When this happens, the drug will stop working. If you take a protease inhibitor by itself, resistance develops within one month. When you take more than one antiviral drug at the same time, HIV mutates much more slowly and it takes much longer for resistance to develop. Sometimes, if you develop resistance to one drug, you will also have resistance to other antiviral drugs. Researchers are excited about nelfinavir because it appears that it will not be cross-resistant with other protease inhibitors.
Resistance can develop quickly.
It is very important to take protease inhibitors according to instructions, on schedule, and not to skip or reduce doses. Nelfinavir is taken by mouth as a capsule. The capsules are 250mg, so you will take 3 capsules at a time. Late in 1999, the FDA approved twice-daily dosing of nelfinavir at 1250mg per dose. This means taking 5 capsules at a time.