Adjusting the dosage for darunavir (Prezista), dolutegravir (Tivicay), or lamivudine (Epivir) in older PLWH is currently not necessary, a small study published in AIDS showed.
As people age, their livers and kidneys clear drugs and other substances more slowly, potentially causing greater drug concentrations to remain in the body. To assess the extent to which this may be relevant to antiretroviral usage among older people living with HIV, study participants older than 55 were drawn from the Swiss HIV Cohort. While single-point pharmacokinetic data was available for 804 people, a full investigation could only be performed in 19 participants, 17 of whom were men.
Medication clearance and exposure were compared between those older than 65 years of age and those younger than 65. Study authors noted that these parameters can vary significantly independent of age. Thus, the observed 40% lower boosted darunavir clearance and the 11% higher lamivudine exposure in the older group compared to the younger one were not clinically significant.
Pharmacokinetic values were similar to previously reported variations, study authors noted. The 18-hour t½ clearance time for dolutegravir in the older group (compared to 12 hours in 56- to 65-year-olds) also should make little difference, since that drug is usually taken once a day, they wrote.
“Advanced age does not affect boosted darunavir, dolutegravir, and lamivudine pharmacokinetics to a clinically significant extent,” study authors concluded. That said, they called for additional studies on antiretrovirals in older PLWH.