Nifedipine - instructions for use, dose, side effects, contraindications

The drug is a calcium channel blocker Ltype of smooth muscle cells and cardiomyocytes. The decrease in calcium intake causes antianginal, hypotensive action. The drug lowers the tone of the vessels, expands the coronary arteries, reduces the afterload on the heart and reduces the need for the heart in oxygen.

Pharmacokinetics:

Quickly and completely absorbed from the gastrointestinal tract, metabolized by the liver. Bioavailability of 45-70% (increases with cirrhosis of the liver, in elderly patients). The connection with plasma proteins is 92-98%. After oral administration, the maximum concentration in the plasma is created after 30 minutes, the half-life is 2-4 hours. intravenous the half-life period is 3.6 hours.

About 80% is excreted by the kidneys in the form of inactive metabolites and about 15% - with feces.

Indications:

Cupping and prevention of angina attacks (including angina, prinzmetal angina), hypertrophic cardiomyopathy (obstructive, etc.), Raynaud's disease, hypertensive crises, essential hypertension, pulmonary hypertension, bronchial obstructive syndrome.

ICD-10

IX.I10-I15.I10 Essential [primary] hypertension

IX.I10-I15.I15 Secondary Hypertension

IX.I20-I25.I20 Angina pectoris [angina pectoris]

IX.I20-I25.I20.1 Angina with documented spasm

IX.I26-I28.I27 Other forms of pulmonary heart disease

IX.I30-I52.I42 Cardiomyopathy

IX.I70-I79.I73.0 Raynaud's syndrome

Contraindications:

Cardiogenic shock, acute myocardial infarction (first 8 days), collapse, hypotension, hypersensitivity, severe heart failure, severe aortic stenosis, idiopathic hypertrophic subaortal stenosis, pregnancy, lactation, children's age.

Carefully:

Stenosis of the aorta / mitral valve mouth, severe tachycardia or bradycardia, hypertrophic obstructive cardiomyopathy, hepatic / renal failure, age under 18, elderly. Atrioventricular blockade of II and III degree; syndrome of weakness of the sinus node; malignant hypertension; hypovolemia. Esophageal obstruction, intestinal obstruction or narrowing of the lumen GIT in the anamnesis; permanent valve stoma with reservoir (Cock's pocket) on the ileum after total proctocolectomy; inflammatory bowel disease; Crohn's disease, severe disorders of cerebral circulation, myocardial infarction with left ventricular failure, hemodialysis (due to the risk of arterial hypotension); pregnancy (II and III trimesters); simultaneous reception of beta-adrenoblockers, digoxin.

Pregnancy and lactation:

Category FDA - C. The drug is excreted in breast milk. Nifedipine is not recommended during pregnancy and lactation, as experimental studies have shown the teratogenic effect of nifedipine.

Dosing and Administration:

The drug should be taken before or after meals, taking the drug while eating slows down absorption. Dosing regimen is individual. The initial dose on average is 10 mg 3-4 times a day. If necessary, the dose may be increased to 20 mg 3-4 times a day.

For relief of hypertensive crisis or an attack of angina pectoris - 10-20 mg sublingually.

With intravenous administration for cupping an attack of angina pectoris - 5 mg for 4-8 hours.

For relief of acute spasms of the coronary arteries - intracoronary bolus 100-200 mcg, with stenosis of the coronary vessels - 50-100 mcg.

The maximum daily dose is 120 mg, 30 mg intravenously.

Side effects:

On the part of the digestive system: gingival hyperplasia, nausea, vomiting, diarrhea, heartburn, decreased liver function, dyspepsia, decreased activity of hepatic transaminases, cholestasis.

From the cardiovascular system: arterial hypotension, face hyperemia, a feeling of heat, ventricular tachycardia, peripheral edema, bradycardia, increased attacks of angina, asystole.

From the hemopoietic system: thrombocytopenia, leukopenia, anemia.

From the side of the nervous system: headache, dizziness, muscle pain, paresthesia, light vision disorders, tremors, sleep disturbances.

On the part of the urinary system: a violation of kidney function, an increase in daily diuresis.

On the part of the endocrine system: gynecomastia, hyperglycemia.

Other: allergic reactions, hives, itching, local burning and redness at the injection site, increased heart rate.

Overdose:

Hyperemia of the facial skin, headache, lowering of arterial pressure, tachycardia, suppression of sinus node function, bradyarrhythmia.

When taking a large number of retard-tablets, signs of intoxication appear no earlier than 3-4 hours and can additionally be expressed in loss of consciousness, including coma, cardiogenic shock, convulsions, hyperglycemia, metabolic acidosis, hypoxia.

Treatment - gastric lavage, Activated carbon. Intravenous the administration of norepinephrine, calcium chloride (10% solution) or calcium gluconate in the solution of atropine (intravenously). With the development of heart failure - intravenous strophanthin. Hemodialysis is ineffective.

Interaction:

The antihypertensive effect of the drug is increased by diuretics, antihypertensive drugs, phenothiazine derivatives, tricyclic antidepressants, diltiazem, cimetidine, ranitidine.

Impaired memory and attention in elderly patients with simultaneous reception with anticholinergic drugs.

Increases the bioavailability of cephalosporins (cefixime).

Development of arterial hypotension / heart failure with simultaneous admission with beta-blockers.

Strengthening of the antianginal effect of the drug with simultaneous administration with nitrates.

Quinidine - a decrease in the concentration of quinidine in the blood plasma.

Calcium preparations decrease the effectiveness of the drug.

Muscle weakness with simultaneous admission with magnesium preparations.

Fluconazole and itraconazole slow the excretion of the drug from the body.

The drug increases the concentration of theophylline and digoxin in the blood plasma.

Reducing the concentration of the drug in the blood while taking with phenytoin, fenoarbital, carbamazepine, rifampicin.

Diltiazem slows down the metabolism (a reduction in the dose of nifedipine is required).

Increased side effect of the drug with simultaneous reception with fluoxetine.

Ethanol enhances the effect of the drug, which can lead to dizziness.

Special instructions:

You should refrain from drinking alcohol.

Elderly patients are advised to reduce the daily dose (reduced metabolism).

It is not recommended to use short-acting drugs for long-term treatment of angina pectorisor hypertension, since it is possible to develop unpredictable changes HELL and reflex angina.

In patients with stable angina at the beginning of treatment, paradoxical enhancement of anginal pain may occur, with severe coronarosclerosis and unstable angina pectoris - aggravation of myocardial ischemia

Cancel the drug should be gradual (possibly the development of withdrawal syndrome).

Impact on the ability to drive vehicles and manage mechanisms

When taking the drug should be abandoned driving vehicles or management mechanisms.

Instructions

Nifedipine (Nifedipinum)