Amantidine acts by action of-
**Question:** Amantidine acts by action of-
A. Antagonism of NMDA receptors
B. Antagonism of H1 receptors
C. Antagonism of ACE inhibitors
D. Antagonism of ASIC channels
**Core Concept:** Amantidine is a drug primarily used in the treatment of influenza A and Parkinson's disease. It works by blocking the activity of certain ion channels and receptors in the nervous system and immune cells.
**Why the Correct Answer is Right:** Amantidine primarily acts by blocking the activity of the acid-sensing ion channel (ASIC) type 1, which is involved in pain perception, inflammation, and viral replication. Blocking ASIC channels helps in the treatment of influenza A and Parkinson's disease.
**Why Each Wrong Option is Incorrect:**
A. Antagonism of NMDA (N-methyl-D-aspartate) receptors is incorrect because NMDA receptors are involved in excitatory neurotransmission, and amantidine does not primarily target them.
B. Antagonism of H1 (histamine H1) receptors is also incorrect, as H1 receptors are involved in histamine-mediated responses, and amantidine's primary action is not on these receptors.
C. Antagonism of ACE (Angiotensin-converting enzyme) inhibitors is incorrect because ACE inhibitors are used to treat hypertension and heart failure, while amantidine's primary action is on ASIC channels.
**Clinical Pearl:** Amantidine is a useful drug in the treatment of influenza A and Parkinson's disease due to its ability to block ASIC channels. However, it is essential to understand the correct mechanism of action to avoid confusion with other drugs targeting different receptors or enzymes.
**Correct Answer:** D. Antagonism of ASIC channels
**Explanation:** Amantidine primarily acts by blocking the activity of ASIC (acid-sensing ion channel) type 1. This action is crucial for its use in treating influenza A and Parkinson's disease, where it helps reduce pain, inflammation, and viral replication. Understanding the correct mechanism of action is essential to differentiate amantidine from other drugs targeting different receptors or enzymes, such as NMDA or ACE inhibitors.