"Nifedipine" is widely known in medical practice. Often used in cardiology to lower blood pressure. The medication dilates the heart vessels and stimulates blood flow in them. It speeds up the heart rate, therefore it is contraindicated in patients with a frequent pulse. It is a short-acting drug. At the moment, it is rarely prescribed by doctors and only for stopping a hypertensive crisis. It is not used in systematic therapy, here it is replaced by drugs belonging to the long-acting group. Not suitable for all patients Nifedipine. Side effects when taking it occur quite often.
Composition, release form
The drug "Nifedipine" is made in the form of dragees and tablets. Contains the active substance nifedipine.
In dragees, as auxiliary components, milk sugar, wheat starch, talc, microcrystalline cellulose, magnesium stearate, gelatin and sugar coating were used.
The composition of "Nifedipine" in tablets, in addition to the active substance nifedipine, includes:
- magnesium stearate;
- potato starch;
- microcrystalline cellulose;
- lactose monohydrate;
- aerosil;
- povidone.
Tablets and dragees are packed in 10 pieces in aluminum blisters. The package contains 50 pills and instructions for use.
Medicines are stored in a place inaccessible to children and protected from sunlight, at a temperature regime not exceeding 25 ° C. The shelf life of the drugs is 3 years from the date of their manufacture. Do not use medicines after the period indicated on the package.
Pharmacological mechanism of action of Nifedipine
Nifedipine is a calcium antagonist. Refers to 1,4-dihydropyridine derivatives. It is characterized by antihypertensive and antianginal properties. Reduces the flow of calcium ions outside of cellular structures. Acts inside cardiomyocytes, peripheral and coronary arteries.
The drug lowers spasm. Promotes the expansion of peripheral, arterial and coronary vessels. Reduces afterload and reduces myocardial oxygen demand. Increases coronary blood flow. Minus dromo-, foreign- and chronotropic action, which is subsequently blocked by reflex stimulation of the sympathoadrenal apparatus in response to vasodilation of the peripheral system.
During the medication, the renal blood flow rises, which provokes the appearance of moderate natriuresis. The clinical effect occurs 20 minutes after taking the pill. How much is nifedipine? According to the instructions for use, the duration of the clinical effect of the drug is 4-6 hours.
The drug "Nifedipine" is 90% absorbed from the digestive tract. The bioavailability of the drug after taking the tablets is 40-60%. Eating increases the bioavailability of the drug. The medication is characterized by the effect of the "first passage" through the liver organ. The highest concentration of the drug in the blood occurs 1-3 hours after administration and is equal to 65 ng / ml. The drug passes through the placental and blood-brain barriers, is excreted along with breast milk. Has a connection with blood proteins by 90%. 100% split in the liver organ. About 70-80% of the medication taken is excreted in the form of metabolites by the kidneys. The elimination half-life is 2-4 hours. When using "Nifedipine" there is no cumulative effect.
Renal failure in a chronic form of development, peritoneal dialysis, as well as hemodialysis do not affect the pharmacokinetics of the drug. With prolonged use of pills, for 2-3 months, addiction to the drug appears.
Indications for appointment
At what pressure do Nifedipine be taken? Only at high. During the hypertensive crisis. The drug is used for arterial hypertension both in the form of monotherapy, and in complex therapy with other antihypertensive drugs. Indications for use are coronary heart disease, namely, angina pectoris of rest and tension, variant, cardiomyopathy. A medication is used in the treatment of Raynaud's disease.
Contraindications
If you do not take into account contraindications to "Nifedipine", then side effects will not keep you waiting. The instruction for the drug warns that the drug can not be used with hypersensitivity to the substances that make up the drug. With hypersensitivity to dihydropyridine derivatives. The medicine is not prescribed for collapse and cardiogenic shock. The use of myocardial infarction in the acute stage of development, arterial hypotension, cardiac organ failure, and sinus node weakness syndrome are prohibited. The drug is not used in people with severe mitral and aortic stenosis, with tachycardia and subaortic stenosis.
Contraindication to use is pregnancy and the period of breastfeeding. In gynecological practice, medicine is sometimes prescribed to women “in position” as a hypotensive agent. Some doctors prescribe Nifedipine to reduce uterine tone during pregnancy.
"Nifedipine": instructions for use
Reviews (the price of the drug does not reach 50 rubles, which makes the medicine affordable for all segments of the population) note that the medicine works quickly and efficiently, but can cause negative effects.
The dosage of Nifedipine for each patient is selected individually. When choosing it, they rely on the severity of the pathology and on the patient's response to treatment. The medication should be taken with meals or after meals.
The initial dose is 10 mg. Both tablets and tablets are drunk two to three times a day. If the need arises, then a single dosage is increased to 20 mg, these are two tablets or two tablets. The drug in this dosage is drunk once or twice a day. The maximum dose is 40 mg.
In the treatment of people aged and those undergoing combined antihypertensive or antianginal treatment, the dosage can be reduced. This also applies to patients with cerebrovascular accident.
Side effects
In some cases, when using Nifedipine, side effects appear immediately after taking the drug. From the cardiovascular system, this is tachycardia, facial flushing, swelling of the limbs. Some patients experienced a feeling of heat during therapy. A sharp decrease in blood pressure, a short-term loss of consciousness was observed. Worried bouts of angina pectoris.
Side effects "Nifedipine" caused and from the gastrointestinal system. They manifested in the form of dyspeptic disorders, this is constipation, vomiting, diarrhea, nausea. With prolonged use of the drug, malfunctioning of the liver occurred.
In some patients, the medication caused dizziness, pain in the head, drowsiness, poor health, fatigue. Prolonged use can provoke paresthesia and tremor of the extremities.
Side effects of Nifedipine are manifested in the form of myalgia, arthritis, itching of the skin, exanthema, autoimmune hepatitis, urticaria. Patients were concerned about anemia, thrombocytopenia, and leukopenia. During the treatment with "Nifedipine", violations of the urinary system were recorded. Concerned about the flushing of the face, changes in the visual perception of the world, gingival hyperplasia, gynecomastia and hyperglycemia.
special instructions
During therapy with Nifedipine, one should refrain from potentially dangerous activities that require excessive concentration and quick reaction.
When treating with this medication, it is forbidden to drink alcoholic beverages.
Drug Interactions
When used in combination therapy, in combination with other antihypertensive drugs, ranitidine, cimetidine, tricyclic antidepressants and with diuretics, the properties of Nifedipine are enhanced with a decrease in blood pressure.
Nitrates increase tachycardia and hypotensive properties of Nifedipine.
Beta-blockers combined with Nifedipine give a sharp decrease in blood pressure and worsen the condition in heart failure. Combination therapy using the above drugs should be under the supervision of a doctor.
"Nifedipine" is able to reduce the content of quinidine in the blood and increase the amount of theophylline and digoxin in the blood. Because of this, it is necessary to control treatment with the content of the listed drugs.
Rifampicin reduces the properties of Nifedipine. Stimulates the metabolism of the latter. This is due to the influence of liver enzymes.
About overdose
With prolonged use of Nifedipine in large doses, symptoms of an overdose are possible. They appear in the form of a headache, lowering blood pressure, hyperemia of the skin, inhibition of the functions of the sinus node. An overdose can be in the form of arrhythmias and bradycardia.
Treatment of negative symptoms is carried out by washing the stomach. Activated carbon is prescribed. Symptomatic treatment is carried out aimed at normalizing the work of the cardiovascular system.
The antidote of Nifedipine is calcium. Therefore, with symptoms of an overdose, intravenous administration of 10% calcium chloride or calcium gluconate is prescribed.
With a strong decrease in blood pressure, intravenous dobutamine and dopamine are administered. If conductivity has been impaired, injections of isoprenaline and atropine are prescribed. If the condition worsens, with heart failure, intravenous administration of strophanthin is performed.
With poor blood circulation and in life-threatening situations, catecholamines are used in high doses.
Analogs
If for some reason the drug did not fit, then analogues of Nifedipine will help to replace it. The drugs listed below have a similar effect. Many of them allow you to achieve long-term remission and stabilize blood pressure.
The closest analogues of Nifedipine short-acting are the following medicines:
- "Phenigidin";
- Kordafen
- "Nicardia";
- Corinfar
- "Procardia";
- Cordaflex
- Cordipine;
- "Farmadipin".
Substitutes "Nifedipine" can serve as a prolonged action drugs. Among them, such drugs as Nifebene Retard and Cordipin Retard gained popularity. An analogue of long-term exposure is Nifedipine SS, Adalat-SL. Often, to replace Nifedipine, Corinfar Retard and Corinfar Uno are prescribed.
Comparison of Cordipine and Nifedipine
Some patients try to determine which is better: Cordipine or Nifedipine. It is worth noting that both drugs have the same active substance - nifedipine. The composition of the medication differs only in auxiliary substances.
The drugs have exactly the same method of application, similar indications, contraindications and side effects. Differences in manufacturers. Nifedipine is manufactured in Russia, and Cordipine in Slovakia.
“Cordipine retard” contains an increased dose of the active substance, in one tablet - 20 mg, unlike the standard “Cordipine”, which, like Nifedipine, has 10 mg of nifedipine in one pill. This is a long-acting drug. The Corinfar Retard medication has exactly the same effect.
Cost
"Nifedipine" refers to affordable means and has a democratic cost - about 40 rubles for 50 tablets, with a dosage of 10 mg. The drug is well known, and you can buy it at every pharmacy.
Patient Reviews
People say that Nifedipine acts quickly and helps to lower blood pressure in a short time. This is an ambulance drug. It is especially effective in hypertensive crisis. According to patients, the main thing when taking it is to choose the right dosage. The wrong dose can roughly and too much lower the pressure.
Many advise the medicine not to be taken orally, but put under the tongue and dissolve. According to them, the only way the tool helps in full force. Still, after taking the pill, patients recommend lying down for 20 minutes.
Often this drug is prescribed for uterine tone. According to women, he successfully eliminates a similar ailment.
Of the negative aspects, patients note side effects that can cause the use of "Nifedipine." Judging by the reviews, the drug lowers the pressure too much, causes headache and dizziness, hot flashes, excessive sweating, vomiting and nausea. It can provoke the appearance of tachycardia. It gives a short effect. Not suitable for regular use.