Table 1.

Definitions of generic and therapeutic substitution

• Generic substitution occurs when a different formulation of the same drug is substituted. All generic versions of a drug are considered by the licensing authority to be equivalent to each other and to the originator drug.

• Therapeutic substitution is the replacement of the originally-prescribed drug with an alternative molecule with assumed equivalent therapeutic effect. The alternative drug may be within the same class or from another class with assumed therapeutic equivalence.