Calcium Channel Blocker

Aka: Calcium Channel Blocker

1. See Also
   1. Calcium Channel Blocker Overdose
   2. Dihydropyridine Calcium Channel Blocker (e.g. Amlodipine, Nifedipine)
   3. Non-Dihydropyridine Calcium Channel Blocker (e.g. Diltiazem, Verapamil)
   4. Non-selective Calcium Channel Blocker (e.g. Mibefradil)
2. Mechanism
   1. Cellular channel effects
      1. Effects slow calcium channel activity (blocks voltage-gated L-type calcium channels)
      2. Agents block both calcium and Sodium inflow into cells during action potential phase
      3. Channels present in cardiac and vascular smooth muscle
   2. Calcium Channel Blocker effects
      1. Myocardial relaxation (Non-Dihydropyridines primarily)
      2. Vascular smooth muscle relaxation
      3. Pancreatic B-islet cell inhibition
3. Adverse Effects: Myocardial Infarction
   1. Short Acting Calcium Channel Blockers
      1. Findings
         1. Myocardial Infarction Risk: 60% over Diuretics
         2. Higher dose confers >3x risk of lower dose
      2. References
         1. Psaty (1995) JAMA 274:620-5, 654-5 [PubMed]
         2. Furberg (1995) Circulation 92: 1326-31, 1068-73 [PubMed]
   2. Long acting Calcium Channel Blockers
      1. No increased cardiovascular disease risk
      2. Reference
         1. Alderman (1997) Lancet 349:594-8 [PubMed]
4. Adverse Effects: Bleeding risk
   1. Findings
      1. Higher Incidence of GI Hemorrhage in elderly
      2. Associated with platelet aggregation inhibition
      3. Avoid in older patients if:
         1. Peptic Ulcer Disease
         2. Concurrent Aspirin use
         3. Perioperative
   2. References
      1. Pahor M (1996) Lancet 347:1061-5 [PubMed]
      2. Wagenknecht (1995) BMJ 310(6982):776-7 [PubMed]
      3. Zuccala (1997) BMJ 314:643-4 [PubMed]
5. Adverse Effects: General
   1. Hypotension
   2. Flushing
   3. Nasal congestion
   4. Tachycardia
   5. Dizziness
   6. Nausea
   7. Nervousness
   8. Bowel changes
   9. Eczematous Dermatitis (or other skin reactions)
      1. Occurs in up to 1% of patients on Calcium Channel Blockers
      2. Delayed onset at 3 months after starting Calcium Channel Blockers
      3. Joly (2007) J Invest Dermatol 127(12):2766-71 [PubMed]
6. Types
   1. Dihydropyridine (e.g. Nifedipine)
      1. Primary effects are on peripheral vasculature
   2. Non-Dihydropiridine
      1. Effect both peripheral vasculature and cardiac tissue
      2. Phenylalkamine (Verapamil)
      3. Benzothiazapine (Diltiazem)
7. Protocol
   1. Monotherapy
      1. Diltiazem
      2. Verapamil
   2. Combination with Beta Blocker (Coronary Artery Disease)
      1. Nifedipine
   3. Bradycardia or Left Ventricular Dysfunction
      1. Amlodipine
      2. Felodipine
      3. Isradipine
8. References
   1. Yen (2015) Crit Dec Emerg Med 29(10): 18-23