Pharmacodynamics. Ascorbic acid (vitamin C) is a water-soluble vitamin that promotes optimal tissue metabolism. takes an active part in redox reactions, forming with dehydroascorbic acid a hydrogen proton transfer system, has antioxidant properties, due to which it ensures the stability of cell membranes. participates in the synthesis of the main substance of the connective tissue of the vascular wall, thus preventing the development of hemorrhagic diathesis. is not synthesized in the human body. with insufficient intake of ascorbic acid with food, bleeding from the gums and mucous membranes develops. participates in the exchange of glucose, catabolism of Hs, synthesis of steroid hormones. during stress reactions, the content of ascorbic acid in the body and tissues of the adrenal glands, in particular, significantly decreases, which confirms the participation of ascorbic acid in adaptation reactions. is able to provide an anti-anemic effect due to the effect on iron metabolism. reduces trivalent iron to divalent iron, which is transported with the bloodstream.
Pharmacokinetics. After parenteral administration, ascorbic acid easily penetrates into leukocytes, platelets, and then into all tissues. It accumulates mainly in organs with an increased level of metabolic processes, in particular in the tissues of the adrenal glands. It is found in tissues both in a free state and in the form of compounds. It is excreted from the body with urine both unchanged and in the form of metabolites.
Alcohol consumption and smoking accelerate the destruction of ascorbic acid (transformation into inactive metabolites), sharply reducing its reserves in the body.
Hypovitaminosis c; scurvy; bleeding (uterine, pulmonary, nasal, hepatic); hemorrhagic diatheses; bleeding as a syndrome of radiation sickness; various intoxications and infectious diseases; nephropathy of pregnant women; Addisonian crisis; overdose of anticoagulants; bone fractures and slowly granulating wounds; various dystrophies; increased nervous tension and hard physical work.
The preparation is prescribed intravenously as a jet or drip and intravenously.
Intravenously inject for 1-3 minutes. For intravenous drip administration, a single dose of the preparation is dissolved in 50-100 ml of 0.9% sodium chloride solution and administered by slow intravenous infusion at a rate of 30-40 drops per minute.
Intramuscular injection deep into the muscle.
Doses are set individually, taking into account the nature and severity of the disease.
Adults and children over 12 years old. The preparation is prescribed in a dose of 50-150 mg (0.5-1.5 ml of a 10% solution or 1-3 ml of a 5% solution) per day. The maximum single dose is 200 mg (2 ml of 10% solution), daily - 1 g (10 ml of 10% solution). In acute poisoning, the maximum dose is up to 500 mg (50 ml of 10% solution) per day.
For children under 12 years of age. The preparation is prescribed intravenously in a daily dose of 5-7 mg/kg of body weight in the form of a 5% solution (0.5-2 ml). Usually, daily doses for children are: under the age of 6 months - 30 mg, 6-12 months - 35 mg, 1-3 years - 40 mg, 4-10 years - 45 mg, 11-12 years - 50 mg.
The maximum daily dose is 100 mg.
Special groups of patients. For patients with recurrent kidney stone formation, the daily dose of ascorbic acid should not exceed 100-200 mg.
For patients with severe or end-stage renal failure (dialysis patients), the daily dose of ascorbic acid should not exceed 50-100 mg.
For patients with glucose-6-phosphate dehydrogenase deficiency, the daily dose of ascorbic acid should not exceed 100-500 mg.
Hypersensitivity to the active substance or to other components of the medicinal product; diabetes; increased blood coagulation; tendency to thrombosis; thrombophlebitis; urolithiasis (including hyperoxaluria); kidney failure; progressive malignant diseases; hemochromatosis; thalassemia; polycythemia; leukemia; sideroblastic anemia; sickle cell anemia; deficiency of glucose-6-phosphate dehydrogenase.
From the gastrointestinal tract: nausea, diarrhea, stomach cramps.
On the part of the kidneys and urinary tract: hyperoxalaturia, with long-term use in high doses - damage to the glomerular apparatus of the kidneys, formation of kidney stones from calcium oxalate.
From the side of metabolism, metabolism: hypervitaminosis C, with long-term use in high doses - inhibition of the function of the insular apparatus of the pancreas (hyperglycemia, glucosuria) and glycogen synthesis, sodium and fluid retention, impaired zinc and copper metabolism.
From the side of the nervous system: headache, dizziness, fatigue, with long-term use in high doses - sleep disturbance, increased excitability of the central nervous system.
From the side of the cardiovascular system: a decrease in the permeability of capillaries, deterioration of tissue trophism, with long-term use in high doses - myocardial dystrophy, increased blood pressure, development of microangiopathy.
From the side of the blood and lymphatic system: with long-term use in high doses - thrombocytosis, hyperprothrombinemia, thrombus formation, erythrocytopenia, neutrophilic leukocytosis, in patients with a deficiency of glucose-6-phosphate dehydrogenase, it can cause hemolysis of erythrocytes.
From the immune system: hypersensitivity reactions, including rash, skin hyperemia, itching, urticaria, anaphylactic shock.
General disorders and reactions at the injection site: hyperthermic syndrome, with IV administration, a burning sensation, changes at the injection site are possible.
Pregnancy: with intravenous administration in high doses - the threat of termination of pregnancy.
Ascorbic acid as a reducing agent can distort the results of various laboratory tests, in particular cause a false positive result in the test for the presence of glucose in the urine and a negative result in the test for the presence of hidden blood in the feces, as well as underestimation of the results in studies of the concentration of LDH and aminotransferases in the blood plasma.
Due to the stimulating effect of ascorbic acid on the synthesis of corticosteroid hormones, it is necessary to monitor the function of the adrenal glands and blood pressure.
With long-term use in high doses, suppression of the function of the insular apparatus of the pancreas is possible, therefore, during long-term treatment, it is necessary to regularly monitor the function of the pancreas.
Therapy in high doses cannot be carried out in patients with a tendency to recurrent urolithiasis. To reduce the risk of crystalluria, patients with renal insufficiency should ensure adequate fluid intake (1.5-2 l/day).
In patients with increased iron content in the body, ascorbic acid should be used in minimal doses.
High doses of the preparation should not be prescribed to patients on a low-sodium diet.
The appointment of ascorbic acid to patients with fast-proliferating and intensively metastasizing tumors can worsen the course of the disease. For patients undergoing chemotherapy, the preparation should be prescribed no earlier than 1-3 days (depending on the T ½ of the anticancer preparation) after chemotherapy, as there is no clinical data on a possible interaction.
Use during pregnancy and breastfeeding. The minimum daily need for ascorbic acid in the II-III trimester of pregnancy is about 60 mg. Ascorbic acid penetrates the placental barrier. It should be borne in mind that the fetus can adapt to high doses of ascorbic acid taken by a pregnant woman, and then the newborn may develop ascorbic acid as a withdrawal reaction. Therefore, during pregnancy, the preparation should not be prescribed in increased doses, except in cases where the potential benefit to the mother exceeds the possible risk to the fetus.
The minimum daily need for ascorbic acid during breastfeeding is 80 mg. A mother's diet containing an adequate amount of ascorbic acid is sufficient to prevent deficiency in an infant. Ascorbic acid penetrates into breast milk. Theoretically, there is danger for the child when the mother uses high doses of ascorbic acid (during breastfeeding, it is not recommended to exceed the daily need for ascorbic acid). If it is necessary to prescribe increased doses of the preparation, breastfeeding should be stopped.
Children. The preparation is used in pediatric practice.
The ability to influence the speed of reactions when driving vehicles or working with other mechanisms. Does not affect in recommended doses.
- With benzylpenicillin, tetracycline, salicylates - an increase in the concentration of preparations in the blood;
- with ethinyl estradiol (ascorbic acid - in a dose of 1 g/day) - an increase in the concentration of ethinyl estradiol (including oral contraceptives) in the blood;
- with oral contraceptives - a decrease in the concentration of preparations in the blood;
- with tetracycline and acetylsalicylic acid - increased excretion of ascorbic acid with urine;
- high doses of ascorbic acid can lower the pH of urine, resulting in decreased tubular reabsorption of amphetamine and tricyclic antidepressants used simultaneously;
- with deferoxamine - increased removal of iron;
- with heparin, indirect anticoagulants, antipsychotic preparations, phenothiazine derivatives - decrease in the effectiveness of preparations;
- with isoprenaline - reduction of the chronotropic effect of the preparation;
- with short-acting sulfonamides - increased development of crystalluria;
- with preparations that have an acidic reaction - slowing down the excretion of preparations by the kidneys;
- with preparations that have an alkaline reaction, mexiletine, amphetamine, tricyclic antidepressants - acceleration of the release of preparations by the kidneys;
- with acetylsalicylic acid - increased urinary excretion of ascorbic acid and decreased excretion of acetylsalicylic acid;
- with barbiturates, primidone - increased excretion of ascorbic acid with urine;
- with preparations of the quinoline series, calcium chloride, salicylates, GCS - with long-term use - depletion of ascorbin reserves with long-term use or use in high doses, disulfiram-ethanol interaction is possible.
Ascorbic acid increases the concentration of salicylates in the blood (increases the risk of crystalluria).
Participates in the metabolism of phenylalanine, tyrosine, folic acid, norepinephrine, histamine.
The simultaneous use of ascorbic acid and deferoxamine increases the tissue toxicity of iron, especially in the heart muscle, which can lead to decompensation of the circulatory system.
Incompatibility. Ascorbic acid has a high oxidation-reduction potential, so it can change the chemical composition of other medicines. When considering the possibility of simultaneous use with other medicinal products, it is necessary to ensure their compatibility.
Acute poisoning with ascorbic acid has not been described. high doses of ascorbic acid can cause gastrointestinal disturbances, including diarrhea, and lead to hyperoxaluria and the formation of oxalate stones. doses of 600 mg/day have a diuretic effect. with intravenous administration in high doses, there may be a threat of termination of pregnancy. with a single use of excessive doses of the preparation, nausea, vomiting, bloating, abdominal pain, itching, skin rashes, and increased excitability may occur.
Treatment: discontinuation of the preparation, symptomatic therapy.
In the original packaging at a temperature not higher than 25 °C. Do not freeze.