Clinical Therapeutic Index

Some indices of relative safety or relative effectiveness cannot be defined explicitly and uniquely, although it is presumed that the same quantifiable and precise criteria of efficacy and safety will be used in comparing drugs of similar kinds. The Food and Drug Administration has considered the following definition of an improved Clinical Therapeutic Index to be used in comparing different drug combinations or formulations; the assumption is retained that an improved or "better" drug has a higher Clinical Therapeutic Index " (1) increased safety (or patient acceptance) at an accepted level of efficacy within the recommended dosage range, or (2) increased efficacy at equivalent levels of safety (or patient acceptance) within the recommended dosage range." Cf. Food and Drug Administration, Therapeutic Index, Standardized Safety Margin, Effective