Abacavir usage patterns and hypersensitivity reactions in the EuroSIDA cohort. HIV Medicine
Roen et al. on behalf of the EuroSIDA study aimed to describe the proportion of individuals initiating abacavir (ABC) and to describe the incidence and factors associated with hypersensitivity reactions (HSR) among those prescribed ABC.
Between 2009 and 2016, of 10’076 individuals receiving combination antiretroviral therapy (cART), 3’472 (34%) had ever received ABC-based cART. Poisson models showed lower ABC utilization in older individuals, and in those with higher CD4 cell counts, higher cART lines, and prior AIDS. Higher ABC utilization was associated with higher HIV RNA and poor renal function, and was more common in Central-East and Eastern Europe and lowest during 2014.
During 779 person-years of follow-up (PYFU) in 2’139 individuals starting ABC after 1 January 2009, 113 discontinued ABC within 6 weeks of initiation for any reason [incidence rate (IR) 14.5 (95% confidence interval (CI) 12.1, 17.5) per 100 PYFU], 13 because of reported HSR [IR 0.3 (95% CI 0.1, 1.0) per 100 PYFU], and 35 because of reported HSR/ any toxicity [IR 4.5 (95% CI 3.2, 6.3) per 100 PYFU]. There were no factors significantly associated with ABC discontinuation because of reported HSR/any toxicity.
In conclusion, ABC remains a commonly used drug throughout Europe, and the incidence of reported HSR among those on ABC is low, probably attributable to screening for HLA-B*5701, improved patient care and a greater understanding and awareness of HSR. Because EuroSIDA does not collect genetic screening information, it is unknown which individuals were tested for HLA-B*5701, or whether the frequency of testing varied between regions and/or over calendar time.