Affinity

Definition

Affinity is the strength of the interaction between a drug and its receptor. Higher affinity means the drug binds more tightly to its target receptor, often leading to greater potency.

5 Must Know Facts For Your Next Test

1. Drugs with high affinity for their receptors can produce effects at lower concentrations.
2. Affinity is crucial in determining a drug's potency and efficacy.
3. In competitive binding scenarios, drugs with higher affinity can displace those with lower affinity from their receptors.
4. Understanding a drug's affinity helps predict therapeutic and side effects.
5. Affinity does not equate to activation; some high-affinity drugs may be antagonists.

Review Questions

• What does high affinity indicate about a drug's interaction with its receptor?
• How does affinity influence the dosage required for a drug to be effective?
• Why is it important to consider affinity when evaluating potential side effects of a drug?

Related terms

Potency: The amount of a drug needed to produce a given effect.

Efficacy: The maximum response achievable from an applied or dosed agent.

Agonist: A substance that fully activates the receptor that it binds to, producing a biological response.