Creatine kinase elevation in HIV-1-infected patients receiving raltegravir-containing antiretroviral therapy: a cohort study

Results: There were 475 patients who had been exposed to raltegravir for a median of 11.5 (IQR 8.2‐15.2) months. An increase of creatine kinase ≥3-fold ULN was detected in 53 (11.2%) patients, representing an incidence of 3.8/100 person-years. Symptoms were reported by seven patients (1.5%), they showed either grade 1( n¼3) or 2 (n¼4) creatine kinase increases. The median duration of raltegravir therapy before creatine kinase elevation was 5.9 (IQR 3.3‐9.3) months. Evidence of creatine kinase elevation prior to raltegravir therapy [hazard ratio (HR) 3.30; 95% CI 1.59+6.86; P ¼0.001], abnormal baseline creatine kinase (HR 3.24; 95% CI 1.63+6.45; P ¼0.001) and male gender (HR 4.17; 95% CI 1.33+1.27; P ¼0.001) were identified as independent risk factors for creatine kinase elevation during raltegravir treatment. Conclusions: Although �1 in 10 patients on raltegravir therapy developed significant creatine kinase elevation as defined in this study, symptoms were uncommon, not severe and occurred in patients with easily identifiable risk factors.