Treatment of schizophrenia

Risperidone (Risperdal): clinical experience with a new antipsychosis drug

Risperidone (Risperdal) is a benzisoxazole derivative with a high affinity for serotonin 5-HT2 and dopamine D2 receptors, and some affinity for alpha- adrenergic, histamine H1 and dopamine D1 receptors. It has no anticholinergic effects. Early studies demonstrated risperidone to be an effective medication for psychotic symptoms, probably more so than the older neuroleptics for both positive and negative symptoms. At clinically effective doses, risperidone causes no more extrapyramidal side-effects (EPS) than placebo; at higher doses EPS frequency increases in a dose-dependent manner. Since it became available in 1994, extensive experience with the drug supports favourable early impressions of efficacy and tolerability. Minimal sedation, relatively little weight gain and absence of anticholinergic manifestations contribute to the relative tolerability of risperidone as compared to older neuroleptics. However, risperidone is associated with hyperprolactinaemia which can result in amenorrhoea and sexual dysfunction. Compared to older neuroleptics, pharmacoeconomic studies have shown that use of risperidone is associated with reduced hospitalisation and direct cost savings. A recent study found equivalent efficacy between risperidone and clozapine for treatment-resistant patients. Two studies comparing risperidone and olanzapine have yielded positive but conflicting findings. The overall positive experience with risperidone has resulted in the drug being widely recommended as a first line treatment option for psychoses.

Use of antipsychosis and adjunctive medications by an inner urban community psychiatric service

OBJECTIVE

The aim of this paper is to survey patterns of use of new generation and conventional antipsychosis and adjunctive drugs by an inner urban community psychiatric service.

METHOD

All prescriptions for antipsychosis medications and all patients receiving these drugs in May 1998 were identified. Case record review yielded demographic and diagnostic data. Information was also obtained directly from prescribers.

RESULTS

Of 859 patients, 77% received antipsychosis medication; 53% of prescriptions for antipsychotics were for new generation drugs: risperidone (42%), olanzapine (37%) and clozapine (21%). Mean doses were 4.1+/-2.5 mg (risperidone), 14.7+/-8.2 mg (olanzapine) and 377.4+/-178.9 mg (clozapine). Doses for men tended to be higher than those for women, but the differences were not significant. DSM-IV diagnosis was schizophrenia for 74% of patients on atypicals, but patients with other diagnoses were also being treated with these drugs. Risperidone was more commonly used in combination with benzodiazepines and anticholinergics than olanzapine and clozapine, while clozapine was less likely to be combined with antidepressants and mood stabilisers. Of the conventionals, 66% were in depot form, mostly because of non-compliance. Combinations of antipsychotics were prescribed to 13% of patients.

CONCLUSION

New generation antipsychosis medications were prescribed more commonly than conventional drugs in this service for a wide range of diagnoses. Adjunctive medications were commonly utilised. These findings underline the clinical complexity of antipsychotic treatment in a changing environment.

Dose-response relationships for the antipsychotic effects and Parkinsonian side-effects of typical neuroleptic drugs: practical and theoretical implications

1. From a review of published literature it is concluded that the minimum dose of a neuroleptic drug (NLD) required to alleviate psychosis is very similar to that producing minimal parkinsonian side effects (PSE). This conclusion is reached both from group comparisons and individual comparisons of dose/response relations (DRR) for the two effects. 2. A lower dose of NLD is usually sufficient to prevent relapse in well stabilized patients than is needed to check an active psychotic state. 3. Anticholinergic agents used to reduce side effects of typical NLD can retard the therapeutic process during neuroleptic treatment of acute psychosis. Although it is not fully established that this is a central interaction, it is consistent with the idea that minimal side effects are a necessary condition for therapeutic effectiveness with typical antipsychotic drugs. 4. In relapse-free maintenance of psychosis-prone patients, tolerance occurs to PSE. Thus few patients need experience prolonged side effects during maintenance treatment with neuroleptics. 5. The evidence reviewed is discussed with respect to a previous hypothesis of the supposedly "indirect" action of typical neuroleptic drugs in therapy for psychosis. The evidence is consistent with the idea of a close causal relation between minimal PSE of these drugs, and their therapeutic effectiveness in the acute stage of treatment.

The role of the general practitioner in the treatment of schizophrenia: specific issues

This article provides practical guidelines for general practitioners in treating schizophrenia. Specific areas include pharmacological treatment, supportive therapy, depression and suicide, alcohol and drug abuse, sexuality, and physical health.

Minimizing the non-extrapyramidal side-effects of antipsychotics

Standard neuroleptic medications have been augmented by the introduction of risperidone and clozapine into clinical practice. A great deal of attention has also been focused on efficacy and the lower propensity to extrapyramidal side-effects associated with the new agents. However, antipsychotic medication, both old and new, can cause a range of other adverse effects, some of which are serious, and many of which have the potential greatly to diminish the quality of life of patients who need to take medication in the long term. Of particular significance are postural hypotension, cardiotoxicity, peripheral and central anticholinergic effects, sedation, weight gain, and endocrine and haematological effects. Various antipsychotic compounds differ substantially with regard to propensity to adverse effects. Side-effects can be minimized by optimization of clinical strategies, including choice of appropriate drug, slow titration and dosage reduction. It is also vital to explain carefully to both patients and carers the nature of the side-effects which can be anticipated. The choice of antipsychotic is often determined by evaluation of the potential impact of the various adverse effects on a particular patient. New drugs, such as risperidone, are well tolerated, with fewer side-effects, and should now be considered as a first-line option.

The Australian multicentre double-blind comparative study of remoxipride and thioridazine in schizophrenia

A double-blind, randomized study of parallel group design comparing remoxipride and thioridazine (dose range 150-600 mg/day of either drug) was undertaken at 11 Australian centres. A total of 144 patients (remoxipride = 73, thioridazine = 71) with DSM-III-R schizophrenia or schizophreniform disorder commenced the study, and 89 patients (remoxipride = 45, thioridazine = 44) completed the 6 weeks of the trial. The mean daily doses at last rating were 404 mg (remoxipride) and 378 mg (thioridazine). Initial Brief Psychiatric Rating Scale scores decreased by a mean 8.7 points in both remoxipride and thioridazine groups. Equivalent treatment responses were also confirmed by Clinical Global Impression. During the study, sedatives or hypnotics were needed by 68% of the remoxipride patients and 51% of the thioridazine patients. Thioridazine was associated with more postural hypotension, drowsiness, increased sleep, headache, dizziness on rising, dry mouth, sexual dysfunction and weight gain, while remoxipride patients reported more insomnia. There were no differences between remoxipride and thioridazine on dystonia, hypokinesia, dyskinesia, rigidity and akathisia. The results indicate that remoxipride has similar antipsychotic efficacy to thioridazine but causes fewer side effects.

Symptomatic response to antipsychotics differs between recent onset and recurrent chronic schizophrenic patients

The symptomatic response to standard antipsychotic treatment was assessed over the first 4 weeks of hospitalisation in 39 patients with DSM-III schizophrenia, active phase, using the Brief Psychiatric Rating Scale (BPRS). While highly significant improvement was noted overall, 36% of patients either did not improve or worsened. Furthermore there was no diminution in the withdrawal-retardation factor of the BPRS. Patients experiencing their first admission to hospital, all with recent-onset illness, were then compared with patients who presented with a recurrence and had illness of at least 3 years duration. Despite similarities in overall response, withdrawal-retardation scores did not diminish in recent-onset patients, in contrast to multiple admissions who demonstrated significant improvement. These findings suggest greater responsiveness of negative symptoms to treatment in patients with longstanding illness, and possibly a poorer prognosis in first admission patients with deficit manifestations.