CLINICAL HANDBOOK OF SCHIZOPHRENIA

17. Side Effects of Antipsychotics 171Abnormal Involuntary Movements Scale (AIMS; Simpson, Lee, Zoubok, & Gardos,1979). An AIMS examination should be repeated at least every 6 months during the useof antipsychotics. Should a patient develop problematic TD while being prescribed anantipsychotic, the clinician should consider stopping antipsychotic treatment if possible,switching the patient to an atypical antipsychotic (a different atypical antipsychotic, ifone is currently prescribed), or switching to clozapine. A number of studies have shownsymptomatic benefit when switching patients who developed TD during treatment with aconventional antipsychotic or an atypical antipsychotic to a different atypical antipsychotic(especially clozapine). For example, in an open-label study involving seven patientswith schizophrenia and severe TD, the effects of clozapine treatment (mean dose, 428mg/day) were evaluated over 5 years. Symptom scores decreased 83% from baseline after3 years and 88% from baseline after 5 years. The effects of risperidone (mean dose, 3.6mg/day) on preexisting severe TD were examined over 48 weeks in 40 patients withschizophrenia. At the end of the trial, mean AIMS scores had decreased significantly frombaseline (from 15.7 to 10.6). Significant improvement was noted after 8 weeks ofrisperidone treatment and maintained throughout the study period. Individually, totalAIMS scores decreased from baseline in 35 of the 40 patients treated, and increased in 5of the patients (Bai et al., 2005).A variety of adjunctive treatments for TD, including lithium, physostigmine, melatonin,and benzodiazepines, have been tried but without consistent benefit. Beneficial useof antioxidants such as vitamin E to prevent TD also has not been convincingly proven.Neuroleptic Malignant SyndromeNeuroleptic malignant syndrome (NMS) is a serious and potentially life-threatening idiosyncraticreaction to antipsychotics. Although the risk of developing NMS appears to begreater with the use of high-dose, high-potency conventional antipsychotics, reports ofNMS linked to atypical antipsychotics exist. The most common symptoms of NMS, oftenwith an onset of hours to days, are (lead pipe) rigidity, fever, autonomic instability, anddelirium. Renal failure, cardiac arrhythmias, seizures, and coma may also occur. Treatmentof NMS includes prompt removal of the offending antipsychotic and aggressivesupportive care. Use of the muscle relaxant dantrolene (1–3 mg/kg per day in divideddoses) to decrease rigidity and secondary hyperthermia, with or without bromocriptine(2.5–10 mg, three times daily) to potentially speed recovery has been advocated. Prudentselection of antipsychotics is necessary when restarting therapy in patients with schizophrenia.Atypical antipsychotics with a low likelihood of EPS and NMS, such asquetiapine and clozapine, should be considered.HYPOTHALAMIC- AND PITUITARY-RELATED SIDE EFFECTSHyperprolactinemia, resulting from dopaminergic receptor (D 2 ) blockade on lactotrophcells, occurs frequently in patients prescribed high-potency conventional antipsychoticsand high-dose risperidone but is uncommon with other atypical antipsychotics. For example,in a study involving approximately 400 inpatients prescribed a conventionalantipsychotic or risperidone for at least 3 months, prolactin levels above the upper rangeof normal occurred in 60% of women and 40% of men. Prolactin levels usually returnedto normal within 2–4 days of antipsychotic discontinuation. Symptoms of hyperprolactinemiacan be problematic and include gynecomastia, galactorrhea, sexual dysfunction,and amenorrhea. Methodologically sound studies of women treated with conventional