Associations between Use of Antimalarial Medications and Health among U.S. Veterans of the Wars in Iraq and Afghanistan

Systematic Review of Psychiatric Adverse Effects Induced by Chloroquine and Hydroxychloroquine: Case Reports and Population Studies

OBJECTIVE

To perform a systematic review on the psychiatric adverse effects of chloroquine (CQ) and hydroxychloroquine (HCQ); to summarize what is known about psychiatric adverse effects of these drugs; to compare clinical trials, populational studies, and case report studies; and to increase awareness of the potential psychiatric adverse effects of these drugs.

DATA SOURCES

A literature search of PubMed, Scopus, and Web of Science was performed to identify manuscripts published between December 1962 and June 2022. Search terms included CQ, HCQ, psychiatry, psychosis, depression, anxiety, bipolar disorder, delirium, and psychotic disorders.

STUDY SELECTION AND DATA EXTRACTION

Relevant studies included reports of adverse effects after CQ or HCQ ingestion.

DATA SYNTHESIS

The current literature presents evidence for a risk of short-term psychiatric adverse effects induced by either CQ or HCQ. However, the populational-level studies presented some limitations regarding the voluntary response in survey data, self-report adverse effects, and placebo group reporting similar symptoms to the case group. Thus, populational-level studies addressing the discussed limitations and the nature and extent of possible psychiatric adverse effects are needed.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Most of the patients who developed such adverse effects did not report a family history of psychiatric disease. The frequency of psychiatric adverse effects depends on the patient's biological sex, age, and body mass index, but not on the drug dosage.

CONCLUSIONS

Based on clinical trials and case reports, the current literature presents evidence for a risk of short-term psychiatric adverse effects induced by either drug.

A Cross-sectional Cohort Study to Assess Long-term Neurocognitive and Psychiatric Symptoms of Mefloquine Use in Veterans

INTRODUCTION

To evaluate the associations between neurocognitive and psychiatric health outcomes with mefloquine or any antimalarial exposure.

MATERIALS AND METHODS

Medical records were systematically reviewed to identify veterans that indicated antimalarial medication use. Linear regression was performed to examine associations between mefloquine/antimalarial exposure and health outcomes. The mefloquine-exposed group was further compared with normative populations for the same health outcomes.

RESULTS

In the adjusted models, no significant differences were noted between the two exposure groups and the unexposed group for any of the health measures (P-value > 0.05). When compared to normative population samples, the mefloquine-exposed group had poorer health and greater neurobehavioral symptom severity or cognitive complaints.

CONCLUSION

This study suggests that mefloquine use by veterans referred for intensive evaluation of their military deployment exposures and health was not associated with increased, long-term, neurocognitive/psychiatric symptoms compared to unexposed veterans.

Review of the mechanism underlying mefloquine-induced neurotoxicity

Mefloquine, a potent blood schizontocide, is effective against drug-resistant Plasmodium falciparum. This property, along with its unique pharmacokinetic profile, makes mefloquine a widely prescribed antimalarial drug. However, several epidemiological studies have raised concerns on the safety of mefloquine as prophylaxis for malaria. Well-documented side-effects of mefloquine include abnormal dreams, insomnia, anxiety, and depressed mood, as well as nausea and dizziness (the last two most frequent effects). The mechanisms that underlie the neurological/psychiatric complications of mefloquine are poorly understood. The aim of this study was to review the literature on the neurotoxic mechanisms of action of mefloquine to better understand its potential toxicity in the central nervous system, highlighting the mechanisms that lead to its psychiatric disorders. Experimental studies on the neurotoxic effects of mefloquine discussed herein include brain transporters of mefloquine, alteration in neurotransmitters, disruption on calcium (Ca²⁺) homeostasis and neuroinflammation, generation of oxidative stress response in neurons (involving glutathione, increased F2-isoprostanes, accumulation of cytosolic lipid globules), and alteration of voltage-dependent channels, as well as gap junction intercellular communications. Although several hypotheses have been proposed for the mechanisms that mediate mefloquine-induced brain damage, they are not fully understood, necessitating additional studies in the future.