vastasmõjudele

Vastasmõjudele (antagonistic effects) describes situations in which one influence diminishes or counters another, yielding a net effect that is weaker than the sum of the parts or even opposite to one of them. The term is used across disciplines, including medicine, ecology, and psychology.

Pharmacology: When two drugs interact antagonistically, their combined effect is less than expected. Examples include competitive antagonism at receptor sites, where one drug blocks the action of another; and metabolic interactions where one compound speeds the breakdown of another, reducing its concentration.

Ecology: Antagonistic interactions occur when one species negatively affects another, such as predator-mediated suppression of prey populations, or interference competition that reduces coexistence.

Measurement and analysis: Researchers assess interactions by comparing observed outcomes to predictions under additive models. Common approaches include isobolograms, combination-index methods, or regression-based models to identify antagonism, additivity, or synergy.

Implications: Understanding antagonistic effects informs drug safety and efficacy, environmental management, and policy design, helping avoid unintended reductions in beneficial effects.

See also: drug interaction, synergism, isobologram, interaction effect.