Dosis-Responsrelatie: Potentie en Werkzaamheid

Potency refers to the amount of drug required to generate a biological response.

In the dose–response curve of two antihypertensive drugs, candesartan and irbesartan, a lower EC₅₀ value of candesartan suggests higher potency. This means that a lower dose of candesartan achieves the desired effect compared to irbesartan, which requires a higher dose.

However, since their E_max values are similar, both drugs are equally efficacious.

The efficacy of a drug depends on the number of drug–receptor complexes formed and the extent of receptor activation.

Maximal efficacy implies that the drugs occupy all receptors, and further increasing the drug concentration does not lead to an additional response.

Full agonists have high efficacy because they completely activate the receptors, triggering a full response.

In contrast, partial agonists exhibit lower efficacy as they activate the receptors to a lesser extent.

On the other hand, antagonists have zero efficacy. They do not activate the receptors but instead act as blockers. They reduce the number of available receptors for agonist binding or alter the receptor conformation, preventing effective agonist binding.