a anaerobic metabolism drug which acts at the same receptor anaerobic metabolism as that of an agonist, yet produces anaerobic metabolism an opposite effect
a ligand that by binding to a receptor reduces the fraction of receptors in an active conformation, thereby reducing basal activity
in the context of receptors which exert some basic signalling activity even the absence of an agonist (characteristic known as "constitutive activity"), an agent which binds to a receptor, suppressing this activity to some degree.
When an inverse agonist binds to a receptor, it stabilizes the inactive form of the receptor, shifts the equilibrium toward that state and produces a response opposite to that produced by an agonist in the biological system under investigation. These substances possess negative intrinsic activity.
In pharmacology, an inverse agonist is an agent which binds to the same receptor binding-site as an agonist for that receptor but exerts the opposite pharmacological effect. Inverse agonists are effective against certain types of receptors (e.g. certain histamine receptors / GABA receptors) which have intrinsic activity without the acting of a ligand upon them (also referred to as 'constitutive activity'.)