Acute facial neuralgia related to initiation of emtricitabine/tenofovir for HIV PrEP: a report of two cases in a PrEP demonstration trial

Background Emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) fixed-dose combination (FTC/TDF) is generally well-tolerated, although treatment-related adverse events have been reported.Methods We report two cases of persons using FTC/TDF PrEP who had acute neuralgia in a Chinese PrEP demonstration trial.Results Neurological symptoms subsided upon treatment discontinuation. Symptoms were reported as similar to one case's previous experiences with dolutegravir (DTG) + FTC + tenofovir alafenamide (TAF) (for PEP), leading to permanent discontinuation of PrEP.Conclusion Acute facial neuralgia appears to be a rare idiosyncratic adverse event to FTC/TDF. HIV PrEP is widely recommended as a crucial measure for HIV prevention. In a demonstration trial in China, this article highlights two cases where facial neuralgia emerged as an unexpected side effect of PrEP medication, not previously mentioned in official prescribing information. These findings deepen our understanding of the potential side effects of emitricitabine/tenofovir disoproxil fumarate use and provide empirical evidence to enhance PrEP implementation further and address the challenges that may arise during its utilisation.