Treating tardive dyskinesia with ondansetron

Adjunctive ondansetron for schizophrenia: A systematic review and meta-analysis of randomized controlled trials

The serotonin 5-hydroxytryptamine type 3 (5-HT3) receptor has been implicated in the pathogenesis of schizophrenia. This meta-analysis of randomized controlled trials (RCTs) examined the efficacy and safety of adjunctive ondansetron, a potent 5-HT3 receptor antagonist, in the treatment of schizophrenia. Only RCTs examining adjunctive ondansetron for schizophrenia were included. Standardized mean difference (SMD), risk ratio (RR) and their 95% confidence intervals (CIs) were analyzed using RevMan, Version 5.3. Study quality was evaluated with the Cochrane risk of bias and the Jadad scale. Data of 5 RCTs (n = 304) covering 149 patients on ondansetron (4-8 mg/day) and 155 patients on placebo were analyzed. Three RCTs reported "randomized allocation" with a specific description; the weighted Jadad score was 3.8. Adjunctive ondansetron outperformed placebo in the reduction of Positive and Negative Syndrome Scale (PANSS) total score [3 RCTs, n = 171; SMD: -1.06 (95%CI: -2.10, -0.02), p = 0.04, I² = 85%], the negative [4 RCTs, n = 209; SMD: -0.96 (95%CI: -1.71, -0.22), p = 0.01, I² = 80%], and general psychopathology symptom scores [3 RCTs, n = 171; SMD: -0.97 (95%CI: -1.91, -0.02), p = 0.04, I² = 82%], but not in the positive (p = 0.05) and depressive symptom scores (p = 0.91). The difference in PANSS total score remained significant after excluding one outlying RCT [2 RCTs, n = 141; SMD: -0.50 (95%CI: -0.84, -0.16), P = 0.004, I² = 0%]. Four RCTs examined the effect of ondansetron on cognition applying different instruments yielding conflicting findings. Ondansetron was superior over placebo in improving extrapyramidal symptoms, but no group differences were found in overall discontinuation rate and adverse drug reactions. In conclusion, adjunctive ondansetron appears to be efficacious and safe in improving negative symptoms and general psychopathology. The effect of ondansetron on cognitive impairment in schizophrenia needs to be further explored in large-scale RCTs.

Add-on clinical effects of simvastatin and ondansetron in patients with schizophrenia stabilized on antipsychotic treatment: pilot study

OBJECTIVES

There is some evidence that anti-inflammatory treatment may have beneficial effects in schizophrenia and major depression. Statins are cholesterol-lowering agents but have been found to be anti-inflammatory and also decrease C-reactive protein (CRP). Ondansetron is a serotonin (5-HT3) receptor antagonist widely used to prevent nausea and vomiting in patients receiving chemotherapy for cancer. Small studies have suggested that adjunctive ondansetron is efficacious against schizophrenia symptoms. We carried out a feasibility study in schizophrenia patients (within 5 years of first diagnosis) to explore the adjunctive use of simvastatin and ondansetron on positive, negative and general psychopathology.

METHODS

This was a 12-week rater-blind placebo-controlled study. A total of 36 patients with DSM-IV diagnosis of schizophrenia were recruited, 12 in each arm. Patients were assessed at baseline and at 12 weeks using Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression (CGI) scale, Global Assessment of Functioning (GAF) and Abnormal Involuntary Movement Scale (AIMS).

RESULTS

Both simvastatin and ondansetron provide some evidence of a reduction in symptoms compared with treatment as usual (TAU) on PANSS total score, although this was not statistically significant. In the secondary analyses, no significant differences were seen on CGI, GAF and AIMS.

CONCLUSIONS

Anti-inflammatory treatments have been shown to have some beneficial effects in schizophrenia. Both simvastatin and ondansetron provide some evidence of a reduction in symptoms compared with TAU. This study has led to a larger Stanley Medical Research Institute (SMRI)-funded, double-blind, randomized control trial.

Are serotonin 3A and 3B receptor genes associated with suicidal behavior in schizophrenia subjects?

Suicide is a major contributor to the morbidity and mortality of schizophrenia, accounting for approximately 10% of deaths in these patients. Genetic factors have been reported to modulate the risk for suicide, although the precise mechanism and magnitude of the genetic contribution are unknown. Further, suicide attempters present abnormalities in the serotonergic system. We evaluated whether genetic variants in the serotonin receptors HTR3A (rs897692, rs1150226, rs1176724, rs2276302, rs3737457, rs897687 and rs1176713) and HTR3B (rs3758987, rs10502180, rs11606194, rs17116121, rs1176744, rs17116138, rs2276307, rs3782025 and rs1176761) were susceptibility components for suicidal behavior in 154 Caucasians schizophrenia subjects (20.1% of suicide attempters). In a second step, we compared haplotype and gene-gene interaction approaches because both genes are located in the chromosome 11q23 approximately 28Kbp apart. We did not observe allelic or genotypic associations. Six haplotypes were nominally significant associated with suicide. Gene-gene interaction using Helix Tree software showed two nominally significant interactions reproduced by haplotype association. Likewise, haplotypes composed by the markers included in the best multidimensional reduction three-locus model were nominally significant. Our results suggest that HTR3A and HTR3B polymorphisms may not play a major role in the susceptibility for suicidal behavior in schizophrenia subjects. Moreover, gene-gene interaction and haplotype association may have consistent results for genes located in the same chromosome.

The Role of Ondansetron in the Treatment of Schizophrenia

Objective:

To evaluate the efficacy of ondansetron for the treatment of schizophrenia.

Data Sources:

Searches of MEDLINE (1950–March 2010) and Google Scholar were performed. Key search terms included ondansetron, Zofran, serotonin antagonists, 5-HT, serotonin receptor, and schizophrenia.

Study Selection and Data Extraction:

All articles published in English identified from the data sources were evaluated. All studies and case reports evaluating ondansetron for the treatment of schizophrenia were reviewed.

Data Synthesis:

Six clinical trials, including 3 double-blind, randomized trials, and 2 case reports pertinent to ondansetron use in schizophrenia, were identified. Ondansetron daily doses ranged from 4 to 16 mg, with doses administered once or twice daily. Ondansetron was used as monotherapy in 3 trials and as an adjunct to therapy with clozapine, haloperidol, or risperidone, respectively, in 3 trials. Studies were of varying durations, ranging from a single-dose study with a 3-hour follow-up to three 12-week studies. Most studies evaluated ondansetron's efficacy in treating schizophrenia as measured with changes in Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale, and Clinical Global Impression scale scores. In the 2 largest trials, with a combined patient population of 151, treatment with adjunctive ondansetron resulted in statistically significant improvement in negative symptoms as assessed with PANSS. In all studies, ondansetron was well tolerated, with no severe adverse reactions reported.

Conclusions:

Ondansetron may be effective as an adjunct to antipsychotics for the treatment of schizophrenia, specifically negative symptoms, as assessed with PANSS. Due to the variation in concurrent therapies and dosing regimens, it is difficult to establish an optimal dose from the reviewed trials. Further large, randomized, double-blind, active-controlled studies would be helpful in determining the role of ondansetron in the treatment of schizophrenia.

Ondansetron: Tardive Dyskinesia

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. A summary of the most relevant data is provided, including background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .