How would the use of certain diuretics (loop and thiazides) potentiate the toxicity of antiarrhythmic drugs?
Loop diuretics inhibit reabsorption in the ascending loop of Henle of Na+/K+/Cl-, which causes water, Na, Cl, K, and Ca+2 to be excreted. Antiarrhythmic drugs function as Na+ channel blockers or Ca+2 blockers, or K+ blockers. The massive excretion by a potent diuretic and the blocking of channels can cause electrolyte imbalances and arrhythmias and frequency dependent block. where the drug gets in when the channel is open.
