Irreversible agonist

Irreversible agonists are a type of pharmacological agent that bind permanently to their target receptors, causing a sustained activation of the receptor and an irreversible change in the receptor's response. This is in contrast to reversible agonists, which bind temporarily to their target receptors and can be removed to reverse their effects.

Mechanism of Action

Irreversible agonists work by forming a covalent bond with their target receptor. This bond is not easily broken, meaning that the agonist remains bound to the receptor indefinitely. This results in a sustained activation of the receptor, which can lead to a prolonged physiological response.

The mechanism of action of irreversible agonists is different from that of partial agonists and full agonists. Partial agonists only partially activate their target receptors, while full agonists fully activate their target receptors but can be removed to reverse their effects.

Applications

Irreversible agonists have a number of potential applications in medicine. Because they cause a sustained activation of their target receptors, they can be used to produce a long-lasting therapeutic effect. This can be particularly useful in the treatment of chronic conditions, where a sustained therapeutic effect is desirable.

However, the use of irreversible agonists also carries risks. Because they bind permanently to their target receptors, they can potentially cause overactivation of the receptor, leading to adverse effects. This makes the use of irreversible agonists a delicate balancing act between achieving the desired therapeutic effect and avoiding potential adverse effects.

Examples

One example of an irreversible agonist is phenylephrine, which is used as a decongestant and to increase blood pressure. Phenylephrine binds irreversibly to adrenergic receptors, causing a sustained activation of these receptors and a prolonged physiological response.

Another example is isoflurane, an anesthetic that binds irreversibly to GABA receptors, causing a sustained activation of these receptors and a prolonged anesthetic effect.

See Also

• Agonist
• Antagonist
• Inverse agonist
• Allosteric modulator