Quetiapine-Induced Place Preference in Mice: Possible Dopaminergic Pathway

Prescription patterns of quetiapine for multiple drug abuse, depression, and psychosis: A retrospective study

Background

Quetiapine is an atypical antipsychotic prescribed for schizophrenia, bipolar disorder, multiple drug abuse (MDA), generalized anxiety disorder, severe depression, dementia, and mood disorders. Prescription of quetiapine varies according to use, with side effects increasingly reported with higher doses. Many previous case reports highlighted the misuse of the drug. Here we studied the prescribing patterns of quetiapine in multiple drug abuse (MDA), depression, and psychosis patients in the Madinah region in Saudi Arabia.

Methods

This is a retrospective single-center study carried out in the main referral hospital for mental health in Madinah, Saudi Arabia for the period December 2020 till December 2021.

Results

A total of 158 patients were included in this study. The mean age of the patients was 30.5 ± 10.1 years. Male presented for 89.9 % of the patients. In terms of quetiapine indications, 46.2 % of patients used it for MDA, 29.7 % for psychosis, and 24.1 for depression. For all patients, quetiapine was used with a mean daily dose of 285.2 ± 222 mg and for a mean duration of 13.9 ± 15.4 weeks. Quetiapine was prescribed with a mean of 2.1 ± 2.2 prescriptions. Comparison between different indications shows that quetiapine was more frequently prescribed for MDA (p < 0.001). The MDA patients were significantly younger than in other groups (p = 0.001). All patients who received quetiapine for MDA were males. However, MDA patients received a smaller dose of quetiapine than other indications (p < 0.001). There were no significant differences between groups in terms of the number of prescriptions, duration, and whether the patient was on other medications or not. These results have been confirmed by regression analysis, where male and younger ages represented a significant contributing factor to MDA compared to psychosis, 95 % CI: 8 x107 (8 x107 - 8 x107) and 0.943 (0.900---0.987), respectively.

Conclusion

Quetiapine was prescribed more frequently in MDA patients and younger individuals. Low dose was predominant in those patients, indicating a probability of drug abuse.

Dopamine Receptors: Is It Possible to Become a Therapeutic Target for Depression?

Dopamine and its receptors are currently recognized targets for the treatment of several neuropsychiatric disorders, including Parkinson’s disease, schizophrenia, some drug use addictions, as well as depression. Dopamine receptors are widely distributed in various regions of the brain, but their role and exact contribution to neuropsychiatric diseases has not yet been thoroughly studied. Based on the types of dopamine receptors and their distribution in different brain regions, this paper reviews the current research status of the molecular, cellular and circuit mechanisms of dopamine and its receptors involved in depression. Multiple lines of investigation of these mechanisms provide a new future direction for understanding the etiology and treatment of depression and potential new targets for antidepressant treatments.

Abuse and misuse of second-generation antipsychotics: an analysis using VigiBaseTM , the World Health Organisation pharmacovigilance database

The study aim was to assess the abuse/misuse potential of second-generation antipsychotics (SGAPs) using VigiBase^TM data. We extracted individual case safety reports (ICSRs) of 'Drug abuse, dependence, and withdrawal' involving SGAPs up to June 2018. We assessed disproportionate reporting by calculating the Information Component (IC), considering the lower end of the 95% credibility interval for IC (IC₀₂₅ ), and the Proportional Reporting Ratio (PRR). We identified 1,683 ICSRs recorded as 'abuse, dependence, and withdrawal' involving SGAPs, mainly quetiapine (n=1,089) and olanzapine (n=209). The disproportional reporting indicators highlighted an association between 'Drug abuse and dependence', and quetiapine, olanzapine, and ziprasidone, as indicated by the IC₀₂₅ (2.263, 0.259, and 1.051, respectively) and PRR values (3.929, 1.020, and 1.334, respectively). The abuse/misuse potential is confirmed for quetiapine and olanzapine and highlighted for the first time for ziprasidone. Physicians should consider these risks when prescribing these antipsychotics, especially to patients with history of drug abuse.

Neutrophil Myeloperoxidase-Mediated N-Demethylation of Quetiapine Leads to N-Desalkylquetiapine, a Pharmacologically Active Cytochrome P450 Metabolite

The atypical antipsychotic drugs, quetiapine and clozapine, are associated with idiosyncratic drug reactions (such as agranulocytosis or neutropenia) that are thought to involve reactive metabolites. Neutrophil myeloperoxidase (MPO) metabolism of quetiapine is not well-studied, but is metabolized by cytochrome P450. Based on structural similarity to clozapine, we hypothesized that quetiapine can be metabolized by MPO and that there is overlap between cytochrome P450 and MPO metabolism of quetiapine. The interaction of quetiapine and clozapine with MPO and MPO chlorination activity was studied using UV-vis spectrophotometry. The metabolites were characterized using liquid chromatography-mass spectrometry (LC-MS), and electron paramagnetic resonance (EPR) spectroscopy was used for detecting drug-catalyzed glutathione oxidation. In the presence of quetiapine, MPO compound II accumulated for about 7.5 min, whereas in the presence of clozapine, MPO compound II was not observed as it was rapidly reduced back to the resting state. Increasing quetiapine concentrations resulted in a decrease in MPO chlorination activity, while the opposite result was found in the case of clozapine. UV-vis spectral studies showed no change when quetiapine was oxidized in the absence and presence of chloride anion (Cl^-, to catalyze chlorination reactions). Significant changes, however, were observed in the same assay with clozapine, where Cl^- appeared to hinder the rate of clozapine metabolism. The MPO-catalyzed hydroxylated and dealkylated metabolites of quetiapine and hydroxylated metabolites of clozapine were observed from the LC-MS analyses, particularly when Cl^- was included in the reaction. In addition, hydroxylated, dealkylated, and a proposed sulfoxide metabolite of quetiapine were also observed in the reaction catalyzed by human microsomes/NADPH. Lastly, compared to quetiapine, clozapine metabolism by MPO/H₂O₂ and glutathione produced more glutathionyl radicals using EPR spin trapping. In conclusion, MPO/H₂O₂/Cl^- was shown to metabolize quetiapine to S-oxidation and P450-like dealkylation products, and quetiapine metabolites were generally less reactive than clozapine.