Determining the Interaction in a Drug Combination using the Dose-based or Effect-based Method

Abstract: The interaction in a drug combination can be assessed using either the method of Chou or Jin’s method. The combination index in the former (i.e., CI-C) is calculated based on doses, while the latter (i.e., CI-J) is based on effects. This perspective demonstrates a correlation between 1/CI-C and CI-J when applied to both released and simulated data. Thus, 1/CI-C and CI-J are functionally equivalent for evaluating drug interaction. Combining these two indices is preferred; consistency shows a reliable verdict, and inconsistency indicates a requirement for further analyses. However, it has been observed that evaluating released data raises certain concerns.