Here's a great board question that I don't know if its ever been asked, but can you think why you would want to give glucagon for a beta blocker overdose? Hint: It’s all about cAMP
- Beta blockers at toxic doses would dangerously ↓ HR.
- The heart has β1 receptors which act through a Gs to raise intracellular cAMP
- Glucagon, via its own receptor can ↑ cAMP independently of the blocked β1 receptor
- Also note, that this is an example of physiologic antagonism
- Giving a β1 agonist to overcome the β-block would be an example of competitive antagonism
Can you say, "Gunner Level?"