Neurological Complications of Antipsychotic Drugs

This chapter reviews the main neurological complications of antipsychotics drugs. Extrapyramidal syndromes include acute dystonia, parkinsonism, akathisia, and tardive dyskinesia. These syndromes are less frequent with atypical drugs compared to haloperidol. Some, but not all, atypicals also show an EPS advantage when compared to low-potency conventional drugs. Neuroleptic malignant syndrome (NMS) consists of muscle rigidity, pyrexia, change in conscious level, and autonomic disturbance, but partial forms also occur. Most reported cases of NMS have occurred soon after starting haloperidol, but the syndrome can occur with all antipsychotics and less frequently with other psychiatric drugs. The risk of seizures with antipsychotics is dose related. Clozapine and zotepine are the most epileptogenic of the atypical drugs and chlorpromazine the most epileptogenic of the conventional drugs. Both atypical and conventional antipsychotics appear to increase the risk of stroke and death in elderly patients with dementia, though the underlying mechanism remains unclear. Clinicians need to be familiar with strategies to reduce the risk of these adverse events and to manage them when they arise.