HIV Patient's Handbook/ Adherence to anti-HIV therapy regimen is critical if you want to make the therapy successful

What is a resistant virus?

If you reduce or stop medication by your self-judgment, the drug concentration in blood will decrease and suppression of viral replication will be incomplete which may incur the danger of developing viruses that do not react to drugs, known as drug-resistant viruses.

What is cross-resistance?

As a result of the emergence of drug-resistant viruses, other drugs which are structurally and/or functionally similar to the ones being used, will no longer work as cross-resistance develops.
If the therapy does not show any results, a drug-resistance test is carried out. The test result, along with viral loads, the number of CD4+ lymphocytes and the medication regimen are all taken into consideration and you should discuss with your doctor on whether the therapy should be altered.