What can be dangerous about drugs containing nifedipine, which are used to treat hypertension?

Release forms

There are two main forms of release of Nifedipine - tablets and gel-emulsion. Most often, patients are prescribed tablets. They contain a high content of active substance. Gel emulsion is an auxiliary preparation.

Tablets weighing 10 g can be packaged in blisters of 10 pieces each. These blisters are packed in cardboard boxes. Also, tablets of 20 or 50 pieces can be placed in plastic jars.

The gel emulsion is stored in a tube weighing 40 g. This medicine in this form of release is used only for the treatment of hemorrhoids.

There is also Nifedipine in the form of a solution for intravenous injection, as well as in the form of boluses that are injected into the coronary vessels.

Corinfar or Nifedipine: which is better?

An important place in the treatment of cardiovascular pathology and arterial hypertension is occupied by the fast-acting drugs Corinfar and Capoten. These are quite old drugs that have been used for a long time to quickly relieve high blood pressure. However, for long-term and frequent treatment it is better not to use them, since sudden changes in pressure, and even within a short period of time, are dangerous for cerebral circulation disorders, especially in old age. The use of Corinfar normalizes the flow of calcium ions that occurs in various diseases, especially arterial hypertension. Coronary blood flow increases, oxygen content in the myocardium increases, without affecting the venous vessels. There is an increase in renal blood flow.

The main difference between Capoten and Corinfar is in the mechanism of action and is based on the transformation of the hormone angiotensin, which is responsible for regulating the width of the lumen of blood vessels.

After taking Corinfar, the effect is achieved within 20 minutes (sublingually even faster), lasting up to 6 hours. With long-term use (2-3 months), tolerance to the action of the drug develops (the body stops responding to it properly, the effectiveness is greatly or almost completely reduced), so the use of high doses (40 mg or higher) should be avoided during long-term therapy. In general, as already mentioned, Corinfar and Capoten are drugs for emergency action in isolated cases, and their constant use, for example, during crises, is dangerous by provoking strokes. Russian Capoten, which contains the active ingredient captopril, a first-generation ACE inhibitor, is available in tablet form of 25 mg.

How it affects the body

The medicine is a calcium antagonist and belongs to the group of slow calcium channel blockers (SCBC). The substance slows down the process of calcium penetration into the muscle cells of the heart, as well as into the cells of vascular muscles. Under the influence of the drug, the myocardium consumes less oxygen. Nifedipine lowers blood pressure and total peripheral vascular resistance, and the ability of the myocardium to contract is also slightly reduced.

Thanks to the medicine, the tone of the smooth muscles located in the vessels slightly decreases, therefore the peripheral and coronary arteries dilate. Due to this, blood flow in the coronary vessels is normalized. Myocardial conductivity is not inhibited. But you need to remember that Nifedipine does not act against arrhythmia and does not normalize heart rhythm.

Pharmacological properties of the drug Nifedipine

Nifedipine is an antagonist of calcium ions, inhibiting their entry into cardiomyocytes and smooth muscle cells of the coronary and peripheral arteries through slow membrane channels. Dilates coronary and peripheral arterial vessels, reduces myocardial oxygen demand, lowers peripheral vascular resistance and blood pressure. It is quickly absorbed in the digestive tract (when used in the form of a solution or tablets with normal release of the active substance). The maximum concentration in blood plasma when taking conventional dosage forms is achieved after 30–60 minutes. When using various retard forms, the maximum concentration of nifedipine in the blood plasma is observed several hours after oral administration, the duration of action is on average 10–12 hours, for some dosage forms - up to 24 hours.

Indications for use

The doctor prescribes Nifedipine for the treatment of many diseases and pathological conditions:

• angina pectoris, including vasospastic;
• hypertension;
• Raynaud's disease;
• hypertension;
• hypertensive crisis.

Nifedipine is necessary for the prevention and relief of angina attacks, as well as for lowering blood pressure.

The doctor may recommend that the patient take the medicine only once a day. This is due to the fact that Nifedipine is active throughout the day.

For hemorrhoids at any stage up to the 4th stage, the doctor can prescribe Nifedipine gel. This gel dilates blood vessels and normalizes blood flow, which means it will help with rectal bleeding.

Nifedipine for hypertensive crisis

The group of drugs that block calcium channels, which includes Nifedipine, has hypotensive and anti-ischemic properties. The effectiveness of these drugs has been proven in the treatment of primary (essential) hypertension, as well as in the case of renal and endocrine causes of high blood pressure. In this case, conventional dosage forms (solution and tablets) are prescribed to relieve a hypertensive crisis, and prolonged ones are used for long-term therapy. Emergency care for a hypertensive crisis before the ambulance arrives is as follows:

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• The patient should take a semi-sitting position in bed with the help of pillows. This is an important measure to prevent suffocation and difficulty breathing.

• If the patient is already being treated for hypertension, then he needs to take an extraordinary dose of his antihypertensive medication. Remember that the drug will work most effectively if you take it sublingually, that is, dissolve the tablet under the tongue.
• You can take a sedative, such as Corvalol, to normalize the patient’s psycho-emotional state and relieve him of fear, excitability, and anxiety.

Emergency care for a hypertensive crisis is provided, trying to reduce the patient’s blood pressure as quickly as possible so that severe damage to internal organs does not occur.

Instructions for use

The attending physician prescribes an individual dosage to the patient and selects the drug in a suitable release form.

How to take Nifedipine tablets - instructions:

1. At the beginning of the course of treatment, the doctor may prescribe 1 tablet (10 mg) 3-4 times a day.
2. Then it may be necessary to take 2 tablets (20 mg) 3-4 times a day.
3. In severe cases, the dose is increased to 3 tablets (30 mg) 3-4 times a day. This occurs with severe hypertension, as well as with variant angina.
4. In case of an acute attack of angina, it is recommended to take 1-2 tablets (10-20 mg) under the tongue.

An acute attack can be stopped with Nifedipine injections. Within 4–8 hours, injections of 5 mg of the drug are given.

For severe spasms of the coronary arteries, Nifedipine boluses of 100–200 mcg are used. They are injected directly into the vessels (intracoronary). To treat coronary stenosis, boluses of 50–100 mcg are taken.

You must take the medicine strictly in accordance with the recommendations and prescriptions of your doctor. You should not self-medicate, otherwise you can harm your health.

During pregnancy in the second trimester

Pregnancy is a period when a woman becomes more vulnerable as her body is under severe stress. That is why many pregnant women are exposed to various diseases, which may have different etymologies. When treating these ailments, many difficulties arise, since the doctor needs to choose a therapy that will not harm the fetus. This is especially important and difficult. Many drugs have a negative effect on the fetus and are therefore considered prohibited. They try not to prescribe them during pregnancy. Main indications for use during pregnancy:

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• In case of heart disease in the expectant mother, which carries a risk for her and the child.
• Decreased uterine tone.
• High blood pressure.

We have figured out why Nifedipine is prescribed to pregnant women, now we need to consider the instructions for the drug. One should take into account the fact that in some cases doctors independently choose the treatment regimen. They select it based on the characteristics of the patient’s health condition. In most cases, doctors use the regimens that the manufacturer actually suggests in the instructions for the drug. But when prescribing the drug, the doctor always takes into account exactly how far along the girl is.

In the second trimester, the drug is used more actively, since it is already considered conditionally safe. After all, the formation of organs in the fetus in the 2nd trimester is almost complete, so the drug cannot cause the development of pathologies. During this period, the dosage is increased to that used by patients during maintenance therapy - 10 mg per day.

Side effects

The medicine may cause some side symptoms. To relieve them, your doctor may prescribe additional medications.

Side effects:

• increased heart rate;
• skin redness;
• feeling of warmth or heat on the skin;
• hypotension;
• slight swelling;
• skin rash;
• ventricular tachycardia;
• slow heart rate;
• increased attacks of angina pectoris;
• cardiac arrest, asystole;
• heartburn, nausea, diarrhea;
• swelling of the gums;
• liver dysfunction;
• muscle pain;
• headache;
• sleep disorders;
• tremor of the limbs;
• visual disturbances;
• thrombocytopenia;
• leukopenia;
• renal dysfunction;
• increase in the daily amount of urine excreted;
• sudden enlargement of the breast (gynecomastia).

After an intravenous injection, the patient may feel a burning sensation. After intracoronary administration of the drug, within the first minute the patient’s pulse may sharply increase and blood pressure may drop. These unpleasant sensations disappear after 5–15 minutes.

When breastfeeding

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If the pressure has increased suddenly and strongly, you first need to calm down. After counting down five minutes, you need to take another blood pressure measurement on the same arm, and then on the second arm. Has your blood pressure dropped? Call an ambulance. Under no circumstances should you take medications that are not prescribed by your doctor. It's better to wait for the brigade. They will tell you exactly what is possible from pressure during breastfeeding in a particular case. In order for there to be an influx of fresh air, you need to open the window, and then take a comfortable position and move minimally. In case of chills, you should warm your body with a warm blanket or an additional layer of clothing.

Any pills for blood pressure during breastfeeding, along with mother’s milk, release active substances into the baby’s body.

But if the situation is absolutely critical, Methyldopa, Dopegyt, Verapamil are usually prescribed. Before using each drug, you must take herbal tablets: for example, motherwort.

If your blood pressure has increased and your pulse remains no higher than 90/minute, you can take Nifedipine: it is also relatively safe during breastfeeding. A large dosage of any of the drugs listed will pose a danger to the child, so before taking them, consultation with a doctor is required!

Contraindications

There are many contraindications that prohibit the use of this drug for some patients:

• collapse;
• severe form of heart failure;
• hypotension, in which systolic (upper) pressure falls below 90 mmHg;
• cardiogenic shock;
• the first 4 weeks after myocardial infarction (acute period);
• aortic stenosis;
• unstable form of angina;
• lactose intolerance, lactase deficiency;
• GGM syndrome - impaired absorption of glucose and galactose;
• increased individual intolerance;
• lactation period;
• pregnancy less than 20 weeks;
• children's age (up to 18 years).

For these diagnoses and conditions, it is necessary to prescribe other medications to the patient. Nifedipine is not suitable for long-term treatment.

Recently, cardiologists conducted a study in which they proved that Nifedipine increases the risk of sudden cardiac arrest, so this medicine must be taken with extreme caution.

Painkillers

We almost always assign them to ourselves. The most popular antipyretic and pain reliever is paracetamol. Often their temperature is reduced, but they do not look at the maximum allowed daily dose and take it for more than 3 days. As a result, acute toxic liver damage can develop - drug-induced hepatitis, sometimes with severe liver failure.

Painkillers from the group of non-steroidal anti-inflammatory drugs (NSAIDs) - diclofenac, ibuprofen, ketorolac, indomethacin, etc., which are often used to treat headaches, pain in the joints, and spine, should not be taken independently for more than 2-3 days. If the pain does not go away, you should consult a doctor. One of the most common complications is erosive and ulcerative lesions of the gastrointestinal tract. A person took a pill - it didn’t help, took 2-3 without reading the instructions, and developed an ulcer or even worse - bleeding from this ulcer.

In patients with bronchial asthma, taking NSAIDs can provoke asthmatic attacks. NSAIDs, in particular painkillers, reduce the effect of antihypertensive drugs - this should be taken into account by hypertensive patients. All NSAIDs can cause acute drug-induced liver or kidney damage, sometimes severe, although the risk of these complications varies between drugs in this group. In recent years, evidence has emerged that regular use of certain NSAIDs increases the risk of acute myocardial infarction and ischemic stroke.

Carefully

Patients suffering from certain diseases should be extremely attentive to their health. They will have to drink Nifedipine with caution:

• elderly patients;
• hypertrophic obstructive cardiomyopathy;
• severe liver diseases;
• sick sinus syndrome;
• kidney dysfunction;
• mitral valve stenosis;
• chronic heart failure;
• diabetes;
• stenosis of any part of the intestine;
• disturbances in the functioning of cerebral vessels.

Taking the medication in these cases should be strictly under the control and supervision of the attending physician.

Overdose symptoms

You should not take more than 120 mg tablets per day. The maximum dose of intravenous solution is 30 mg.

Signs of overdose:

• a sharp slowdown in heart rate;
• bradyarrhythmia;
• heart rhythm disturbances;
• hypotension;
• collapse;
• cardiogenic shock;
• convulsions;
• loss of consciousness;
• hypoxia;
• acidosis;
• slowing of cardiac conduction;
• hyperglycemia;
• coma.

Symptoms appear 3-4 hours after taking the tablets. In case of overdose, the patient's stomach is washed and activated charcoal is administered. He is then given intravenous injections of atropine with calcium gluconate, calcium chloride and norepinephrine to relieve intoxication. Due to proven ineffectiveness, hemodialysis is not performed.

Interaction with other drugs

Blood pressure drops sharply when Nifedipine is taken simultaneously with other antihypertensive drugs, as well as diuretics, diltiazem, and drugs based on phenothiazine and its derivatives.

Attention and memory may be affected when Nifedipine is used with anticholinergic medications.

This medicine should not be combined with beta-blockers, otherwise severe hypotension and even heart failure may occur.

In combination with magnesium salts, the patient experiences severe muscle weakness.

The effective effect against angina pectoris is enhanced when the drug is combined with nitrates.

Due to the intake of digoxin and theophylline, the amount of these substances in the blood increases.

You should not take Nifedipine together with medications containing calcium. These substances have opposite properties, which reduces their effectiveness. Side effects of the drug are enhanced in combination with fluoxetine and vincristine. Also, the effect of Nifedipine is reduced in combination with rifampicin, so these two drugs are incompatible with each other.

The level of nifedipine in the blood decreases if you take the medicine together with phenytoin, phenobarbital or carbamazepine. Conversely, concentrations increase in combination with itraconazole, cimetidine, fluconazole and ranitidine.

The QT interval on the ECG is prolonged when Nifedipine is taken simultaneously with quinidine. This occurs because the amount of quinidine in the blood decreases sharply, and when it is discontinued, it suddenly increases.

Severe hypotension, dizziness and other unpleasant symptoms occur if the patient drinks Nifedipine and drinks containing ethyl alcohol. This drug should not be combined with grapefruit juice.

During pregnancy in the third trimester

In the course of numerous clinical studies, Nifedipine was classified as a “C” group of drugs. Its use during pregnancy is possible only if there are serious indications from the mother, since the drug can negatively affect the fetus. The drug does not have a teratogenic effect - it does not cause congenital deformities and anomalies in the fetus. Also, scientists have not identified the toxic effect of Nifedipine on the body of the unborn child.

Nifedipine during pregnancy in the third trimester is a risk factor for the development of primary weakness of labor. That is why, if possible, the expectant mother should stop using the drug after 38 weeks of pregnancy. The dosage of the drug in case of threat of spontaneous abortion or premature birth is 10-20 milligrams of Nifedipine per day. This amount of active substance corresponds to half or a whole tablet.

The dose of the active component of the medication for various diseases is selected by the doctor. Usually it is 1-2 tablets per day.

The medicine should be taken with a glass of clean water without gas. Taking grapefruit juice enhances the effect of Nifedipine. The mechanism of action of Nifedipine during pregnancy in the 3rd trimester has been well studied, therefore its interaction has been identified when taken simultaneously with other drugs. Concomitant use of the drug with Rifampicin is prohibited, as it significantly reduces the effectiveness of the drug.

special instructions

Nifedipine should be taken only under the strict supervision of doctors. Elderly patients are advised to reduce the dose. The medicine causes withdrawal symptoms, so it is discontinued gradually. It is necessary to discontinue the drug if the patient experiences chest pain.

If a person has stenosis of two coronary vessels, then the medicine cannot be administered intracoronarily into the third.

During the course of treatment it is forbidden to drink alcohol. It is advisable to refrain from working with machinery, driving a car or other types of transport, and also avoid dangerous work that requires great concentration.

Nasal drops, cough medicines

Many cold medicines contain herbal ingredients. You need to be careful when prescribing such drugs to people with bronchial asthma and other allergic diseases. Quite often, the course of bronchial asthma worsens when taking various herbal antitussives and expectorants. It should also be remembered that antitussive drugs can slow down recovery from acute bronchopulmonary infections - bronchitis, pneumonia: cough suppression inhibits the cleansing of the bronchi from pathogenic microbes. Nasal drops with long-term uncontrolled use can cause atrophy of the nasal mucosa, which can lead to chronic ENT diseases. In addition, in hypertensive patients, uncontrolled use of nasal drops may reduce the effect of antihypertensive drugs, and the pressure may ultimately increase.

Analogs

The following drugs are complete or partial analogues of Nifedipine:

1. "Calcigard Retard".
2. "Cordaflex".
3. "Cordipin Retard."
4. "Kordipin HL".
5. "Corinfar".
6. "Corinfar Retard".
7. "Nifecard HL".
8. "Phenigidine."

The doctor may prescribe these drugs instead of Nifedipine. They have similar properties.