R263K Mutation Leading to Failure of Dolutegravir-Based Treatment in a HIV Patient also Receiving Rifampicin: A Case Report

Background: Cases of treatment failure in patients developing the R263K mutation have been previously reported. Here we present a patient who developed resistance to dolutegravir due to the R263K mutation during rifampicin treatment. Case presentation: A patient with human immunodeficiency virus (HIV) had a virological failure of HIV when he used dolutegravir (DTG, once a day) and rifampicin at the same time. After treatment failure the dose of dolutegravir was increased (50mg, twice daily), but expected response was not achieved. The R263K mutation was identified and rifampicin was stopped. The treatment regimen was changed to zidovudine combined with lamivudine and lopinavir/ritonavir. Along with the regimen changes, the HIV-RNA, CD4, and CD8 of the patient improved. Due to the DTG drug-drug interactions with rifampicin, the dose of DTG should be doubled when used with rifampicin. Otherwise the patient might be at risk of developing treatment failure and the INSTI drug resistance R263K mutation. Conclusion: This case report discusses a possibility of developing resistance to dolutegravir due to the R263K mutation during rifampicin treatment, stressing the importance of detailed medical history and adherence, as well as the problem of drug-drug interactions in the follow-up process.