On testing for drug/chemical interactions: definitions and inference
Related Experiment Video
Updated: Oct 10, 2026

Diagonal Method to Measure Synergy Among Any Number of Drugs
Published on: June 21, 2018
1Department of Biostatistics, Virginia Commonwealth University, Medical College of Virginia, Richmond 23298-0032, USA.
Abstract:
The notion of zero interaction in the statistical literature is not always equivalent to what is found in the toxicology literature. A discussion about when they are the same is provided here. Design issues are of paramount importance in the analysis of drug combinations (mixtures of chemicals) when the number of constituents in the combination is larger than, say, three as the usual factorial designs are not feasible. An economical design necessary and sufficient to support the estimation of an additivity model is single drug (chemical) dose-response data. Once estimated, the additivity surface can be used to make comparisons to the observed data at combination points of interest. Examples are provided to demonstrate the methods.
Related Concept Videos
Drug toxicity: Drug–Drug Interaction
Agonism and Antagonism: Quantification
To quantify these effects, researchers use a dose-response curve, which provides valuable information about the potency and efficacy of a drug. Potency refers to...
Drug-Receptor Interactions
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue.
Pharmacokinetics: Drug–Drug Interactions
Drug Discovery: Overview
Drug-Receptor Interaction: Antagonist
Antagonists can be classified as competitive or noncompetitive based on their...

