Novel antiretroviral drugs and renal function monitoring of HIV patients

Chronic kidney disease is a major comorbidity in patients affected by HIV infection. In addition, the introduction of new antiretroviral agents that interact with creatinine transporters is raising some concerns. In this review we analyze the currently available data about three new antiretroviral drugs and one new pharmacokinetic enhancer. Three of them (rilpivirine, cobicistat, dolutegravir) have shown some interactions with renal function, while tenofovir alafenamide fumarate reduces the plasmatic concentration of the parent drug. The future use of tenofovir alafenamide seems to be encouraging in order to reduce the renal interaction of tenofovir. Rilpivirine, cobicistat, and dolutegravir reduce the tubular secretion of creatinine, inducing a decrease of estimated glomerular filtration rate according to creatinine. Rilpivirine and dolutegravir block the uptake of creatinine from the blood, inhibiting organic cation transporter 2, and cobicistat interacts with the efflux inhibiting multidrug and toxin extrusion protein 1. This effect can then be considered a "reset" of the estimated glomerular filtration rate according to creatinine. However, clinicians should carefully monitor renal function in order to identify possible alterations suggestive of a true renal functional impairment. Owing to the interference of these drugs with creatinine secretion, an alternative way of estimation of glomerular filtration rate would be desirable. However, at the moment, other methods of direct glomerular filtration rate measurement have a high impact on the patient, are not readily available, or are not reliable in HIV patients. Consequently, use of classic formulas to estimate glomerular filtration rate is still recommended. Also, tubular function needs to be carefully monitored with simple tests such as proteinuria, phosphatemia, urinary excretion of phosphate, normoglycemic glycosuria, and excretion of uric acid.