ABSTRACT
Treatment homogeneity is valued in the medical profession. Uniform treatment guidelines are often used to ensure that all physicians prescribe a safe, efficacious, and cost-effective drug in treating a medical condition. However, such a policy may be undesirable when drug resistance is endogenous. In the case of infectious diseases, selection pressure imposed by the use of any single drug (antibiotic, antiviral, or antimalarial) sooner or later leads to the evolution of resistance (by bacteria, viruses, or parasites) to that drug. In this chapter, we show that a “mixed strategy” of multiple drug use is generally desirable and analytically characterize the conditions under which this strategy is optimal.
