CCB's (calcium channel blockers) reduce blood pressure.

• Disrupts movement of calcium through calcium channels, thereby:
  • Reducing BP
  • Slowing HR
  • Reducing force of contraction of the heart
• Unlike beta blockers, CCB don't decrease responsiveness of heart to the SNS, hence the baroreceptor reflex. CCB's thus permit better maintenance of blood pressure than beta blockers. However, as a result, the baroreceptor thus increases sympathetic effect, increasing heart rate and contractility
• N-type, L-type, and T-type voltage-dependent calcium channels are present in the zona glomerulosa of the human adrenal, and CCB's can directly influence the biosynthesis of aldosterone in adrenocortical cells, thus influencing the Tx of HTN

• They are particularly effective against large vessel stiffness, one of the common causes of elevated systolic BP in elderly Pt's
• Alter heart rate
• Prevent cerebrovasospasm
• Reduce chest pain caused by angina pectoris

• Dihydropyridine (-dipine, DHP), which are used to reduce systemic vascular resistance and arterial pressure. It includes:
  • Amlodipine (Norvasc), used to lower BP, and prevent chest pain
  • Aranidipine
  • Azelnidipine
  • Barnidipine
  • Benidipine
  • Cilnidipine
  • Clevidipine
  • Isradipine
  • Efonidipine
  • Felodipine
  • Lacidipine
  • Lercanidipine
  • Manidipine
  • Nicardipine
  • Nifedipine (Procardia, Adalat), used as an antianginal (especially Prinzmetal's angina) and as an anti-HTN. It is also used as a tocolytic in preterm labor
  • Nilvadipine
  • Nimodipine
  • Nisoldipine
  • Nitrendipine
  • Pranidipine
• Non-dihydropyridine, including:
  • Phenylalkylamine, which are relatively selective for myocardium, reducing myocardial oxygen demand, and reverse coronary vasospasm, thus often used to Tx angina. It includes:
    • Verapamil (Calan, Isoptin)
    • Gallopamil
    • Fendiline
  • Benzothiazepine, which are an intermediate class between phenylalkylamine and dihydropyridines in their selectivity for vascular calcium channels. By having both cardiac depressant and vasodilator actions, they are able to reduce arterial pressure w/o prdoucing the same degree of reflex cardiac stimulation caused by dihydropyridines. It includes:
    • Diltiazem (Cardizem)
  • Non-selective, including:
    • Mibefradil
    • Bepridil
    • Flunarizine
    • Fluspirilene
    • Fendiline

• Dizziness, headache, redness in the face
• Peripheral edema (i.e. fluid buildup in the legs and ankle)
• Rapid HR, palpitations
• Slow HR
• Constipation
• Gingival overgrowth
• Fatigue, dizziness, sleepiness, nausea, headache
• Stomach pain

Source: http://www.drsfostersmith.com/images/Categoryimages/normal/p-50944-55115P_001.jpg

• Shown to result in marginally significant lower cardiovascular mortality than w/ beta blockers, but they may also have multiple side effects
• POtential major risks are mainly associated w/ short-acting CCB's

• HTN
• Beta blocker