Antipsychotic-induced movement disorders in the elderly - Epidemiology andtreatment recommendations

We reviewed the epidemiological aspects of antipsychotic-induced movement d isorders as they pertain to older patients. The incidence and prevalence of drug-induced parkinsonism and tardive dyskinesia (TD) are significantly gr eater in the older patient than in the younger patient whereas akathisia se ems to occur evenly across the age spectrum and dystonia is uncommon among older patients. The literature on risk factors associated with treatment-em ergent movement disorders is highly variable. Treatment practices vary acro ss the age range and the interaction between age and antipsychotic dosage c onfounds our understanding of the relative importance of treatment-related risk factors. However, there is general agreement that pre-existing extrapy ramidal signs (EPS) increase the vulnerability of the patient to developing significant drug-induced movement disorders. Elderly patients with dementi a are at greater risk than patients without dementia for persistent drug-in duced EPS. Management of drug-induced movement disorders in the older patient requires careful consideration of the contraindications imposed by such agents as a nticholinergics and P-blockers. At present, well-controlled double-blind st udies of second-generation antipsychotics such as clozapine, risperidone, o lanzapine or quetiapine for reducing the risk of treatment-emergent movemen t disorders in the elderly have not been published. However, open-label stu dies of atypical antipsychotics demonstrate a markedly lower incidence of b oth EPS and TD compared with conventional antipsychotic treatment in the el derly. There is emerging literature in support of atypical antipsychotics f or the treatment of existing drug-induced movement disorders. More controve rsial is the use of adjunctive antioxidants in newly treated patients who a re vulnerable to drug-induced movement disorders. While the evidence is mix ed in support of antioxidants for the treatment of TD, the possibility rema ins that prophylactic use of antioxidants may help reduce the incidence of TD. The development of a drug-induced movement disorder often reduces the quali ty of life in an elderly patient. Effective pharmacological management requ ires cooperation from the patient and family, which can be fostered early i n the patient's care through proper informed consent. The risks and benefit s of antipsychotic treatment in the elderly patient need to be communicated to the patient and family. At the present time, there is no consistently e ffective treatment for patients with TD once it develops. Therefore, attent ion should focus on its prevention and close monitoring.