MOA: Calcium channel blockers (CCB) prevent the release of internal calcium stores into the cell cytosol. Heart muscle cell does not respond to calcium ion signal as a result. Therefore, there is a decrease in intercellular calcium. CCB attach to alpha 1 subunit on L-type voltage-gated slow calcium ion channels.
Dosage: 5-10mg (0.075-0.15mg/kg) over 2 min; may give additional 10mg after 30 min if no response.
Onset: 1-3 min IV
Duration: 15 min IV
Half-Life: 3-7 hours
Protein Binding: 90%
Metabolism: Renal 70% Hepatic 15% has an active metabolite (prolong action)
S/E's: Hypotension, flushing, HA, weakness, palpitations, constipation, peripheral edema, myocardial ischemia r/t coronary steal
Uses: Supraventricular tachydysrhythmias (AV node), Vasospastic angina, symptomatic hypertrophic cardiomyopathy; if liver disease (give 20-50% normal dose), geriatrics (give slower IV), DO NOT GIVE WITH: heart failure, severe bradycardia, AV node block, WPW, A fib/flutter, cardiogenic shock, hypotension <90SBP, LV EF <30%, SSS, 2nd or 3rd AV block w/out Pacemaker. CAUTION (pt's treated with digitalis or beta-blockers)