Mechanism of action
A selective class II Calcium channel blocker derived from dihydropyridine. Causes antianginal and hypotensive effects. Relaxes vascular smooth muscle. Cures spasm and dilates coronary and peripheral arteries. Reduces peripheral resistance and slightly - the contractility of the myocardium, reduces the afterload on the heart and the myocardial need for oxygen. Improves coronary blood flow, poststenotic circulation in atherosclerotic obstructions.
Does not inhibit automatism and myocardial conductivity, may cause reflex tachycardia.
Suction
Quickly and almost completely (90-100%) is absorbed from the gastrointestinal tract. Systemic bioavailability is 50-70%.
Distribution
Associated with plasma proteins (albumin) by 95%. Cumulation is not observed.
Metabolism
Almost completely metabolized in the liver to form inactive metabolites.
Removal
T1/2 is 2-5 hours. 60-80% of Nifedipine in the form of metabolites is excreted in the urine, the rest with feces. Less than 0.1% of the active substance is found unchanged in the urine.
Pharmacokinetics in special clinical situations
When abnormal liver function increases T1/2 and a decrease in total plasma clearance.
Indications and usage
- stable angina (angina pectoris);
- angiospastic stenocardia (Prinzmetal stenocardia, variant angina pectoris);
- Essential arterial hypertension.
Install individually.
The average dose is 20 mg 2 times / day. With insufficient severity of the clinical effect, a gradual increase in the dose of Corinfar retard to 40 mg 2 times / day is possible.
The maximum daily dose of 80 mg.
The interval between doses should not be less than 4 hours. When prescribing the drug 2 times / day, the recommended interval in reception is approximately 12 hours (in the morning and in the evening).
Tablets are taken after a meal, without chewing and drinking plenty of fluids.
Adverse reactions
Cardiovascular: at the beginning of treatment - flushing of the face and skin of the upper body with a sensation of heat, an increase in the frequency, duration and severity of angina pectoris; possible occurrence of a state of stupor, tachycardia, lowering blood pressure, swelling of the legs,; in rare cases - the development of myocardial infarction.
Gastrointestinal: rarely - nausea, epigastric overflow, diarrhea; in rare cases - increased levels of hepatic transaminases, allergic hepatitis, gum hyperplasia.
Urogenital: rarely (soon after taking the drug at the beginning of treatment) - perhaps increased urine excretion; in patients with impaired renal function, there may be a temporary deterioration in renal function.
Allergic reactions: pruritus, urticaria, rash; in rare cases, the occurrence of exfoliative dermatitis.
Nervous system: at the beginning of treatment, often - transient headaches; sometimes - a state of stupor, dizziness, fatigue, paresthesia; in rare cases - the occurrence of tremor, lung disorders of vision (especially when using the drug in high doses).
Hemic and lymphatic: anemia, leukopenia, thrombocytopenia (sometimes with manifestations of purpura).
Other: transient increase in plasma glucose levels; in some cases - myalgia (especially when using the drug in high doses). Single cases of gynecomastia are described (in elderly patients, especially with long-term use of the drug).
Contraindications
- cardiogenic shock;
- pronounced stenosis of the mouth of the aorta;
- unstable angina;
- acute period of myocardial infarction (during the first 4 weeks);
- pregnancy;
- lactation period (breastfeeding);
- Hypersensitivity to nifedipine.
Pregnancy and breastfeeding
Corinfar retard is contraindicated for use in pregnancy.
Nifedipine is excreted in breast milk. Data on the effect of nifedipine on an infant is not enough. Therefore, if necessary, the use of Corinfar retard during lactation, breastfeeding should be stopped.
Cautions
Care should be taken when prescribing Corinfar Retard to patients with severe hypotension (systolic blood pressure less than 90 mm Hg), chronic heart failure in the decompensation phase, as well as elderly patients over the age of 60 and patients with severe arterial hypertension and irreversible renal failure and hypovolemia on hemodialysis (due to the high risk of a sharp drop in blood pressure).
Corinfar retard is prescribed to patients with impaired liver function only with careful medical supervision, and dose adjustment should be carried out if necessary.
Cancel Corinfar retard should be gradually, because with a sudden cessation of the drug (especially after long-term treatment) may develop withdrawal syndrome, manifested in a sharp increase in blood pressure or myocardial ischemia.
When drinking alcohol during therapy with Corinfar retard, a slowing down of the speed of psychomotor reactions associated with a decrease in blood pressure is possible.
Use in pediatrics
Clinical experience with the drug in children is insufficient.
Influence on ability to drive motor transport and control mechanisms
When taking Corinfar retard, especially at the beginning of treatment and when changing the drug, it is possible to slow down the speed of psychomotor reactions associated with a decrease in blood pressure. This should be taken into account by persons engaged in potentially hazardous activities that require increased attention and speed of psychomotor reactions.
Overdosage
Symptoms: loss of consciousness up to the development of coma, a fall in blood pressure, tachycardia or bradycardia, hyperglycemia, metabolic acidosis, hypoxia.
Treatment: artificial vomiting, gastric lavage, symptomatic therapy aimed at maintaining the activity of the cardiovascular system.
Drug Interactions
With simultaneous use of Corinfar retard with other antihypertensive drugs, as well as with tricyclic antidepressants, there is an increase in the hypotensive effect of Corinfar retard.
With simultaneous use of Corinfar retard with nitrates, the effect of Corinfar retard on blood pressure and heart rate is enhanced.
With simultaneous use of Corinfar retard with beta-blockers, a more dramatic drop in blood pressure may occur, in addition, there have been cases of weakened cardiac activity.
With the simultaneous use of Corinfar retard and cimetidine (to a lesser extent ranitidine), the effects of Corinfar retard may be enhanced.
With simultaneous use of Corinfar with quinidine, in some cases there was a decrease in the concentration of quinidine in the blood plasma, and after the withdrawal of Corinfar retard, a sharp increase in the concentration of quinidine in the plasma.
With simultaneous use of Corinfar with Digoxin and theophylline, in some cases, changes in the plasma concentration of the latter were noted.
Storage conditions
The drug should be stored in a dark place. Shelf life - 3 years.
The drug is released by prescription.
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