The new antipsychotics--some pharmacological aspects of their problems and potential

Current therapy issues and unmet clinical needs in the treatment of schizophrenia: a review of the new generation antipsychotics

This review discusses the atypical antipsychotics, focusing on the possibility of symptom reduction with a minimum of side-effects. A selective review of clinically relevant reports, studies and meta-analyses is presented. The results from clinical trials suggest that atypical agents improve negative and affective symptoms, and cognitive functioning more than typical antipsychotics, but that the pattern of effects on these domains, as well as on suicidality, appears to differ. In clinical trials, the newer drugs generally have less extrapyramidal side-effects (EPS) than typical antipsychotics. However, amisulpride, risperidone, olanzapine and ziprasidone still show evidence of a dose-related increase in EPS, whereas clozapine, quetiapine, sertindole and aripiprazole do not. Weight gain, increased blood lipids/cholesterol, and insulin resistance/type 2 diabetes are emerging as significant treatment-associated concerns, particularly for clozapine and olanzapine. Sedation has been reported for all the newer compounds except sertindole. The considerable variation in benefit/risk profiles of the atypical compounds can help the clinician to select the most appropriate treatment for individual patients.

Switching from conventional to novel antipsychotic drugs: results of a prospective naturalistic study

OBJECTIVE

We examined the long-term consequences of switching patients from conventional to novel antipsychotic drugs, from a patient's perspective.

METHODS

In a prospective, single-blinded, naturalistic study, a cohort of subjects (n=150) with schizophrenia or schizo-affective disorder (DSM-IV) were switched from conventional neuroleptic drugs to either risperidone (n=50), olanzepine (n=50) or quetiapine (n=50), and monitored for a period of 2 to 6 years. The ensuing natural history of transitions in treatments was charted, and the outcomes including symptoms, side effects, subjective tolerability of drugs and their impact on quality of life were documented with standardized rating scales.

RESULTS

Majority (85%) of the subjects benefited from a switch to the novel antipsychotic drugs, though some preferred to return to their original neuroleptic (8%), and others eventually required clozapine (7%) therapy. Novel antipsychotic drugs were significantly tolerated better, and had a positive impact on treatment-adherence, psychosocial functioning and quality of life. Among the novel drugs, risperidone was significantly better in improving negative symptoms, while olanzepine was particularly well tolerated and effective against comorbid anxiety and depressive symptoms. Patients treated with quetiapine reported fewer side effects, and showed a significantly greater improvement in neurocognitive deficits.

CONCLUSION

Novel antipsychotics emerged as the drug of choice in view of their overall effectiveness, though conventional neuroleptics and clozapine will continue to have a limited but distinct role in the management of schizophrenia. The challenge for clinicians lies in matching a patient's clinical and biochemical profile with that of a drug's pharmacological actions, in order to achieve optimum outcomes.

Antipsychotic drug use in neurodegenerative disease in the elderly: problems and potential from a pharmacological perspective

The past decade has seen the introduction of several new antipsychotics for the treatment of schizophrenia. These drugs demonstrate substantially lower levels of extrapyramidal side effects (EPS) than the classical antipsychotics, as well as having (often poorly supported) claims of increased efficacy at ameliorating certain schizophrenic syndromes. Increasingly, these 'atypical' drugs are being used in the treatment of psychotic or related behavioural disturbances in patients with neurodegenerative disease. Thus, some newer antipsychotics are particularly valuable in ameliorating the L-dopa-induced psychosis in Parkinson's disease, while behavioural problems in dementing disorders, such as those occurring in Alzheimer's disease, are also frequently treated by antipsychotic drugs. The relationship between drug pharmacology and neurotransmitter pathology is essential to understanding the relative efficacy of individual antipsychotic drugs in treating the psychotic and behavioural disturbances of neurodegenerative disorders.