The use of lipid emulsion therapy in severe hydroxychloroquine overdose - a narrative review of case reports

Introduction: Hydroxychloroquine has cardiac and cerebral sodium channel- and human ether-à-go-go-related gene (HERG) potassium channel-blocking effects. This causes depolarization delays, resulting in cardiovascular toxicity with potentially fatal consequences. Despite several supportive care options, hydroxychloroquine poisoning remains difficult to treat. Its high lipid solubility suggests that lipid emulsion therapy might be beneficial; however, no clear evidence regarding its efficacy is available. The aim of this review is to assess the evidence, the outcomes, and adverse events regarding the use of intravascular lipid emulsion therapy as a treatment for hydroxychloroquine poisoning.

Methods: We conducted a systematic search in PubMed, Embase.com, Cochrane Central Register of Controlled Trials (CENTRAL)/Wiley, Web of Science Core Collection/Clarivate Analytics, and Scopus/Scopus.com from inception until 1 November 2023. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria encompassed original observational or interventional studies, case series and case reports describing patients receiving lipid emulsion therapy for hydroxychloroquine toxicity. We extracted clinical data and performed a quality assessment of the included cases. We present the results as a narrative synthesis.

Results: Of 157 identified articles, 16 case reports met the inclusion criteria, reporting on 18 patients. Lipid emulsion therapy was always associated with additional treatments, and detailed information on the circumstances regarding the administration of intravenous lipid emulsion and its presumed effect was often lacking. Fifteen of 18 patients survived to hospital discharge. Some reports described clear and almost immediate clinical improvement after intravenous lipid emulsion administration. No clear adverse effects were reported.

Discussion: A limitation is the reliance on case reports, which varied in the degree of reported details. The administration of multiple therapeutic drugs in most cases made it difficult to attribute survival primarily to lipid emulsion. Publication bias may favour cases with successful outcomes.

Conclusion: Among published case reports, most patients who received lipid emulsion for treatment of hydroxychloroquine poisoning survived. The risk of bias, the small number of reports, and the lack of systematic reporting of both favourable and adverse effects limit any conclusions about the effectiveness of lipid emulsion for hydroxychloroquine poisoning.