On a concentration-effect curve, the plateau of the effect corresponds to the therapeutic effect.

On a concentration-effect curve, the plateau of the effect corresponds to the therapeutic effect.

• A. True
• B. False
• C. It represents toxic effects exclusively
• D. It represents both therapeutic and toxic effects

Answer: (B)

The plateau on a concentration-effect curve is the maximum effect (Emax) achievable for the specific endpoint being measured. It does not automatically represent the therapeutic effect. If you’re looking at a therapeutic-endpoint curve, the plateau would reflect the highest therapeutic response possible for that endpoint; but you can also have separate curves for toxicity or other effects, each with its own plateau. The key concept is saturation: once receptors or pathways driving that endpoint are fully engaged, increasing concentration no longer increases the response. Because the endpoint in question determines what the plateau represents, a plateau is not inherently the therapeutic effect in all cases.

The plateau on a concentration-effect curve is the maximum effect (Emax) achievable for the specific endpoint being measured. It does not automatically represent the therapeutic effect. If you’re looking at a therapeutic-endpoint curve, the plateau would reflect the highest therapeutic response possible for that endpoint; but you can also have separate curves for toxicity or other effects, each with its own plateau. The key concept is saturation: once receptors or pathways driving that endpoint are fully engaged, increasing concentration no longer increases the response. Because the endpoint in question determines what the plateau represents, a plateau is not inherently the therapeutic effect in all cases.