Peptides MEX / Glossary
Efficacy: maximal response and clinical meaning
Efficacy has a different scope in a receptor assay and in a clinical study.
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Efficacy on a response curve
In receptor pharmacology, efficacy concerns the response a compound can produce in the tested system. The observed maximum is often described as Emax. Potency instead compares how much is needed to achieve a defined effect.
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From an assay to a clinical outcome
Two curves may reach different heights even when one is shifted toward lower concentrations. This illustrates why potency and efficacy are not interchangeable. Clinical efficacy requires results in a study context; a cellular maximum does not establish it.
Sources: [1]
Questions about this reference
Does greater potency mean greater efficacy?
No. A lower concentration for a given effect does not guarantee a larger maximal response.
Sources and original reading
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