NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents Example 1

NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents Example 1

A full agonist induces a conformational change that turns on signal transduction to the full extent. A partial agonist acts, to a lesser extent, somewhat like an agonist. An antagonist brings about a conformational change that stabilizes the receptor in the baseline state, rendering it “silent.” When agonists or partial agonists are present, the antagonist makes the receptor revert to the baseline state, leading to a reversal in their actions. On the other hand, an inverse agonist causes a conformational change that stops all activities, including the baseline actions (Stahl, 2021). The functionality of the inverse and partial agonists may influence the efficacy of psychopharmacologic treatments, as they may produce less or opposite effects when compared with full agonists.

1. Compare and contrast the actions of g couple proteins and ion-gated channels.

G couple proteins (GPCR) are a family of transmembrane receptors that lead to the activation of signaling pathways through the G proteins. The activation of the downstream signaling pathways is brought on by the binding of the ligand to a GPCR that then activates the G protein (Stahl, 2021). On the other hand, the ion-gated channels, transmembrane proteins, allow the passage of ions through the membrane when a ligand binds with a receptor. The binding of a ligand to an ion-gated receptor leads to a conformational change that opens the channels, causing ions to flow through it.

The critical distinction between the g couple proteins and the ion-gated channels is the speed of their action; GPCRs lead to the activation of signaling pathways that only take seconds to minutes to lead to a response, while ion-gated channels take milliseconds to respond. Another distinction is the type of signaling pathway that is activated by each of them. The GPCRs lead to the activation of the intracellular signaling pathways that influence changes in gene expression; on the other hand, the ion-gated channels directly affect membrane potential changes. Despite these differences, ion-gated channels and GPCRs are vital targets for most psychopharmacologic agents. For many drugs to modulate intracellular signaling pathways, they must act on GPCRs, while others work on the ion-gated channels to modulate the excitability of neurons and membrane potential.

1. Explain how the role of epigenetics may contribute to pharmacologic action.

Epigenetics refers to how gene expression occurs without changes to the underlying DNA sequences. Several factors can influence these changes, such as pharmacologic agents, stress, and environmental exposures (Stahl, 2021). Pharmacologic agents can alter the activity of the enzymes that act on DNA and histones, the proteins that package the DNA to a composite structure, thus influencing epigenetics. For instance, some drugs that add methyl groups to the underlying DNA can cause gene expression changes, while some medications that cause the removal of ethyl groups from the histones can also lead to these changes. Changes in epigenetics can influence some drugs’ pharmacologic actions by altering the genes involved with their mechanism of action (Stahl, 2021). For example, the drugs that target the receptor may alter the expression of the downstream genes of the receptor, causing neuronal function changes. Epigenetics has also been associated with the development of tolerance or dependence on certain drugs.

1. Explain how this information may impact the way you prescribe medications to patients. Include a specific example of a situation or case with a patient in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.