resistance time lines

Question

Dr Daar, I know this is a wide opened question with no real fact based answers but is there a time line to when a resistance builds up to hiv even when your adherence is excellent?

Answer

Thank you for excellent question. Unfortunately there is no one answer. In general those initiating therapy that results in viral load declining to below the limits of detection will not experience viral rebound or develop drug resistance if they continue to reliably take their medications. Obviously there are no absolutes, but in general this is true.

In those that do not suppress viral load to undetectable levels then even with perfect adherence resistance will develop. For some drugs such as the NNRTIs such as efavirenz (Sustiva), 3TC (Epivir) and FTC (emtricitabine) it develops in weeks while for other drugs such as protease inhibitors used with pharmacologic boosting by ritonavir (norvir) resistance tends to develop more slowly.

I hope this helps. Best, Eric