Dexamethasone

General characteristics. Structure:

Active ingredient: 4 mg of dexamethasone of sodium phosphate (in terms of dexamethasone phosphate) in 1 ml.

Pharmacological properties:

Pharmacodynamics. Interacts with specific cytoplasmatic receptors and forms the complex getting into a kernel of a cell and stimulating synthesis of MRNK: the last induces formation of proteins, including the lipokortin mediating cellular effects. Lipokortin oppresses A2 phospholipase, suppresses a liberation of arachidonic acid and inhibits biosynthesis of endoperoxides, PG, the leukotrienes promoting processes of an inflammation, an allergy, etc. Interferes with release of mediators of an inflammation from eosinophils and mast cells.

Brakes activity of hyaluronidase, a collagenase and proteases, normalizes functions of an intercellular matrix of cartilaginous tissue and a bone tissue. Reduces permeability of capillaries, stabilizes cellular membranes, including lizosomalny, release of cytokines (interleykin and gamma интерферрона) from lymphocytes oppresses and macrophages, causes involution of an adenoid tissue. Recovers sensitivity of adrenoceptors to catecholamines.

Accelerates a catabolism of proteins, reduces glucose utilization by peripheral fabrics and raises a gluconeogenesis in a liver. Reduces absorption and increases calcium removal; sodium (and water) secretion of AKTG detains.

Pharmacokinetics. At in introduction contacts specific protein carrier – transcortinum – for 70-80%; at introduction of high doses of drug linkng with proteins decreases to 60-70% due to saturation of transcortinum. Easily passes through gistogematichesky barriers, including hematoencephalic and placental.

At inside it is quickly and completely soaked up generally in proximal department of a small bowel; absorption in distal department makes about a half from that in proximal. Smakh is reached within 1-2 hours. It Biotransformirutsya in a liver, generally by conjugation with glucuronic and sulfuric acids, to inactive metabolites.

The elimination half-life makes of T1/2 blood 3-5 hours, a biological elimination half-life – 36-54 hours. At parenteral administration it is metabolized quicker and respectively pharmacological effects are less long. It is removed generally with urine (a small part – the lactating glands) in the form of 17 ketosteroids, glyukuroid, sulfates. In an invariable look about 15% of dexamethasone are allocated with urine. When drawing absorption is defined on skin by many factors (integrity of an integument, existence of an occlusive bandage, a dosage form, etc.) and strongly varies.

Indications to use:

Addison's disease, inborn hypoplasia of adrenal glands, adrenal insufficiency (usually in combination with mineralokortikoida), an adrenogenital syndrome, a thyroiditis (acute, subacute), a hypothyroidism, a tumoral hypercalcemia, shock (anaphylactic, posttraumatic, postoperative, cardiogenic, hemotransfusionic, etc.), a pseudorheumatism in an aggravation phase, an acute rheumatic carditis, collagenoses (rheumatic diseases, the disseminated lupus erythematosus, etc.), inflammatory and degenerative diseases of joints (arthritises, a tendovaginitis, a bursitis, an epicondylitis, a styloiditis, osteochondrosis, an osteoarthrosis, Bekhterev's disease, etc.), a miositis, infectious and allergic bronchial asthma, the asthmatic status, anaphylactoid reactions, including caused by medicines; brain hypostasis (at tumors, a craniocereberal injury, neurosurgical intervention, a hematencephalon, encephalitis, meningitis, radiation injury of lungs); nonspecific ulcer colitis, hepatitis, a sarcoidosis, a berylliosis, the disseminated tuberculosis (only in combination with antituberculous remedies), Leffler's disease, etc. a serious respiratory illness; anemias (autoimmune, hemolitic, inborn, hypoplastic, idiopathic, an eritroblastopeniya), an idiopathic Werlhof's disease (at adults), secondary thrombocytopenia, a lymphoma (hodzhkinsky and nekhodzhkinsky), leukemia, a lymphoid leukosis (acute, chronic), an agranulocytosis, a plasmacytoma, etc. blood diseases; nephrotic syndrome; serious infectious diseases (at an obligatory combination to antibiotics), heavy inflammatory processes after injuries of an eye and operations.

Route of administration and doses:

It is intended for intravenous, intramuscular, intra joint, periartikulyarny and retrobulbar administration.

The adult at acute and medical emergencies enter in/in slowly, struyno or kapelno, or in oil 3-4 once in a dose of 4-20 mg a day. Maximum single dose of-80 mg. A maintenance dose – 0,2-9 mg a day. A course of treatment 3-4 days, then pass to oral administration of dexamethasone. To children – in oil each 12-24 hours in a dose of 0,02776-0,16665 mg/kg.

Vnutrisustavno or periartikulyarno (in soft tissues) to adults and teenagers enter (into the defeat center) in a dose 0,2-6 mg (2-8 mg), repeatedly with an interval from 3 days to 3 weeks as required; the maximum dose for adults – 80 mg a day.

At shock, the adult, – in/in 20 mg once, then on on 3 mg/kg during 24 h in the form of continuous infusion or in/in once 2-6 mg/kg, or in/in on 40 mg each 2-6 hours.

At wet brain (adult) – 10 mg in/in, then on 4 mg each 6 hours in oil before elimination of symptoms; the dose is reduced in 2-4 days and gradually – within 5-7 days – stop treatment.

At insufficiency of bark of adrenal glands (children) in oil on 0,0233 mg/kg (0,67/mg2) in days in 3 injections every third day, or daily on 0,00776-0,01165 mg/kg (0,233-0,335 mg/sq.m) a day.

Features of use:

It is limited to use at: round ulcers of a GIT, a peptic ulcer of a stomach and duodenum, esophagites, gastritises, an intestinal anastomosis (in the next anamnesis); congestive heart failure, arterial hypertension, fibrinferments, diabetesen mellitus, osteoporosis, Itsenko-Cushing's disease, acute renal and/or liver failure, psychoses, convulsive states, myasthenias, open angle glaucoma, AIDS, беременност, feeding by a breast.

Use during pregnancy and a lactation. Use during pregnancy is allowed if the expected effect of therapy exceeds potential risk for a fruit. For the period of treatment it is necessary to stop breastfeeding.

Side effects:

Delay of sodium and water, loss of potassium and calcium, hypostases, GIT erosive cankers (with an aggravation of a peptic ulcer up to perforation, bleeding), hemorrhagic pancreatitis, a GIT atony, increase in appetite, nausea and vomiting, a hepatomegalia, muscular weakness, a myopathy, osteoporosis, pathological changes, ruptures of sinews, arrhythmia, bradycardia, increase in the ABP, congestive heart failure, a heart attack and dystrophy of a myocardium, an Icenco-Cushing syndrome, a hyperglycemia, a giperlipoproteinemiya, negative nitrogenous balance, a dysmenorrhea, a growth inhibition at children, a hirsutism, decrease in immunity, suppression of regenerative and reparative processes, dizziness, headaches, disturbances of mood, psychoses, increase in intracranial pressure, a spasm, thinning and vulnerability of skin, a petechia, ecchymomas, striya, an erythema and change of a xanthopathy, the increased sweating, increase in intraocular pressure, an exophthalmos; fibrinferments and thromboembolisms, withdrawal (indisposition, pains: head, abdominal, joint and muscular); depression, secondary adrenal insufficiency; seldom – allergic reactions (rash, an itch).

Interaction with other medicines:

Therapeutic and toxic effects of dexamethasone reduce barbiturates, Phenytoinum, rifampicin (accelerate metabolism); Somatotropinum; antacids (reduce absorption), strengthen – estrogensoderzhashchy oral contraceptives.

The risk of arrhythmias and hypopotassemia raise cardiac glycosides and diuretics, probability of hypostases and arterial hypertension – natriysoderzhashchy drugs and nutritional supplements, a heavy hypopotassemia, heart failure and osteoporosis – Amphotericinum In and karboangidraza inhibitors; risk of erosive cankers and bleedings from a GIT – non-steroidal anti-inflammatory drugs.

At simultaneous use with live antiviral vaccines and against the background of other types of immunization increases risk of activation of viruses and development of an infection.

Weakens hypoglycemic activity of insulin and peroral antidiabetic means; anticoagulating – coumarins; diuretic – diuretic diuretics; immunotropny – vaccination (suppresses antibodyformation).

Worsens portability of cardiac glycosides (causes deficit of potassium), reduces concentration of salicylates and a prazikvantel in blood.

Contraindications:

Hypersensitivity, system mycoses, amoebic infections, infectious damages of joints and circumarticular soft tissues, active forms of tuberculosis, the period before and after preventive inoculations (especially antiviral), glaucoma, an acute purulent eye infection (retrobulbar introduction).

Overdose:

Messages on acute toxic poisonings and/or lethal outcomes owing to overdose of glucocorticoids are extremely rare. At development of the undesirable phenomena – the symptomatic treatment directed to maintenance of the vital functions; an Icenco-Cushing syndrome – purpose of an aminoglutemid.

Issue conditions:

According to the recipe

Packaging:

Solution for injections of 0,4% in ampoules of 1 ml in a blister strip packaging No. 5х1, No. 5х2; solution for injections of 0,4% in ampoules of 2 ml in a blister strip packaging No. 5х1, No. 5х2.