Ltypeblockerare

Ltypeblockerare are pharmacological agents that inhibit L-type voltage-gated calcium channels (Cav1.x), thereby reducing calcium influx into cardiac and smooth muscle cells. The name L-type reflects the long-lasting calcium currents first described in muscle tissue.

Mechanism and effect: By blocking Cav1.x channels, these compounds decrease intracellular calcium, promoting relaxation of vascular smooth muscle and reducing cardiac contractility. In the heart, they can also slow conduction through the atrioventricular node, particularly with non-dihydropyridine agents, which affects heart rate and rhythm.

Classification and examples: The main subclasses are dihydropyridines (such as amlodipine, nifedipine, felodipine), which primarily produce peripheral vasodilation; and non-dihydropyridines (verapamil, diltiazem), which have more pronounced effects on the heart. There are other agents with L-type blocking activity, but these two groups are the most clinically used.

Clinical use: Ltypeblockerare are used to treat hypertension, chronic stable angina, and certain arrhythmias. Dihydropyridines are typically chosen for blood pressure control and angina relief, while non-dihydropyridines are selected when both rate control and symptom relief are desired.

Side effects and cautions: Common adverse effects include edema, headache, flushing, and palpitations. Verapamil and diltiazem can cause bradycardia or AV block; constipation is notably associated with verapamil. Cautions include potential interactions with beta-blockers and other antihypertensives, hepatic metabolism considerations, and, in some contexts, reduced tolerance in heart failure with reduced ejection fraction depending on the agent used.

See also: calcium channel blockers; Cav1.x channels; cardiovascular pharmacology.