CC8 – Drug potency

CC8. Drug potency refers to the amount of a drug, expressed as the concentration or dose, needed to produce a defined effect.

8.1. Potency depends on both target (affinity and efficacy) and tissue (receptor number and drug availability) parameters.

8.2. Agonist potency is most commonly measured as the effective concentration/dose required to produce 50% of the maximum response (EC₅₀ or ED₅₀).

8.3. Antagonist potency can be measured as the concentration that reduces the response to an agonist (pA2).

8.4. Drugs are often compared by their potency.