Calcium Channel Blockers (Calcium Antagonists) Medication for Hypertension

Very effective and well tolerated drugs. They are not the first choice of drugs for the treatment of hypertension because they can increase the risk for other serious health problems. CalciuJ1l antagonists work by affecting the muscle cells around the arteries. These muscle cells contain tiny passages in their membranes called calcium channels. When calcium flows into them, the muscle cells contract and the arteries narrow. Calcium antagonists fill these channels-just like plugs in drains-and prevent calcium from getting into the muscle cells. The drugs don’t, however, affect calcium used in the bone building process. Some calcium antagonists also decrease the heart rate, which further reduces the blood pressure.

Classification

  1. Short Acting: These drugs lower the blood pressure quickly, say in half an hour, but are not long lasting in effect. These are not advocated in the treatment of hypertension as they have to be taken three or four times a day to maintain a sustained effect. Some studies have linked the drugs to increased risk for heart attack, sudden cardiac death and cancer.
  2. Long Acting: These drugs are absorbed into our body more gradually. They take a longer time to lower our blood pressure but have a sustained effect for a longer time.

Various experiments and trials done using long acting calcium antagonist have shown that they are much safer as compared to short acting calcium antagonist.

Long acting calcium antagonists include:

  1. Ampodipine (Ameard, Amlopin, Amlopres)
  2. Diltiazem (Altiazem, Dilcard, Dilzem)
  3. Felodipine (Felogar, Reneial)
  4. IsRadipine
  5. Nicardipine
  6. Nifedipine (Calcigard, Cardilat, Depin)
  7. Verapamil  (Veramil, Verap, Calaptin)

Side Effects

Constipation, headache, rapid heart beats, rash, swelling in feet, lower legs, and gums are some of the important side effects of these drugs. Grape juice should not be taken for about one and a half to two hours before or after taking the pills of nifedipine, felodipine, verapamil as ‘a substance’ in the juice reduces the liver’s ability to eliminate these calcium antagonists from our system allowing the drugs to build up and become toxic.