Below, Dr. Susan Ball, Associate Professor at the Weill Cornell College of Medicine, talks about the importance of drug compliance in HIV treatment, and some of the issues HIV patients struggle with on a daily basis.
How do drug manufacturers determine the timing and dosing of HIV medications?
Drug companies arrive at drug dosing by trying to inhibit the virus for the longest amount of time in the body, with the lowest drug levels in the blood. Some of these drugs, depending on how they are metabolized, don't last very long in the bloodstream or in the place where they are going to be the most effective. As a result, the drug needs to be given more frequently. They work to reduce the concentration of the drug needed so that they can minimize side effects.
Often when a drug first comes to market, it will be in a form that is difficult to take: either multiple pills per day, or by injection only, or it will have side effects that make it unpleasant, if not intolerable. AZT, for instance, was one of the earlier HIV drugs, and had to be taken every four hours. Norvir, a protease inhibitor, used to be offered in doses that made most patients too nauseated to tolerate it. Manufacturers try to make the drugs more and more palatable in terms of reducing the number of pills, the side effect profile, and the number of times a day that you have to take a medication.
