Clozapine-reserpine combination for refractory psychosis

Chlorpromazine versus reserpine for schizophrenia

BACKGROUND

In the 1940s reserpine, refined from a plant extract that had been used for centuries, began to be used as a treatment for people with mental disorders and was one of the very first antipsychotic drugs. Its irreversible pharmacological potency and adverse effects meant that it has been withdrawn in the UK and its role has been superceded by 'newer' compounds. The effects of reserpine are of historical interest although there are some reports of it still being used in highly specialist situations in psychiatry. Chlorpromazine is also an old drug but it is still used for treatment of people with schizophrenia.

OBJECTIVES

To investigate the effects of two old medications (reserpine and chlorpromazine) for people with schizophrenia. Reserpine is now rarely used while chlorpromazine remains on the essential list of drugs of the World Health Organization (WHO).

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (24 March 2016).

SELECTION CRITERIA

We included randomised clinical trials focusing on chlorpromazine versus reserpine for schizophrenia that presented useable data.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. We employed a fixed-effect model for analyses. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.

MAIN RESULTS

The review currently includes nine studies with an average 60 participants per study. All of these studies are now over 60 years old, conducted between 1955 and 1962. When chlorpromazine was compared with reserpine for people with schizophrenia, improvement in global state was better at short term for those receiving chlorpromazine (n = 781, 6 RCTs, RR 'not improved' 0.75 95% CI 0.62 to 0.92, low-quality evidence). Short-term improvement in paranoid distortion was measured using the Multidimensional Scale for Rating Psychiatric Patients (MSRPP). Data showed no clear difference between treatment groups (n = 19, 1 RCT, RR 1.33 95% CI 0.62 to 2.89, very low-quality evidence). There was no difference in functioning: occupational adjustment, medium term (n = 40, 1 RCT, RR 0.83 95% CI 0.47 to 1.47, moderate-quality evidence) and general behaviour (n = 98, 1 RCT, RR 0.79 CI 0.41 to 1.53, moderate-quality evidence). Adverse events were poorly reported. For 'toxic reaction' there was, again, no obvious difference between the two compounds (n = 210, 3 RCTs, RR 1.68 95% CI 0.43 to 6.54, moderate-quality evidence), and this also applied to leaving the study early (n = 229, 4 RCTs, RR 1.16 95% CI 0.94 to 1.42, moderate-quality evidence).

AUTHORS' CONCLUSIONS

Judged by standards of today, the evidence is largely of limited quality. However, some of these 1950s studies are remarkable in their foresight and clarity. Reserpine did have some effect on global state - but chlorpromazine did seem to perform better. Important issues regarding adverse effects were not really addressed by these trials. Chlorpromazine remains on the WHO list of essential drugs. Reserpine is now almost obsolete, although, probably as a result of evidence other than that reported in the pioneering trials used in this review.

Tetrabenazine augmentation in treatment-resistant schizophrenia: a 12-week, double-blind, placebo-controlled trial

Evidence linking schizophrenia to alterations in presynaptic dopamine (DA) grows, although treatments to date have largely focused on postsynaptic D2 receptor blockade. This study examined augmenting response in treatment-resistant schizophrenia through the addition of tetrabenazine (TBZ), a presynaptic vesicular monoamine transporter (VMAT2) inhibitor. Participants included 41 outpatients (mean age, 43.5 years) with treatment-refractory schizophrenia, stabilized on their present antipsychotic treatment (clozapine, 73%) for more than 3 months. Individuals were randomly assigned to TBZ augmentation (12.5-75 mg/d), titrated according to a fixed, flexible schedule, or placebo over 12 weeks. Twenty subjects received TBZ, and 21 received placebo; doses of 18 of the 20 TBZ-treated individuals were titrated up to the maximum of 75 mg/d, and 16 (80%) of them completed the trial. Tetrabenazine was well tolerated and not linked to increased adverse effects, including those that have been reported more frequently (eg, parkinsonism, depression, and sedation) with higher doses (>100 mg/d) used in the treatment of hyperkinetic movement disorders. However, there was no indication of clinical improvement as measured using the Brief Psychiatric Rating Scale, the Clinical Global Impression scale, and the Global Assessment of Functioning scale. In examining those receiving TBZ-clozapine specifically, there was no indication of drug-drug interactions or difference in response compared to the overall sample. Tetrabenazine was not effective, as used here, in augmenting clinical response in treatment-resistant schizophrenia. It may be premature, however, to discount the potential benefits of VMAT2 inhibitors in treating psychosis in light of what is presently understood regarding presynaptic DA's role and evidence that "endogenous sensitization" may occur over the course of the illness.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with β-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder, and the use of propranolol for performance anxiety and akathisia.

Augmentation strategies in clozapine-resistant schizophrenia

The introduction of antipsychotics in the 1950s revolutionised the treatment of schizophrenia, but it soon became apparent that a substantial number of patients demonstrated a suboptimal response to these antipsychotics. Clozapine proved to be beneficial in patients whose symptoms were treatment resistant, but it too had limitations, with as many as 40-70% of those treated with clozapine demonstrating inadequate response to this drug as well. The availability of other 'atypical' antipsychotics offers options, but clozapine appears to remain the most effective option in treatment-resistant schizophrenia. This, of course, raises the question of what to do when clozapine is only partially effective. To address the issue of treatment in patients who have demonstrated a suboptimal response to clozapine, efforts have focused on a variety of augmentation strategies, including numerous medications and electroconvulsive therapy. The current body of evidence consists largely of data from smaller open trials and case series/reports, although data from a limited number of controlled studies are now available. Not surprisingly, the evidence drawn from the former is more supportive of augmentation strategies, although the controlled trials are not without positive findings. The available information is certainly not so overwhelming as to endorse any single augmentation approach. Indeed, it argues for more controlled data and cautions us regarding the cost-benefit ratio in adopting this strategy. Over and above the added adverse effects of another treatment, there is evidence to indicate that actual clinical worsening can occur. Without compelling evidence, clinicians must resort to guiding principles. The potential benefits of augmentation cannot be ruled out, but it should be approached with caution and in a systematic fashion. Factors compromising clozapine response should first be ruled out, and any augmentation trials should be guided by existing evidence and a treatment plan that incorporates a clear understanding of target symptoms. A means of evaluating outcome effectively needs to be in place, and the trial should be circumscribed to prevent needless polypharmacy. A priori, an endpoint needs to be established and the trial discontinued unless results firmly support added benefits.

Antipsychotic polypharmacy: is there evidence for its use?

Antipsychotic polypharmacy occurs frequently in clinical practice; however, there is a lack of controlled clinical studies testing the efficacy of the combinations used. The purpose of this literature review was to examine studies and other reports that have assessed the incremental benefits and deficits of combination antipsychotic therapy versus monotherapy. A PUBMED search covering a 26-year period from 1976 to 2002 was conducted. The search was limited to clinical trials, case series, and reports. Fifty-two reports were identified that systematically assessed the efficacy of combination therapy as opposed to monotherapy: 4 double-blind studies, 13 open-label clinical trials, and 35 case reports. Only one open-label trial and 2 case reports met the design criteria of having trials of each medication and the combination in the same patients and using some type of standardized assessment to evaluate outcome. The most frequent combination was clozapine-risperidone. Of the clinical trials, 75% (3/4) of the double-blind studies and 69% (9/13) of the open-label trials found that combination therapy was effective in reducing symptoms, while 37% (13/35) of case reports documented an overall positive outcome. Currently, the clinical practice of antipsychotic polypharmacy is not evidence-based; however, there is also no evidence against its use. Expanded systematic research to assess this clinical practice is needed.