Drug substitution and rational therapeutics. Old problems and new challenges

Drug substitution is a reality of current medical practice. Physicians need to be aware of how it affects patients both medically and economically. Continuing education in clinical pharmacology is essential. Although generic substitution and formulary restriction are usually acceptable, therapeutic substitution is not. The responsibility of instituting therapy by writing a prescription must not be delegated to non-physicians. This could ultimately lead to more problems with adverse drug reactions and poor clinical outcome.