Hidden suppressive interactions are common in higher-order drug combinations

Area of Science:

• Microbiology
• Pharmacology
• Evolutionary Biology

Background:

• Rising multi-drug resistant bacteria necessitates combination therapies.
• Drug combinations can exhibit suppressive effects, promoting bacterial growth.
• Standard analysis may overlook complex, higher-order drug interactions.

Purpose of the Study:

• To investigate the prevalence and impact of "hidden suppression" in multi-drug combinations.
• To analyze higher-order drug interactions beyond simple single-drug comparisons.
• To improve understanding of antibiotic resistance evolution under combination treatments.

Main Methods:

• Analysis of an extensive dataset including 5-drug combinations.
• Comparison of highest-order combinations against all lower-order combinations (single, 2-, 3-, and 4-drug).
• Identification of "hidden suppression" where higher-order combinations are worse than lower-order ones, but not single drugs.

Main Results:

• A significant majority (54%) of all drug combinations contained hidden suppression.
• Hidden suppression was observed across various orders of drug combinations.
• This phenomenon challenges typical interaction analysis methods.

Conclusions:

• Hidden interactions are critical for understanding the architecture of multi-drug effects.
• Failure to account for hidden suppression can lead to inaccurate predictions of antibiotic resistance evolution.
• Further research into complex drug interactions is vital for effective treatment strategies.