Monitoring kidney function

While taking antiretroviral therapy, regular kidney function monitoring is the best way to prevent kidney problems. At minimum, monitoring should include urinalysis and measurement of serum creatinine and phosphate. Many experts prefer more additional measures, such as creatinine clearance and glomerular filtration rate.

Kidney function screening should be performed before starting antiretroviral therapy; the Infectious Diseases Society of America (IDSA) recommends that this be done at the time of HIV diagnosis.¹ Ongoing monitoring should then be performed regularly during treatment with potentially toxic drugs.

The IDSA recommends periodic kidney function monitoring during the first six months, then twice annually for patients taking indinavir. The European Medicines Agency (EMEA) guidelines advise that patients receiving tenofovir should be monitored every four weeks for the first year and thereafter, every three months. Patients who have pre-existing kidney impairment, are taking other potentially nephrotoxic drugs, or are otherwise at increased risk should receive more frequent monitoring, as often as every few weeks.

It is important that kidney function monitoring continue throughout the course of treatment. Whilst drug-related kidney toxicity typically emerges during the first six to twelve months, later emergence of kidney stones and tenofovir-induced nephrotoxicity has been reported.² More frequent kidney function monitoring is recommended for children.