2023-06-01 09:25:03
THE calcium channel blockers (ca) also called calcium antagonists are a class of drugs that slow down the entry of calcium in the muscle cells of the blood vessels and the heart. These molecules acting at the level of calcium channels cause a arterial vasodilation (increase in the caliber of the arteries). This effect optimizes theheart oxygenation and limits the rise in blood pressure.
Calcium channel blockers are mainly indicated in the treatment of high blood pressure (hta) associated or not with one or more cardiac pathologies. They can also be prescribed as a second intention in case ofcoronary insufficiency. Finally, they are indicated to improve certain heart rhythm disorders.
Be careful, in no case do these drugs alter the binding of calcium to the bones.
What is the best calcium channel blocker (ca) or calcium antagonist?
It exists different types of calcium channel blockers. There is no more effective calcium channel blocker than another. The choice of calcium channel blocker is made by the doctor according to the effect on heart rate.
Non-bradycardiac calcium channel blockers (dihydropyridines)
Non-bradycardiac calcium channel blockers of the dihydropyridine class do not slow the heart rate and have a predominant vascular effect.
To treat isolated hypertension, inhibitors with a tachycardic effect (increasing the heart rate) are often given (nifedipine, nicardipine…).
When hypertension is associated with coronary artery disease (and angina pectoris or angina), drugs that do not affect heart rhythm (neutral) are preferred (amlodipine, felodipine, isradipine…).
Bradycardiac calcium channel blockers (verapamil, diltiazem, etc.)
To treat high blood pressure associated with angina or heart rhythm disorders, the doctor tends to prescribe bradycardiac calcium channel blockers Who slow heart rate (diltiazem, verapamil…).
List of calcium channel blockers
Non-bradycardiac calcium antagonists of the dihydropyridine class:
- Amlodipine (Amlor®)
- Felodipine (Flodil®)
- Isradipine (Ijaz®)
- Nicardipine (Loxen®)
- Lercanidipine (Lercan®, Zanidip®)
- Nifedipine (Adalate®)
- Nitrendipine (Nidrel®)
- Manidipine (Iperten®)
- Clévipidine (Cleviprex®)
Bradycardiac calcium channel blockers:
- Blood apamil (Isoptine®)
- Diltiazem (Bi-Tildiem®, Mono-Tildiem®, Tildiem®)
Calcium channel blockers are treatments administered by orally. Some of them exist in intravenous form (Loxen®, Isoptine®, Tildiem®).
What is the mechanism of action of calcium channel blockers?
Calcium channel blockers act at the level of voltage-gated calcium channels by slowing down the entry of calcium into vascular smooth muscle cells and cardiomyocytes (contractile cells that make up heart muscle).
They have different effects on heart cells such as the decrease in the force of contraction of the myocardium. They also induce arterial vasodilation, which optimizes the oxygen supply to the heart.
Indications: when to take calcium channel blockers?
- Calcium channel blockers are mainly indicated in the treatment of arterial hypertension.
- These drugs can also be prescribed as a second-line treatment in the event of coronary insufficiency.
- Finally, they are indicated to improve certain heart rhythm disorders.
Anti-hypertensives (treatment of hypertension, high blood pressure)
Calcium channel blockers are first-line drugs for high blood pressure.
Some medical contexts are all the more favorable to the use of calcium channel blockers to treat arterial hypertension in first intention such as angina pectoris or certain cardiac arrhythmias.
Medications effective once morest certain heart disorders
Calcium channel blockers can also be used second-line in disease-modifying treatment of coronary insufficiency (associated with a angina) in case of inefficiency or contraindications to beta-blockers.
Finally, some calcium channel blockers can be prescribed to treat certain heart rhythm disorders (paroxysmal supraventricular tachycardia, junctional tachycardia (Bouveret’s disease), atrial fibrillation, ventricular arrhythmias, etc.).
Calcium channel blockers are not effective drugs forheart failure. However, some of them can be used when heart failure is associated with myocardial ischemia or arterial hypertension.
Calcium channel blockers: what are the side effects of these blood pressure medications?
Like all medicines, calcium channel blockers can cause certain side effects such as:
- alow blood pressure(risk of orthostatic hypotension, fatigue, weakness, dizziness, malaise or syncope);
- a constipation ;
- and slow heart rate (bradycardia) ;
- of the lower limb edema. Diuretics are ineffective once morest these edemas which are not the consequence of water retention. These are not serious. However, if they affect the quality of life, it is recommended to consult your doctor so that the latter may modify the treatment.
- of the headache (headaches) ;
- of the hot flashes associated with redness of the face (flush) ;
- more rarely: palpitations, hives, sleep disturbances, nausea, stomach pain…
These side effects may occur at the start of treatment or followingwards.
Note that it is preferable to take calcium channel blockers with meals in order to limit digestive side effects. The dosage must be respected (risk of intoxication by overdose).
What are the contraindications of calcium channel blockers?
There are few contraindications to these drugs. However, they are generally not prescribed in case of:
- significant bradycardia ;
- certain heart conditions (unaided atrioventricular block, left ventricular failure, poorly controlled heart failure, etc.);
- low blood pressure.
The pregnancy is not a contraindication to taking a calcium channel blocker. However, the treatment of hypertension in pregnancy absolutely requires medical and obstetric monitoring.
There are certain risks of drug interaction with the following treatments: dantrolene, St. John’s wort, ergot derivatives and torsadogen drugs. In addition, it is better to avoid the combinations: Nifedipine + Diltiazem and Ivabradine + Diltiazem.
Calcium channel blockers are drugs only available on medical prescription. Under no circumstances should they be taken as self-medication.
Medical monitoring (including blood pressure and heart rate) should be required throughout treatment.
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