What does the term 'efficacy' refer to in pharmacology?

The term 'efficacy' in pharmacology refers specifically to the ability of a drug to produce a desired therapeutic effect at its target receptor. When assessing a medication, efficacy is an essential concept because it indicates how effectively the drug can activate the receptor and lead to a physiological response. This means that during drug development and clinical use, the efficacy of a medication helps determine its therapeutic potential and effectiveness in treating a condition.

In contrast, selectivity pertains to how specifically a drug targets its receptors, which is crucial but separate from efficacy. The amount of drug required to achieve an effect correlates more with the drug's potency rather than its efficacy. Absorption into systemic circulation relates to bioavailability, which is another important pharmacokinetic property but does not define efficacy. Understanding efficacy is vital for midwifery practice, as it influences treatment choices and patient outcomes.