- How do calcium antagonists work?
- Calcium channel blockers - division into groups
- Applicationcalcium blockers
- Calcium channel blockers: indications
- Calcium channel blockers: contraindications
- Calcium antagonists: side effects
- Recommendations for patients using calcium channel blockers
- Calcium antagonists: interactions
Calcium channel blockers, in other words calcium antagonists, belong to a group of drugs widely used in cardiology. They are used by patients with arterial hypertension, patients with cardiac arrhythmias, ischemic disease and other cardiovascular diseases. What should I know about them?
Calcium channel blockers , otherwisecalcium antagonists , are drugs that are especially often used when heart disease is accompanied by diabetes, chronic bronchitis or Asthma, as these drugs have no effect on other organs and, for example, do not affect blood glucose levels.
How do calcium antagonists work?
Calcium channel blockers reduce the amount of calcium ions that enter the muscle cells. Calcium is necessary for cell contraction, so when its inflow is blocked, the cell relaxes.
Calcium channel blockers - division into groups
In terms of action and chemical structure, calcium antagonists can be divided into two groups:
- Dihydropyridine (DHP) derivatives - act not on the heart, but on the blood vessels, leading to their dilatation. The DHP drugs include: nitrendipine, isradipine, nifedipine, amlodipine, lacidipine, felodipine.
- Non-Hydropyridine Derivatives (NDHP) - work on the heart by reducing the strength and frequency of contractions. It also reduces the amount of blood that the heart ejects into the arteries. NDHP drugs include: diltiazem (a benzothiazepine derivative), verapamil (a phenylalkylamine derivative).
Both of these groups act on the arteries and cause them to relax, and thus - blood flow with less resistance. This in turn obviously reduces blood pressure.
The currently used preparations are almost exclusively new generation drugs. They are characterized by a steady and distributed release of the active substance, which is why usually 1 tablet a day is enough instead of 3, which makes it convenient to use, which is important, for example, for the elderly.
They do not cause a sudden drop in pressure, which increases the safety of their use.
The likelihood of side effects is also lower as the drug is released in equal doses.
Applicationcalcium blockers
Calcium antagonists are drugs most often used in patients who, in addition to arterial hypertension, suffer from coexisting physiological conditions or diseases, e.g.
- atherosclerosis of peripheral arteries (carotid, lower limb arteries)
- left ventricular hypertrophy
- some cardiac arrhythmias
- ischemic heart disease
- diabetes
- when the patient is over 60
- in pregnant women
Calcium channel blockers: indications
- hypertension
- heart rhythm disturbance
- coronary artery disease
Calcium channel blockers: contraindications
The most important contraindications to the use of verapamil and diltiazem are:
- heart failure
- blood pressure too low
- AV block
- bradycardia
In the case of using other calcium antagonists, the most important contraindications are:
- hypotension
- heart failure
- cardiomyopathy
- acute coronary syndrome
- significant aortic stenosis
Calcium antagonists: side effects
- swelling, mainly of the feet
- slow heart rate
- headaches
- constipation
- drop in blood pressure
- symptoms of allergy to the active ingredient, e.g. rash
Recommendations for patients using calcium channel blockers
Like all antihypertensive drugs, calcium channel blockers can cause hypotension, this may be due to your individual predisposition and reaction, or interaction with other drugs taken at the same time.
This is why you need to remember to systematically take blood pressure measurements when using calcium antagonists, as well as measure blood pressure when you feel worse.
During treatment, you must not discontinue these medications, change doses, take preparations prescribed for someone else, and in the case of too high or too low values of the measured pressure, contact your doctor immediately.
Patients are also advised not to consume large amounts of grapefruit juice, which is a vegetable flavonoid concentrate, while using calcium antagonists.
The mechanism of action of these compounds is based on the inhibition of one of the enzymes responsible for the first phase of metabolism of many drugs - thus contributing to a significant increase in its concentration in the blood, and consequently to the effects ofundesirable.
Failure to follow this recommendation may lead to even several-fold increase in the concentration of the drug from the group of calcium antagonists in the blood. This, in turn, may cause a dangerous drop in blood pressure, dizziness and fainting, which may be life-threatening.
Calcium antagonists: interactions
Taking calcium antagonists with drugs such as itraconazole, erythromycin, ketoconazole increases the concentration of calcium channel antagonists in the blood, which increases the risk of side effects.
The use of phenobarbital or rifampicin together with calcium channel blockers, on the other hand, causes a decrease in the concentration of these drugs in the blood, which in turn reduces or completely eliminates the effects of drugs and ineffective treatment.
Using verapamil or diltiazem with amiodarone (an anti-arrhythmic drug) carries a risk of severe bradycardia, which is an excessively slow heart rate, which can be life-threatening.
Taking diltiazem or verapamil with beta-blockers may cause: a significant drop in blood pressure, severe heart failure or asystole - no electrical activity of the heart.
It should be remembered that discontinuation or changes in the dosage of all taken medications is determined by the doctor. It makes decisions based on the patient's predispositions, comorbidities and interactions with medications that the patient is already taking. In the event of any disturbing symptoms, the patient has the right to consult a doctor at any time.
You should also consider your diet and lifestyle while treating high blood pressure. In addition to pharmacological treatment, it is worth introducing a diet rich in vegetables and fish, limiting the consumption of s alt and alcohol, introducing permanent physical activity, stopping smoking, and taking care of rest and relaxation.