Effects of khat use on response to antipsychotic medications in patients with newly diagnosed schizophrenia: a retrospective study

Antipsychotic medication non-adherence and factors associated among patients with schizophrenia in eastern Ethiopia

BACKGROUND

Given that antipsychotic medication is a cornerstone for treating and preventing relapse in people with schizophrenia, non-adherence has been indicated as a big challenge. This study aimed to assess antipsychotic medication non-adherence and factors associated among patients with schizophrenia in eastern Ethiopia.

METHODS

We conducted an institution-based cross-sectional study in two public hospitals in Eastern Ethiopia from December 1, 2022, to January 31, 2023. Antipsychotic medication adherence was assessed using MOrisky medication adherence rating scale questionnaire, and insight was measured using the self-report insight scale for Psychosis (ISP). Multiple stepwise logistic regression models with Adjusted Odds Ratio (AOR) and 95% confidence interval (CI) were applied to identify the factors. Statistical significance was considered at p-value ≤ 0.05.

RESULTS

We found that 44.57% of patients with schizophrenia experienced non-adherence to their antipsychotic medication. Being single (AOR = 2.48, 95% confidence interval [CI]:1.71, 3.58), alcohol users (AOR = 2.00, 95% confidence interval [CI]:1.46, 2.72), Khat chewers (AOR = 2.84, 95% confidence interval [CI]; 2.06, 3.90) and having no insight to their illness (AOR = 2.1, 95% confidence interval [CI]:1.52, 2.90) were more likely to be non-adherent to their antipsychotic medications.

CONCLUSIONS

Our study revealed that antipsychotic medication non-adherence was high among individuals suffering from schizophrenia and that it was influenced by various factors such as single marital status, alcohol usage, Khat chewing, and having no understanding of their condition. As a result, comprehensive intervention methods should be developed to address the factors associated with psychotropic medication non-adherence among patients. Healthcare professionals should pay attention to these aspects and consider developing specific strategies to promote adherence to medications while treating individuals with schizophrenia.

Is chewing khat associated with mental health disorders? A scoping review of the content and quality of the current evidence base

BACKGROUND

Khat (Catha edulis) is a plant commonly found in the horn of Africa whose leaves are chewed for their psycho-stimulant effects. Several studies have demonstrated the association between khat use and mental health problems. Nevertheless, evidence is mixed and inconsistent, warranting further review of available studies. This scoping review is aimed at investigating the content and quality of evidence base on the associations between khat use and mental health disorders and suggesting avenues for further research.

METHODS

We used a scoping review methodology to map the existing evidence using PubMed, SCOPUS, Embase, and CINAHL databases. Primary studies focusing on the association between any pattern of khat use and any form of mental health disorders are included. The review focused on all age groups, any study design, all geographical locations, and any publication year. The terms used for searching eligible studies include khat, mental disorders, and various alternative terminologies. Narrative review is employed to present findings.

RESULTS

7,121 articles were found, of which 108 were eligible, conducted across 12 different countries. The majority of the studies was done during the last ten years and the studies mostly employed cross-sectional design. About 10 different categories of mental health disorders have been identified as showing associations with khat use. Despite many contradictory findings between the studies, most of the evidence base suggests that khat use is associated with mental health disorders. Non-specific psychological distress is the most frequently mentioned mental health problem (reported in 26.9% of the studies). Khat use as a predictor variable is mostly assessed using a 'yes/no' category, and as a result, dose-dependent effects of khat use on mental health are not given much consideration.

CONCLUSION

Although most of the studies associate khat use with mental health disorders, the causal relationships are inconclusive given the cross-sectional design of the studies, and the presence of potential confounders and several forms of biases. Available studies also report contradictory findings. Further studies are recommended using prospective designs, standardized and valid measures of khat use, and focusing on specific types of mental health disorders.

Fatalities Involving Khat in Jazan, Saudi Arabia, 2018 to 2021

Interpreting fatalities involving khat is challenging due to a lack of data on cathinone and cathine reference concentrations in postmortem tissues. This study investigated the autopsy findings and toxicological results of fatalities involving khat in Saudi Arabia's Jazan region from 1 January 2018 to 31 December 2021. All confirmed cathine and cathinone results in postmortem blood, urine, brain, liver, kidney, and stomach samples were recorded and analyzed. Autopsy findings and the manner and cause of death of the deceased were assessed. Saudi Arabia's Forensic Medicine Center investigated 651 fatality cases over four years. Thirty postmortem samples were positive for khat's active constituents, cathinone and cathine. The percentage of fatalities involving khat was 3% in 2018 and 2019 and increased from 4% in 2020 to 9% in 2021, when compared with all fatal cases. They were all males ranging in age from 23 to 45. Firearm injuries (10 cases), hanging (7 cases), road traffic accident (2 cases), head injury (2 cases), stab wounds (2 cases), poisoning (2 cases), unknown (2 cases), ischemic heart disease (1 case), brain tumor (1 case), and choking (1 case) were responsible for the deaths. In total, 57% of the postmortem samples tested positive for khat only, while 43% tested positive for khat with other drugs. Amphetamine is the drug most frequently involved. The average cathinone and cathine concentrations were 85 and 486 ng/mL in the blood, 69 and 682 ng/mL in the brain, 64 and 635 ng/mL in the liver, and 43 and 758 ng/mL in the kidneys, respectively. The 10th-90th percentiles of blood concentrations of cathinone and cathine were 18-218 ng/mL and 222-843 ng/mL, respectively. These findings show that 90% of fatalities involving khat had cathinone concentrations greater than 18 ng/mL and cathine concentrations greater than 222 ng/mL. According to the cause of death, homicide was the most common fatality involving khat alone (77%). More research is required, especially toxicological and autopsy findings, to determine the involvement of khat in crimes and fatalities. This study may help forensic scientists and toxicologists investigate fatalities involving khat.

Protein-Ligand Identification and In Vitro Inhibitory Effects of Cathine on 11 Major Human Drug Metabolizing Cytochrome P450s

Cathine is the stable form of cathinone, the major active compound found in khat (Catha edulis Forsk) plant. Khat was found to inhibit major phase I drug metabolizing cytochrome P450 (CYP) enzyme activities in vitro and in vivo. With the upsurge of khat consumption and the potential use of cathine to combat obesity, efforts should be channelled into understanding potential cathine-drug interactions, which have been rather limited. The present study aimed to assess CYPs activity and inhibition by cathine in a high-throughput in vitro fluorescence-based enzyme assay and molecular docking analysis to identify how cathine interacts within various CYPs’ active sites. The half maximal inhibitory concentration (IC₅₀) values of cathine determined for CYP2A6 and CYP3A4 were 80 and 90 μM, while CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP2J2 and CYP3A5 showed no significant inhibition. Furthermore, in K_i analysis, the Lineweaver-Burk plots depicted non-competitive mixed inhibition of cathine on both CYP2A6 and CYP3A4 with K_i value of 63 and 100 μM, respectively. Cathine showed negligible time-dependent inhibition on CYPs. Further, molecular docking studies showed that cathine was bound to CYP2A6 via hydrophobic, hydrogen and π-stacking interactions and formed hydrophobic and hydrogen bonds with active site residues in CYP3A4. Both molecular docking prediction and in vitro outcome are in agreement, granting more detailed insights for predicting CYPs metabolism besides the possible cathine-drug interactions. Cathine-drug interactions may occur with concomitant consumption of khat or cathine-containing products with medications metabolized by CYP2A6 and CYP3A4.

Clinical characteristics and treatment outcomes of patients with newly diagnosed schizophrenia: A 4-year single-center experience in Saudi Arabia

Objectives

Understanding how local “psychiatry clinic” characteristics shape research findings is essential for applying research into evolution, outcomes, and costs of mental health. However, a paucity of “psychiatry clinics” details has implications for the interpretation and utilization of this research.

Methods

We reviewed data of 746 patients with new‐onset schizophrenia on antipsychotic monotherapy seen over four years in an “adult psychiatry clinic” at Jazan Health, Saudi Arabia. Protocol‐driven interviews and investigations were recorded prospectively and extracted from the medical records for the study. Summary statistics and logistic regression analyses were applied to assess patients' characteristics and outcomes.

Results

The median patient age was 32 (IQR 27‐39) years. Of patients, 589 (79.0%) were male, and 679 (91.0%) had a low‐level education. The median follow‐up duration was 51.4 (IQR 27.4‐96.3) weeks. The most used initial antipsychotic drugs were olanzapine (48.8%), haloperidol (13.9%), and aripiprazole (11.3%). The numbers of patients who retained the initial drug at 24 and 52 weeks were 539 (72.3%) and 325 (43.6%), respectively. The initial drug was changed in 246 (33.0%) patients. The median time to initial drug change was 43.9 (IQR 14.8‐85.0) weeks. The logistic regression demonstrated that male sex (P < 0.004), young adult age group (P < 0.027), predominant positive symptoms (P < 0.021), treatment with haloperidol (P < 0.024), and khat use (P < 0.006) were significant factors for drug change.

Conclusions

This clinical records study demonstrated substantial individual variations in characteristics and in responding to initial antipsychotic medication. Insight into these findings will facilitate the planning for comprehensive research programs.