• antidysrythmic, antianginal, antihypertensive
• inhibits movement of Ca ions across cell membranes 
• slow Ca current blocked more important for SA and AV nodes than other tissues in heart
• some selectivity of action
• decreases atrial automaticity, reduces AV nodal refractory period
• depresses myocardial contractility
• reduces vascular smooth muscle tone, dilates coronary arteries and arterioles in normal and ischemic tissues

Onset - 2-5 min

Duration - 30-60 min (up to 4 hr is possible)

PSVT

a-flutter w/ rapid ventricular response

a-fib with rapid ventricualr response

vasospastic and unstable angina

chronic stable angina

hypersensitivity

sick sinus syndrome (unless pt has functioning pacemaker)

2nd or 3rd degree heart block 

sinus bradycardia

hypotension

cardiogenic shock

severe CHF

wolff-parkinson-white with a-fib  or flutter

pts receiving IV beta blockers

wide-complex tachycardias (v tach.s candeteriorate into v-fib when Ca channel blockers are given

dizziness

headache

N+V

hypotension

bradycardia

complex AV block

peripheral edema

• Digoxin - increases serum conc.
• beta adrenergic blockers - may have additive negative inotropic and chronotropic effects
• antihypertensives - may potentiate hypotension

Verapamil - Dosage and Administration

Adult

initial : 2.5 -5 mg slow IV bolus over 2 min

repeat : 5-10 mg in 15-30 min after initial dose, or 5 mg q 15 min until desired response achieved (max 30 mg)

Verapamil - Dosage and administration

pediatric

preg C

monitor vitals

give smaller amounts  (2-4 mg) over longer periods (3-4 min) when treating elderly or when BP is in the lower range of normal

prep to resucitate

AV block or asystole may occur because of slow AV conduction