Calcium channel blockers Flashcards
CCBs used for angina - 6 drugs
Amlodipine Felodipine Nicardipine Nifedipine Diltiazem Verapamil
Diltiazem and verapamil - indications
Hypertension, angina, cardiac arrhythmias
Nimodipine - indications and effects
Subarachnoid hemorrhage: dilates small cerebral vessel, and increases collateral circulation. Reduce neuronal damage.
CCBs available for slow release
Diltiazem, nicardipine, nifedipine, verapamil.
CCBs for immediate release
Amlopidine, felodipine
CCBs - MOA
Block calcium channels in the plasma membrane of smooth muscle and cardiac tissue. Prevents entry of Ca into the cell
Types of Ca channels
L (long) type: found on cardiac tissue, high-voltage channels that are slowly inactivated.
T (transient) type: Low-voltage channels that are rapidly inactivated.
CCBs - adverse effects
Reflex tachycardia (dihydropyridine drugs) Hypotension Gingival hyperplasia Dizziness Flushing Peripheral edema Fatigue Constipation
Diltiazem and verapamil - cardiac effects
Decrease SA node automaticity, cardiac contractility and AV node conduction velocity.
Nimodipine - contraindications
Never given IV: severe hypotension, cardiac arrest, fatalities.
Diltiazem and verapamil - indications
Typical and variant (prinzmetal) angina.
Diltiazem and verapamil - cautions and contraindications
Heart failure (esp verapamil). Digoxin treatment - toxicity
Cardiovascular effect of dihydropyridine CCBs
Coronary blood flow: increase a lot
Heart rate and contractility: no chance/reflex tachycardia.
AV conduction velocity: no change/reflex increase
Cardiovascular effects of diltiazem
Coronary blood flow: increase a lot
Heart rate and contractility: decrease.
AV conduction velocity: decrease
Verapamil - cardiovascular effects
Coronary blood flow: increase a lot
Heart rate and contractility: decrease/big decrease
AV conduction velocity: decrease/big decrease
