Tenofovir may require closer renal monitoring in older patients
The impact of age on tenofovir-related effects on estimated glomerular filtration rate (eGFR) were explored in a retrospective analysis of 1031 HIV-positive subjects receiving tenofovir as part of their antiretroviral regimen. Serum creatinine values were used to compute eGFR by the MDRD method.
The average eGFR at baseline was 112.7 mL/min and the median age was 43 years.
In a univariate analysis, there was a decrease in eGFR of 0.016 mL/min for each day of tenofovir use, an effect that persisted after controlling for age, baseline MDRD, race and gender. When age was added to a model controlling for days of tenofovir use, eGFR decreased by 0.638 mL/min for each year increase in age.
Individuals >50 years had an average eGFR 16 ml/min lower than individuals <50 years, which reduced to 4 ml/min lower than those <50 years after controlling for baseline eGFR. When subjects were further stratified by age (<30, 30-45, >45 years), individuals aged 30-45 had an average eGFR 9.54 mL/min less compared to those <30; individuals >45 had an average eGFR 11.9 mL/min less than those <30 years, after controlling for eGFR at baseline.
The authors of this study concluded that tenofovir may require closer monitoring in older individuals.
Ref: Goeddel L et al. Effect of Age on Renal Function with TDF. 11th PK Workshop, 2010. Abstract 38.