Potential drug-drug interactions in the psychiatric hospital: Frequency analysis

A scoping review of literature on clozapine from former USSR states published in Russian language

OBJECTIVE

Access to literature on clozapine in Russian language remains strikingly limited. We aimed to identify and translate clinical evidence on clozapine-based treatment outcomes.

METHODS

We performed a systematic review in PubMed, Embase and scientific indexes from former USSR states searching for articles published in Russian from the database inception till January 2023 and summarized the data in a scoping review (PROSPERO Reg. Number CRD42023386737).

RESULTS

A total of 60 papers were included comprising eight main topic categories: 1) clozapine-related intoxications (n = 20), 2) effectiveness/efficacy and safety of clozapine treatment (n = 14), 3) adverse drug-induced reactions (ADRs) related to clozapine treatment (n = 9), 4) therapeutic drug monitoring for clozapine (n = 5), 5) combination of clozapine and non-pharmacological treatments (n = 4), 6) pharmacoepidemiology of clozapine (n = 3), 7) effects of clozapine on the brain electrical activity (n = 3), and 8) novel clozapine formulations (n = 2). Among clozapine-related intoxications there were reports of criminal poisoning, which was associated with low lethality. Worse outcomes were accompanied by systemic reactions to intoxications. Clinical benefits of hemoadsorption were reported in the management of clozapine-related intoxications. Only half of studies reporting clozapine effectiveness used standardized scales to assess outcomes. Clozapine superiority in treatment-resistant schizophrenia (TRS) was replicated in one trial. No reports of clozapine-related agranulocytosis were identified. Clozapine ranked among most prescribed antipsychotics for TRS and non-TRS.

CONCLUSIONS

As clinical research in former USSR states is advancing to adopt western clinical research standards, comparability and extrapolation of findings is expected to increase, with transfer of older findings to clinical practice being particularly challenging.

Potential Drug-Drug Interactions among Patients with Schizophrenia Spectrum Disorders: Prevalence, Association with Risk Factors, and Replicate Analysis in 2021

Background and Objectives: Patients with schizophrenia are often exposed to polypharmacotherapy, which may lead to drug-drug interactions. The aim of the study was to investigate the prevalence of potential drug-drug interactions (pDDIs) in hospitalized patients with schizophrenia spectrum disorders and to identify factors associated with pDDIs and manifested symptoms and signs. Materials and Methods: This cross-sectional observational study included 311 inpatients admitted to a psychiatric hospital. The LexiComp drug interaction program was used to identify pDDIs in 2014. Factors associated with the prevalence of pDDIs and factors related to clinically observed symptoms and signs were assessed using multivariable regression. In addition, replicate analysis of pDDI was performed using 2021 program updates. Results: The prevalence of pDDIs was 88.7%. Our study showed that more than half of the patients received at least one drug combination that should be avoided. The most common pDDIs involved combinations of two antipsychotics or combinations of antipsychotics and benzodiazepines, which can lead to cardio-respiratory depression, sedation, arrhythmias, anticholinergic effects, and neuroleptic malignant syndrome. The number of prescribed drugs was a risk factor for pDDIs (OR 2.85; 95% CI 1.84-5.73). All groups of clinically observed symptoms and signs were associated with the number of drugs. In addition, symptoms and signs characteristic of the nervous system and psychiatric disorders were associated with antipsychotic dosage (IRR 1.33; 95% CI 1.12-1.58), which could contribute to the development of extrapyramidal syndrome, insomnia, anxiety, agitation, and bipolar mania. The 2021 version of the drug interaction program showed a shift in drug interactions toward a lower risk rating, implying less severe patient management and possibly less alert fatigue. Conclusions: Patients with schizophrenia spectrum disorders are at high risk of developing drug-drug interactions. Optimization of drug therapy, patient monitoring, and use of drug interaction programs could help to prevent pDDIs and subsequent adverse drug events.

Medication-related problems in geriatric psychiatry-a retrospective cohort study

OBJECTIVES

Information on medication-related problems (MRPs) in elderly psychiatric patients is scarce. In the present study, we analyzed the frequency and characteristics of MRPs in patients ≥60 years treated on the gerontopsychiatric ward of Hannover Medical School in 2019.

METHODS

Taking advantage of an interdisciplinary approach, two independent investigators screened hospital discharge letters of 230 psychiatric inpatients for clinically relevant MRPs, followed by validation through an interdisciplinary expert panel. Drug interactions as a subset of MRPs were analyzed with the aid of two different drug interaction programs.

RESULTS

230 patients (63.0% female, mean age 73.7 ± 8.4 years, median length of stay 18 days) were prescribed a median of 6 drugs. In total, 2180 MRPs were detected in the study population and 94.3% of the patients exhibited at least one MRP. Patients displayed a median of 7 MRPs (interquartile range 3-15). Pharmacodynamic interactions accounted for almost half of all MRPs (48.1%; 1048/2180). The number of drugs prescribed and the number of MRPs per patient showed a strong linear relationship (adjusted R²  = 0.747).

CONCLUSION

An exceedingly high proportion of elderly psychiatric inpatients displayed clinically relevant MRPs in the present study, which may be explained by the multimorbidity prevalent in the study population and the associated polypharmacy. The number of drug interactions was largely in accordance with previous studies. As a novel finding, we detected that a considerable proportion of elderly psychiatric inpatients were affected by potential prescribing omissions, potentially inappropriate duplicate prescriptions, and insufficient documentation.