Week 7: Calcium Channel Blockers Flashcards
Dihydropyridine - Nifedipine (Procardia) and Amlodipine (Norvasc) MOA
- inhibit calcium ions from entering cell membranes in the peripheral vascular system - no effect on the heart - causes vasodilation - relaxes the smooth muscles (directly affects muscle tone) - makes vessels more leaky
Dihydropyridines cautions/contraindications
- Never use in patients with heart failure/edema
- Ok to use in pregnancy
- avoid in unstable angina
Dihydropyridine ADRs
- Headache
- Edema
- 1st dose effect: flushing, dizziness, H/A, hypotension, reflex tachycardia
Why are calcium channel blockers (and possibly ARBs) more appropriate HTN drugs to use in African American patients?
African Americans:
- have less angiotensin II
- RAAS system is not as efficient
- have higher levels of intracellular calcium
- have a higher risk for angioedema
Non-Dihydropyridine - Verapamil & Diltiazem (Cardizem) MOA
Inhibit calcium ions from entering the cell membranes - affect the smooth muscle in the heart - has a highly negative ionotropic effect and slightly negative chronotropic effect
Also affects smooth muscle in the GI tract, which can lead to decreased peristalsis
Non-Dihydropyridines Indications for use
- HTN in the presence of arrhythmia (Afib/SVT) - CAD/Angina - not used for HTN alone - class 4 antiarrhythmic because of its ionotropic and chronotropic effects
Non-dihydropyridine (Verapamil/Diltiazem) cautions/ contraindications
- avoid use in heart failure/edema
- avoid in ventricular dysfunction and in SA/AV nodal conduction disturbances
- contraindicated in pts with SBP less than 90mmHg
- avoid in pregnancy and lactation
Dihydropyridine and Non-Dihydropyridine ADRs
- edema
- headache
- gingival hyperplasia
- constipation (non-dihydropyridines)
Verapamil/Diltiazem Patient Education:
- avoid NSAIDS, alcohol use, being in a jacuzzi alone
- GI reflux disease symptoms can get worse after starting this medication
