[Prevention and treatment of antipsychotic induced weight gain]. / Preventie en behandeling van gewichts-toename bij antipsychotica.

BACKGROUND: Metformin is the most investigated pharmacological treatment of antipsychotics-induced weight gain (AIWG). Based on a systematic literature review, the first guideline for the treatment of AIWG with metformin was recently published. AIM: To present a step-by-step plan, based on recent literature and clinical experience to monitor, prevent, and treat AIWG. METHOD: Literature search to give specific advice on the choice of antipsychotic medication, stop, dose reduction or switch of antipsychotic, screening, non-pharmacological and pharmacological interventions to prevent and treat AIWG. RESULTS: Especially in the first year of antipsychotic treatment timely detection of AIWG through regular monitoring is pivotal. The best way to treat AIWG is to prevent its emergence by choosing an antipsychotic with a favourable metabolic profile. Secondly, by titration of antipsychotic medication to the lowest dose possible. Achieving a healthy lifestyle shows a limited beneficial effect on AIWG. Drug-induced weight loss can be attained by the addition of metformin, topiramate, or aripiprazole. Topiramate and aripiprazole can improve positive and negative residual symptoms of schizophrenia. The evidence on liraglutide is scarce. All augmentation strategies may cause side effects. Besides, in case of nonresponse augmentation therapy should be stopped to prevent unnecessary polypharmacy. CONCLUSION: In the revision of the Dutch multidisciplinary guideline for schizophrenia, the detection, prevention, and treatment of AIWG deserves more attention.

Genome-wide association analyses of symptom severity among clozapine-treated patients with schizophrenia spectrum disorders.

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia. However, response is highly variable and possible genetic underpinnings of this variability remain unknown. Here, we performed polygenic risk score (PRS) analyses to estimate the amount of variance in symptom severity among clozapine-treated patients explained by PRSs (R2) and examined the association between symptom severity and genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activity. Genome-wide association (GWA) analyses were performed to explore loci associated with symptom severity. A multicenter cohort of 804 patients (after quality control N = 684) with schizophrenia spectrum disorder treated with clozapine were cross-sectionally assessed using the Positive and Negative Syndrome Scale and/or the Clinical Global Impression-Severity (CGI-S) scale. GWA and PRS regression analyses were conducted. Genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activities were calculated. Schizophrenia-PRS was most significantly and positively associated with low symptom severity (p = 1.03 × 10-3; R2 = 1.85). Cross-disorder-PRS was also positively associated with lower CGI-S score (p = 0.01; R2 = 0.81). Compared to the lowest tertile, patients in the highest schizophrenia-PRS tertile had 1.94 times (p = 6.84×10-4) increased probability of low symptom severity. Higher genotype-predicted CYP2C19 enzyme activity was independently associated with lower symptom severity (p = 8.44×10-3). While no locus surpassed the genome-wide significance threshold, rs1923778 within NFIB showed a suggestive association (p = 3.78×10-7) with symptom severity. We show that high schizophrenia-PRS and genotype-predicted CYP2C19 enzyme activity are independently associated with lower symptom severity among individuals treated with clozapine. Our findings open avenues for future pharmacogenomic projects investigating the potential of PRS and genotype-predicted CYP-activity in schizophrenia.

[COVID-19 and severe mental illness, especially in clozapine use]. / COVID-19 en ernstige psychiatrische aandoeningen, in het bijzonder bij clozapinegebruik.

BACKGROUND: The Clozapine Plus Working Group is frequently consulted for advice on measures in case of infection with SARSCoV-2 and on vaccination against COVID-19 in patients receiving clozapine.

AIM: Inform about risks of infection with SARS-CoV-2 in patients with severe mental illness (SMI), patients with schizophrenia spectrum disorders (SSD), and patients treated with clozapine. Advise on monitoring of clozapine plasma levels and white blood cell count and differential in COVID-19 and after vaccination, as well as measures to be taken.

METHOD: Literature research and case studies.

RESULTS: SMI patients and in particular SSD patients have an increased risk of infection with SARS-CoV-2 with more hospitalizations and higher mortality than non-psychiatric patients. Patients using clozapine may be at greater risk of infection. SARS-CoV-2 infection may cause a dangerous increase of clozapine plasma levels and generally mild and short-term granulocytopenia and lymphocytopenia, which are usually not a result of clozapine treatment.

CONCLUSION: In case of COVID-19 extra alertness is required in patients with SMI and especially SSD. In clozapine users, in case of COVID-19, reduction in dose by half to three quarters of the original dose is recommended. When patients develop granulocytopenia, SARS-CoV-2 should be considered as the cause and not immediately clozapine. SMI patients and clozapine users in particular belong to a high risk group with a medical indication for early vaccination.

Adjunctive memantine in clozapine-treated refractory schizophrenia: an open-label 1-year extension study.

BACKGROUND: In a recent placebo-controlled, double-blind crossover trial (n = 52), significant beneficial effects on memory (d = 0.30) and negative symptoms (d = 0.29) were found after 12 weeks of memantine augmentation in patients with clozapine-refractory schizophrenia. In this open-label 1-year extension study we report the long-term effects and tolerability of memantine add-on therapy to clozapine. METHOD: Completers of the first trial who experienced beneficial effects during 12 weeks of memantine treatment received memantine for 1 year. Primary endpoints were memory and executive function using the Cambridge Neuropsychological Test Automated Battery, the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression Severity Scale (CGI-S). RESULTS: Of 31 randomized controlled trial completers who experienced beneficial effects from memantine, 24 received memantine for 1 year. The small improvement in memory found in the memantine condition in the placebo-controlled trial remained stable in the extension study. Executive function did not improve. After 26 weeks of memantine add-on therapy to clozapine, PANSS negative symptoms (r = 0.53), PANSS positive symptoms (r = 0.50) and PANSS total symptoms (r = 0.54) significantly improved. Even further significant improvement in all these measures was observed between 26 weeks and 52 weeks of memantine, with effect sizes varying from 0.39 to 0.51. CGI-S showed a non-significant moderate improvement at 26 weeks (r = 0.36) and 52 weeks (r = 0.34). Memantine was well tolerated without serious adverse effects. CONCLUSIONS: In the 1-year extension phase the favourable effect of adjunctive memantine on memory was sustained and we observed further improvement of negative, positive and overall symptoms in patients with clozapine-treated refractory schizophrenia.

Memantine augmentation in clozapine-refractory schizophrenia: a randomized, double-blind, placebo-controlled crossover study.

BACKGROUND: Dysfunction of neuroplasticity due to N-methyl-d-aspartate (NMDA) receptor hypofunction may be a causal factor for memory and executive dysfunctioning in schizophrenia. Deregulation of NMDA transmission in the prefrontal cortex may also explain negative and positive symptoms. Clozapine augmentation with memantine targets altered NMDA receptor-mediated neurotransmission in schizophrenia and showed substantial beneficial effects on several symptom domains in a small proof-of-concept study. We evaluate effects of memantine add-on treatment to clozapine for memory and executive function, and negative and positive symptoms in schizophrenia. METHOD: Clozapine-treated patients with refractory schizophrenia were randomly assigned to 12 weeks of double-blind adjunctive treatment with memantine (n = 26) or placebo (n = 26). Crossover occurred after a 2-week placebo wash-out period. Primary endpoints were change from baseline to 12 weeks treatment and 14 weeks to 26 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Side effects were assessed using the Liverpool University Neuroleptic Side-Effect Rating Scale. RESULTS: When compared with placebo, memantine improved a composite memory score comprising verbal recognition memory and paired associates learning task scores on the CANTAB (effect size = 0.30) and PANSS negative subscale score (effect size = 0.29). Side effects were mild and transient. CONCLUSIONS: In patients with clozapine-treated refractory schizophrenia, memantine addition significantly improved verbal and visual memory and negative symptoms without serious adverse effects. These results justify further investigations on long-term memantine augmentation to clozapine in treatment-resistant schizophrenia.

Non-glutamatergic clozapine augmentation strategies: a review and meta-analysis.

Persistent negative symptoms and cognitive impairment are major clinical problems in the treatment of schizophrenia. There is no convincing evidence regarding the efficacy of augmentation of clozapine with a second antipsychotic, ethyl eicosapentaenoic acid (E-EPA), an antidepressant, a mood stabilizer or extract of Ginkgo biloba in clozapine-resistant schizophrenia. We present an overview of studies in which the potential clinical utility of the addition of non-glutamatergic agents to clozapine is assessed. We performed a meta-analysis on the efficacy of both risperidone and aripiprazole compared to placebo. We compared the effects of the addition of a second antipsychotic or an antidepressant to clozapine on positive, negative, overall and affective symptoms of schizophrenia in double-blind placebo-controlled trials.

Clozapine augmented with glutamate modulators in refractory schizophrenia: a review and metaanalysis.

Clozapine is an efficacious antipsychotic drug for patients with treatment-resistant schizophrenia, but does not sufficiently improve these symptoms in a substantial proportion of this population. There is no convincing evidence for the efficacy of any clozapine augmentation strategy. New evidence suggests that glutamate receptors are a candidate target for therapeutic effects in schizophrenia. We present an overview of studies assessing the potential clinical utility of adding glutamatergic agents to clozapine. We conducted 3 metaanalyses of data on positive, negative and overall symptoms of schizophrenia, analysing results from 3 studies on clozapine augmentation with glycine, 6 studies on lamotrigine add-on therapy to clozapine and 4 studies on topiramate addition to clozapine.

The glutamate hypothesis: a pathogenic pathway from which pharmacological interventions have emerged.

We discuss the relevance of the glutamate hypothesis in explaining cognitive disturbances and negative symptoms in schizophrenia. 4 lines of evidence support the hypothesis that glutamate deregulation, mainly through dysfunction of the N-methyl-D-aspartate (NMDA) receptor, is an important underlying mechanism of schizophrenia. Glutamate pathways are promising sites for intervention. Glutamate agonists combined with non-clozapine antipsychotics and glutamate antagonists augmented to clozapine show interesting clinical benefits in refractory schizophrenia. We illustrate how unique properties of the NMDA receptor antagonist memantine in addition to clozapine, may cause improvement of positive, negative and cognitive symptoms of schizophrenia.

[Life threatening symptoms of withdrawal of gamma-hydroxybutyrate]. / Levensbedreigende onthoudingsverschijnselen door gammahydroxyboterzuur.

Acute psychosis and extreme agitation brought about by gamma-hydroxybutyrate GHB withdrawal can be life-threatening. In order to prevent states of excitement accompanied by aggression and somatic complications it is advisable to intervene by administering strong sedatives. It is argued that GHB should be tapered off as an alternative treatment for fixation and high doses of benzodiazepines.

[A female patient with late-onset schizophrenia and fear of Katwijk disease]. / Een patiënte met laat ontstane schizofrenie en angst voor de Katwijkse ziekte.

A 66-year-old patient had suffered from late-onset schizophrenia from the age of 44. Her family history included reports of brain haemorrhages, possibly resulting from hereditary amyloidal angiopathy of the Dutch type (Katwijk disease). She was very afraid for having this disease. The progression of the psychiatric symptoms and the age at which they began, led us to suspect an organic process. Differential diagnoses that were discussed included cerebral amyloidal angiopathy, frontal lobe dementia and Huntington's disease.