Calcium ions reduces the current through the “slow” calcium channels into cells, preferably into cardiomyocytes, smooth muscle cells of coronary and peripheral arteries, thus decreasing peripheral vascular resistance and increasing coronary artery supplying the especially large vessels, or even partially intact wall segments stenosed vessels. In addition, nifedipine reduces the tone of smooth muscles of coronary arteries, thus, prevents vasoconstriction, increased blood flow in poststenotic departments sustanon 250 gains vessels and increases oxygen delivery to the myocardium, decreases myocardial oxygen demand by reducing peripheral vascular resistance (afterload) and chronic administration it capable of preventing the development of new atherosclerotic lesions in the coronary arteries.
Nifedipine reduces the tone of smooth muscle of the arterioles, thereby reducing the increased peripheral vascular resistance, and therefore, blood pressure (BP). Early treatment with nifedipine may be temporary reflex increases in heart rate and, consequently, cardiac output. However, this increase is not so much to compensate for the expansion of blood vessels. In addition, nifedipine and for short term use, increases the excretion of sodium and water from the body. Hypotensive effect of nifedipine is especially pronounced in patients suffering from hypertension. Patients with hypertension and the existence, at steps, another risk factor, and decreases the incidence of cardiovascular and cerebrovascular events to the same extent as the combination of diuretics.
Absorption. After oral administration of nifedipine almost completely absorbed from the gastrointestinal tract. The bioavailability of nifedipine with uncontrolled release of 45-56%, due to the effect of “first pass” through the liver. Bioavailability relative to that of nifedipine with uncontrolled release of 68-86%. Ingestion slightly reduces the initial absorption rate, but does not affect the bioavailability. Nifedipine is released from the pill sustanon 250 gains through a special membrane by the osmotic gradient with a constant zero-order rate, thus there is a controlled increase in the concentration of the drug in the blood plasma, which reaches a plateau after about 6-12 hours after taking the pill. Within 24 hours, kept at a constant concentration of drug in blood plasma. Nifedipine release rate is independent of pH and medium-motility of the gastrointestinal tract. When receiving, 30 mg and 60 mg, the maximum concentration (. C max) in plasma is respectively 20-21 ng / ml and 43-55 ng / ml, and the time to reach this concentration – 12-15 hours and 9.7 hours, respectively. Communication with the plasma proteins (albumin) of about 95%.
Metabolism . After oral administration of nifedipine is metabolized in the gut wall and liver to inactive metabolites.
Withdrawal . The half-life (T 1/2) of nifedipine with uncontrolled release of 1.7 -3.4 hours. Concentration plasma is maintained as a plateau throughout the period of release and absorption, release and only after the last dose of the tablet, its concentration in the plasma starts to decline, and T corresponds to that half the uncontrolled release of nifedipine. Nifedipine is excreted as inactive metabolites via the kidneys, only 5-15% of the bile through the intestines. The nifedipine is present unchanged in urine in trace amounts (less than 0.1%). It penetrates the blood-brain and placental barrier, excreted in breast milk.
Hemodialysis and peritoneal dialysis have no effect on the pharmacokinetics of nifedipine, plasmapheresis enhances its elimination.
During the passage through the digestive tract of biologically inactive components of the tablet remain unchanged and excreted in the form of an insoluble shell.
Abnormal liver function. Decreased clearance of nifedipine, if necessary, in severe cases – correction dosing regimen.
Coronary heart disease: stable angina (angina of effort). Arterial hypertension.
- Hypersensitivity sustanon 250 gains to nifedipine
- Pregnancy and lactation
- Cardiogenic shock
- Co-administration with rifampicin
- Severe hypotension (systolic blood pressure below 90 mm Hg)
- The presence of ileostomy after proctocolectomy
- Age 18 years (effectiveness and safety have been established).With care – heart failure, severe aortic stenosis, subaortic stenosis, acute myocardial infarction with left ventricular failure, bradycardia, liver failure, severe violations of cerebral circulation, light and moderate arterial hypotension, stenosis of any gastrointestinal tract, advanced age, patients with malignant hypertension and hypovolaemia, hemodialysis.
Pregnancy and lactation
The use of nifedipine is contraindicated during the pregnancy period as possible embryotoxic, foetotoxic and teratogenic effects of the drug.
Nifedipine passes into breast milk, therefore, if the reception sustanon 250 gains is required, breast-feeding should be discontinued.