If two substances interact such that their combined effect is less than the sum of their individual effects, this interaction is described as

If two substances interact such that their combined effect is less than the sum of their individual effects, this interaction is described as

• A. Additive
• B. Antagonistic
• C. Synergistic
• D. Potentiating

Answer: (B)

Antagonism describes an interaction where the combined effect is smaller than the sum of the individual effects. One substance blocks or reduces the action of the other, or interferes with its metabolism or receptor binding, so the overall outcome falls short of what would be expected if you just added the two effects together. By contrast, additive means the effects simply add up, and synergistic means the combined effect is greater than the sum. Potentiating refers to boosting another substance’s effect, which isn’t what’s described here.

Antagonism describes an interaction where the combined effect is smaller than the sum of the individual effects. One substance blocks or reduces the action of the other, or interferes with its metabolism or receptor binding, so the overall outcome falls short of what would be expected if you just added the two effects together. By contrast, additive means the effects simply add up, and synergistic means the combined effect is greater than the sum. Potentiating refers to boosting another substance’s effect, which isn’t what’s described here.