Calcium channel blockers poisoning

Calcium channel blockers poisoning
Calcium channel blockers (CCBs) are used in the treatment of hypertension, angina pectoris, cardiac arrhythmias. These medications are available in both immediate-release and extended-release preparations, ingestion of sustained release preparations can result in delayed and prolonged toxicity.
Toxicity from organic Calcium channel blockers causes a decrease in mechanical contraction of heart and smooth muscle. Severe toxicity produces hypodynamic shock, characterized by bradycardia and hypotension and often accompanied by metabolic acidosis. Because CCBs interfere with normal signaling of stimulatory agents in the cardiovascular system, standard cardiotonic and vasopressor treatments for hypotension often produce ineffective or minimal effects in patients with severe toxicity.

Pathophysiology:
An increase in intracellular calcium causes smooth and cardiac muscle to contract and accelerates impulse formation in cardiac pacemaker cells. Conversely, a deprivation of intracellular calcium causes smooth muscle relaxation, a decrease in cardiac contraction, and a slowing of automaticity. Clinically, these effects are recognized as hypotension, bradycardia, and shock.