ameliorated psychotic symptoms after 2-3 weeks. Patients who responded to it could be safely discharged on aripiprazole monotherapy. Side effects observed were mostly mild and transient, and included extrapyramidal symptoms (n = 1) and neutropenia (n = 1). Aripiprazole also remarkably attenuated dyskinetic movements in 1 patient with severe tardive dyskinesia, thereby suggesting that it may be useful in the treatment of other disorders that are also associated with dopamine dysfunction. Results showed that aripiprazole can be safely and effectively employed in the hospital setting to treat severely psychotic patients with schizophrenia, but further studies are required to establish the full range of adverse reactions and therapeutic indications associated with its use.