How do calcium antagonists work?
Calcium antagonists block the flow of calcium to the muscle cells located in the heart and arteries, causing the muscle fibers to relax, the vessels to expand, leading to a decrease in blood pressure.
What are the different types of calcium antagonists?
All calcium antagonists can be divided into 3 groups depending on their structure.
The first group includes nifedipine, amlodipine, felodipine, lacidipine, and isradipine. These drugs act mainly on blood vessels and somewhat accelerate the pulse (increase the heart rate).
The second group includes verapamil, which acts mainly on the heart and to a lesser extent on the vessels, gives an antiarrhythmic effect and reduces the pulse.
The representative of the third group is diltiazem, which equally affects the blood vessels and the heart and somewhat reduces the pulse.
When selecting a drug, the doctor takes these features into account. For example, if you usually have a rare pulse (a tendency to bradycardia), then from the calcium antagonists, nifedipine, amlodipine, felodipine will suit You. With a tendency to tachycardia, verapamil or diltiazem is usually prescribed.
The first calcium antagonists appeared in the 60s – nifedipine, verapamil, diltiazem (they are called first-generation drugs) and remain important to this day. These drugs have a number of disadvantages (short duration of action with the need to take 3-4 times a day, relatively frequent development of adverse reactions). These disadvantages are almost devoid of more modern (but also more expensive) calcium antagonists of the second and third generation, such as amlodipine, felodipine, lacidipine, isradipine.
Calcium antagonists of the first generation received a “new life” due to the creation of long-acting medicinal forms based on them with high efficiency and relatively low cost. These drugs include nifedipine-retard and verapamil-retard, diltiazem-retard.
The word “retard”, as well as the designation SR, ER, LP after the name of the drug means that it is a long-acting drug (it can be taken 1-2 times a day).
Is it true that nifedipine adversely affects the heart?
Indeed, in the last decade, a number of publications have appeared in the scientific literature about the negative impact of nifedipine on life expectancy. These data are primarily due to the short action of nifedipine (4-6 hours) and associated sharp fluctuations in blood PRESSURE.
Modern medicinal forms, in particular nifedipine-retard, act up to 12 hours and are devoid of negative properties. They can be recommended for long-term treatment of hypertension.
Short-acting nifedipine retains its value only as an emergency medicine and is not recommended for permanent treatment.
What’s good about the calcium antagonists?
Calcium antagonists effectively reduce blood pressure, rarely give side effects, suspend the progression of atherosclerosis, do not have an adverse effect on carbohydrate and fat metabolism, cause the reverse development of changes in the cardiovascular system due to hypertension. Perhaps the only drawback of calcium antagonists is their relatively high cost.
In which cases does the doctor prescribe calcium antagonists?
Calcium antagonists have an advantage in elderly patients with a combination of hypertension and coronary heart disease. Since calcium antagonists dilate blood vessels, they are successfully used for atherosclerosis of the vessels of the lower extremities.
When can I not prescribe calcium antagonists?
Verapamil and diltiazem are not recommended for severe heart rate reduction (less than 55 per minute), some cardiac conduction disorders. Nifedipine should not be taken with a tendency to tachycardia (pulse rate more than 80 per minute). Calcium antagonists of the second and third generations practically do not affect the pulse rate.
Be sure to inform your doctor:
Whether you have taken calcium antagonists before, how You reacted to them.
How should I take calcium channel blockers?
Calcium antagonists are taken during meals or between meals, with a small amount of water.
What adverse (side) effects are possible when taking calcium antagonists?
Of the side effects of calcium antagonists, the most common are swelling of the ankles and lower shins. These symptoms are more pronounced if there were injuries to the lower extremities or there is a disease of the veins. Another side effect of calcium antagonists (it concerns mainly nifedipine and other drugs of the first group) – rapid heartbeat, sudden appearance of a feeling of heat, redness of the skin of the face and neck, headache. These phenomena are reduced when taking the drug after a meal. When taking verapamil, constipation is occasionally noted. The appearance of these adverse reactions should be reported to the doctor.