Differential effect of haloperidol and clozapine on plasma homovanillic acid in elderly schizophrenic patients with or without tardive dyskinesia

Antipsychotic drugs for elderly patients with schizophrenia: A systematic review and meta-analysis

Elderly patients with schizophrenia are a particularly vulnerable group often excluded from clinical trials. Currently there is no evidence-synthesis about the efficacy and safety of antipsychotics in this subgroup. We reviewed all randomized-controlled-trials, about antipsychotics in elderly schizophrenics (last search Dec 12, 2017). Pairwise meta-analyses were conducted. The primary outcome was overall symptoms. Secondary outcomes included positive symptoms, negative symptoms, response, dropouts, quality of life, social functioning and side-effects. We included 29 references from 18 unique randomized-controlled-trials with 1225 participants published from 1958 to 2009. The definition of "elderly" was very heterogeneous across the studies (minimum age 46-65, mean age 57-73). There were evidence gaps for most drugs in many outcomes. In terms of efficacy paliperidone was associated with fewer dropouts due to inefficacy than placebo in the only placebo-controlled-trial. Olanzapine was superior to haloperidol in overall symptoms, negative symptoms and response, and it was associated with fewer dropouts than risperidone. Risperidone and haloperidol produced more prolactin increase than olanzapine, and olanzapine was associated with less use of antiparkinson medication than haloperidol. Although we found no marked differences of the effects of these drugs in the elderly, the evidence presented was based on very few usually small studies. To examine specifically whether there are differences in efficacy and side-effects in elderly, which differs in meaningful ways from the general population, studies in patients who are defined by critiera as truly geriatric, which incorporates older age together with multimorbidity and fraility dimensions, may be more informative.

Antipsychotic reduction and/or cessation and antipsychotics as specific treatments for tardive dyskinesia

BACKGROUND

Since the 1950s antipsychotic medication has been extensively used to treat people with chronic mental illnesses such as schizophrenia. These drugs, however, have also been associated with a wide range of adverse effects, including movement disorders such as tardive dyskinesia (TD) - a problem often seen as repetitive involuntary movements around the mouth and face. Various strategies have been examined to reduce a person's cumulative exposure to antipsychotics. These strategies include dose reduction, intermittent dosing strategies such as drug holidays, and antipsychotic cessation.

OBJECTIVES

To determine whether a reduction or cessation of antipsychotic drugs is associated with a reduction in TD for people with schizophrenia (or other chronic mental illnesses) who have existing TD. Our secondary objective was to determine whether the use of specific antipsychotics for similar groups of people could be a treatment for TD that was already established.

SEARCH METHODS

We updated previous searches of Cochrane Schizophrenia's study-based Register of Trials including the registers of clinical trials (16 July 2015 and 26 April 2017). We searched references of all identified studies for further trial citations. We also contacted authors of trials for additional information.

SELECTION CRITERIA

We included reports if they assessed people with schizophrenia or other chronic mental illnesses who had established antipsychotic-induced TD, and had been randomly allocated to (a) antipsychotic maintenance versus antipsychotic cessation (placebo or no intervention), (b) antipsychotic maintenance versus antipsychotic reduction (including intermittent strategies), (c) specific antipsychotics for the treatment of TD versus placebo or no intervention, and (d) specific antipsychotics versus other antipsychotics or versus any other drugs for the treatment of TD.

DATA COLLECTION AND ANALYSIS

We independently extracted data from these trials and estimated risk ratios (RR) or mean differences (MD), with 95% confidence intervals (CI). We assumed that people who dropped out had no improvement.

MAIN RESULTS

We included 13 RCTs with 711 participants; eight of these studies were newly included in this 2017 update. One trial is ongoing.There was low-quality evidence of a clear difference on no clinically important improvement in TD favouring switch to risperidone compared with antipsychotic cessation (with placebo) (1 RCT, 42 people, RR 0.45 CI 0.23 to 0.89, low-quality evidence). Because evidence was of very low quality for antipsychotic dose reduction versus antipsychotic maintenance (2 RCTs, 17 people, RR 0.42 95% CI 0.17 to 1.04, very low-quality evidence), and for switch to a new antipsychotic versus switch to another new antipsychotic (5 comparisons, 5 RCTs, 140 people, no meta-analysis, effects for all comparisons equivocal), we are uncertain about these effects. There was low-quality evidence of a significant difference on extrapyramidal symptoms: use of antiparkinsonism medication favouring switch to quetiapine compared with switch to haloperidol (1 RCT, 45 people, RR 0.45 CI 0.21 to 0.96, low-quality evidence). There was no evidence of a difference for switch to risperidone or haloperidol compared with antipsychotic cessation (with placebo) (RR 1 RCT, 48 people, RR 2.08 95% CI 0.74 to 5.86, low-quality evidence) and switch to risperidone compared with switch to haloperidol (RR 1 RCT, 37 people, RR 0.68 95% CI 0.34 to 1.35, very low-quality evidence).Trials also reported on secondary outcomes such as other TD symptom outcomes, other adverse events outcomes, mental state, and leaving the study early, but the quality of the evidence for all these outcomes was very low due mainly to small sample sizes, very wide 95% CIs, and risk of bias. No trials reported on social confidence, social inclusion, social networks, or personalised quality of life, outcomes that we designated as being important to patients.

AUTHORS' CONCLUSIONS

Limited data from small studies using antipsychotic reduction or specific antipsychotic drugs as treatments for TD did not provide any convincing evidence of the value of these approaches. There is a need for larger trials of a longer duration to fully investigate this area.

Inter- and intra-individual variability in the levels of plasma homovanillic acid in schizophrenic patients

BACKGROUND

Changes in the levels of homovanillic acid in blood plasma (pHVA) may reflect changes which occur in the brain. In healthy individuals, this concentration of pHVA is stable over time.

METHODS

Over the course of one month, we studied 98 acute schizophrenic patients who had not been taking any medication but were administered neuroleptics upon hospital admission, together with 23 chronic schizophrenic patients on long-term treatment from whom medication was withdrawn. Blood samples were taken at regular intervals from each individual and the concentration of plasma homovanillic acid was measured.

RESULTS

We found relative stable values of pHVA with an intraclass correlation coefficient of 0.363 in acute patients and 0.638 (p<0.0001) in chronic patients, although no differences were found in mean values (13.79 and 14.18 microg/L, respectively) or in the variation range (7.20 to 26.7 microg/L and 6.96 to 29.96 microg/L respectively). The index of individuality was calculated to be 1.36 in acute patients and 0.74 in chronic patients.

CONCLUSIONS

Despite the wide range of values in the concentration of pHVA and the presence of pharmacological stimuli, we found a certain reproducibility in the levels of this dopamine metabolite. These findings are consistent with the idea that the dopaminergic activity is characterized by a constitutive value which would be under genetic control. The higher stability observed in chronic patients may reflect a weaker, age-related dopaminergic plasticity; conversely, it may indicate that a lack of plasticity in response to a pharmacological stimulus may be an indicator of poorer prognosis.

Antipsychotic medication for elderly people with schizophrenia

BACKGROUND

A large and growing number of older people across the world suffer from schizophrenia. Recommendations for their treatment are largely based on data extrapolated from studies of the use of antipsychotic medications in younger populations. In addition most manufacturers of such medications recommend prescription of reduced doses to the elderly. The evidence base for these assumptions is unclear and raises obvious questions regarding the appropriateness of such prescribing practice.

OBJECTIVES

To find and assimilate good evidence of the effects of antipsychotic medication for treatment of schizophrenia in people over 65 years of age.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (May 2003). We inspected references of all included studies for further trials and contacted relevant pharmaceutical companies.

SELECTION CRITERIA

All clinical randomised trials evaluating antipsychotic drugs for schizophrenia and schizophrenia-like psychoses in older people.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For homogenous dichotomous data, the random effects, relative risk (RR), and 95% confidence interval (CI) and, where appropriate, the numbers needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD).

MAIN RESULTS

Two hundred and fifty two elderly people with schizophrenia participated in three relevant randomised controlled studies. We were unable to extract usable data on quality of life, satisfaction, service use, or economic outcomes. One small study (n=18) compared thioridazine with remoxipride (RR leaving the study early 1.0 CI 0.07 to 13.6). A second study (n=175) compared risperidone with olanzapine. Global state 'not improved/worse' was not significantly different between treatments (n= 171, RR 1.26 CI 0.8 to 1.9); mental state PANSS total endpoint scores were also equivocal (n=171, RR 0.98 CI 0.76 to 1.26) as were all cognitive function tests. The third study (subset n=59) compared olanzapine with haloperidol and mental state change scores (BPRS WMD -3.60 CI -10.8 to 3.6; PANSS WMD -6.00 CI -18.3 to 6.3) were equivocal.

AUTHORS' CONCLUSIONS

Antipsychotics may be widely used in the treatment of elderly people with schizophrenia, however, based on this systematic review, there are little robust data available to guide the clinician with respect to the most appropriate drug to prescribe. Clearly reported large short, medium and long-term randomised controlled trials with participants, interventions and primary outcomes that are familiar to those wishing to help elderly people with schizophrenia are long overdue.

Electron spin resonance spectroscopy reveals alpha-phenyl-N-tert-butylnitrone spin-traps free radicals in rat striatum and prevents haloperidol-induced vacuous chewing movements in the rat model of human tardive dyskinesia

The typical antipsychotic drug haloperidol causes vacuous chewing movements (VCM) in rats, which are representative of early-Parkinsonian symptoms or later-onset extrapyramidal side effects of tardive dyskinesia (TD) in humans. Haloperidol (HP) has been hypothesized to potentiate increases in oxidative stress or free radical-mediated levels of toxic metabolites in rat striatum while simultaneous upregulating dopamine (DA)-D2 receptors leading to presumed DA supersensitivity. Alpha(alpha)-Phenyl-N-tert-butylnitrone (PBN) is an antioxidant used to combat oxidative stress and measure increases in PBN spin-adduct activity. Thus, the aim of this study was to investigate whether VCMs are related to upregulation of DA-D2 receptors or to increased levels of free radicals produced during oxidative stress, and whether PBN had any protective effects. Rats received daily chronic (28 day) i.p. injections of saline, haloperidol (2 mg/kg), PBN (150 mg/kg), or haloperidol + PBN. The VCM model was used to measure extrapyramidal side effects of drug treatments. Electron spin resonance (ESR) spectroscopy was performed to compare concentrations of free radical species in rats receiving injections of HP + PBN. To examine the upregulation of DA-D2 receptors, binding assays were carried out to assess the increase in DA-D(2) receptor numbers with respect to VCMs following treatment of rats injected with HP, PBN, and HP + PBN. Results of these experiments show that HP-induced VCMs in rats results from increases in oxidative cellular events and may not be related to increases in striatal DA-D(2) receptors.

Clozapine versus typical neuroleptic medication for schizophrenia

BACKGROUND

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: 25-33% of patients have illnesses that are treatment-resistant. Clozapine is an atypical antipsychotic drug, which is claimed to have superior efficacy and to cause fewer motor adverse effects than typical drugs for people with treatment-resistant illnesses. Clozapine carries a significant risk of serious blood disorders, which necessitates mandatory weekly blood monitoring at least during the first months of treatment.

OBJECTIVES

To evaluate the effects of clozapine for schizophrenia in comparison to typical antipsychotic drugs.

SEARCH STRATEGY

Publications in all languages were searched from the following databases: Biological Abstracts (1982-1999), The Cochrane Library CENTRAL (Issue 2, 1999), Cochrane Schizophrenia Group's Specialised Register (1999), EMbase (1980-1999), ISI Citation Index, LILACS (1982-1999), MEDLINE (1966-1999), and PsycLIT (1974-1999). Reference list screening of included papers was performed. Authors of recent trials and the manufacturer of clozapine contacted.

SELECTION CRITERIA

All randomised controlled trials comparing clozapine with typical antipsychotic drugs were included by independent assessment by at least two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by at least two reviewers. Authors of trials published since 1980 were contacted for additional and missing data. Odds ratios (OR) and 95% confidence intervals (CI) of homogeneous dichotomous data were calculated with the Peto method. A random effects model was used for heterogeneous dichotomous data. Where possible the numbers needed to treat (NNT) or needed to harm (NNH) were also calculated. Weighted or standardised means were calculated for continuous data.

MAIN RESULTS

Currently the review includes 31 studies, 26 of which are less than 13 weeks in duration. These studies include 2589 participants, most of whom were men (74%). The average age was 38 years. There was no difference in the effects of clozapine and typical neuroleptic drugs for broad outcomes such as mortality, ability to work or suitability for discharge at end of the study. Clinical improvement was seen more frequently in those taking clozapine (random effects OR 0.4 CI 0.2-0.6, NNT 6) both in the short and the long term. Also, in the short term, participants on clozapine had fewer relapses than those on typical antipsychotic drugs (OR 0.6 CI 0.4-0.8, NNT 20 CI 17-38), and this may be true for long-term treatment as well. Symptom assessment scales showed a greater reduction of symptoms in clozapine-treated patients. Clozapine treatment was more acceptable than low-potency antipsychotics such as chlorpromazine (OR 0.6 CI 0.4-0.9) but did not differ from acceptability of high-potency neuroleptics such as haloperidol (random effects OR 0.8 CI 0.4-1.5). Clozapine was more acceptable in long-term treatment than conventional antipsychotic drugs (random effects OR 0.4 CI 0.2-0.7, NNT 6 CI 3-111). Patients were more satisfied with clozapine treatment (OR 0.5 CI 0.3-0.8, NNT 12 CI 7-37), but they experienced more hypersalivation, temperature increase, and drowsiness than those given conventional neuroleptics. However, clozapine patients experience fewer motor side effects and less dry mouth. The clinical efficacy of clozapine was more pronounced in participants resistant to typical neuroleptics in terms of clinical improvement (random effects OR 0.2 CI 0.1-0.5, NNT 5 CI 4-7) and symptom reduction. Thirty-two percent of treatment resistant people had a clinical improvement with clozapine treatment.

REVIEWER'S CONCLUSIONS

This systematic review confirms that clozapine is convincingly more effective than typical antipsychotic drugs in reducing symptoms of schizophrenia, producing clinically meaningful improvements and postponing relapse. Patients were more satisfied with clozapine treatment than with typical neuroleptic treatment. (ABSTRACT TRUNCATED