Predominant mechanism for succinylcholine-induced tachycardia in adults?

Predominant mechanism for succinylcholine-induced tachycardia in adults?

• A. Histamine release from mast cells
• B. Stimulation of nicotinic receptors at autonomic ganglia
• C. Blockade of nicotinic receptors at autonomic ganglia
• D. Direct vagolytic effect at postjunctional muscarinic receptors

Answer: (B)

Predominant tachycardia with succinylcholine in adults comes from stimulation of nicotinic receptors at autonomic ganglia. Succinylcholine can activate these ganglionic receptors (Nn), increasing sympathetic outflow and raising heart rate. Histamine release from mast cells is not the main driver here and would more likely contribute to other effects like hypotension in some cases. Blocking autonomic ganglia would tend to blunt sympathetic responses and isn’t the mechanism producing tachycardia. Direct vagolytic effects on postjunctional muscarinic receptors are not the primary action of this drug.

Predominant tachycardia with succinylcholine in adults comes from stimulation of nicotinic receptors at autonomic ganglia. Succinylcholine can activate these ganglionic receptors (Nn), increasing sympathetic outflow and raising heart rate. Histamine release from mast cells is not the main driver here and would more likely contribute to other effects like hypotension in some cases. Blocking autonomic ganglia would tend to blunt sympathetic responses and isn’t the mechanism producing tachycardia. Direct vagolytic effects on postjunctional muscarinic receptors are not the primary action of this drug.