Amoxicillin 500 mg
An antibiotic of a group of semisynthetic penicillins with a wide spectrum of action. It is a 4-hydroxyl analogue of ampicillin. It has a bactericidal effect. Active against aerobic gram-positive bacteria: Staphylococcus spp. (with the exception of strains producing penicillinase), Streptococcus spp .; aerobic gram-negative bacteria: Neisseria gonorrhoeae, Neisseria meningitidis, Escherichia coli, Shigella spp., Salmonella spp., Klebsiella spp. To amoxicillin resistant microorganisms that produce penicillinase. In combination with metronidazole, it is active against Helicobacter pylori. Amoxicillin is believed to inhibit the development of metronidazole resistance by Helicobacter pylori. There is cross-resistance between amoxicillin and ampicillin. The spectrum of antibacterial action expands with the simultaneous use of amoxicillin and a beta-lactamase inhibitor clavulanic acid. This combination increases the activity of amoxicillin against Bacteroides spp., Legionella spp., Nocardia spp., Pseudomonas (Burkholderia) pseudomallei. However, Pseudomonas aeruginosa, Serratia marcescens, and many other gram-negative bacteria remain resistant.
When administered amoxicillin is rapidly and completely absorbed from the gastrointestinal tract, is not destroyed in the acidic environment of the stomach. Cmax of amoxicillin in the blood plasma is reached in 1-2 hours. With a dose increase of 2 times, the concentration also increases by 2 times. In the presence of food in the stomach does not reduce the total absorption. With the / in, in / m the introduction and ingestion in the blood achieved similar concentrations of amoxicillin. The binding of amoxicillin to plasma proteins is about 20%. Widely distributed in tissues and body fluids. High concentrations of amoxicillin in the liver are reported. T1 / 2 of plasma is 1-1.5 hours. About 60% of the dose taken orally is excreted unchanged in the urine by glomerular filtration and tubular secretion; at a dose of 250 mg, the concentration of amoxicillin in the urine is more than 300 μg / ml. Some amount of amoxicillin is determined in the feces. In newborns and the elderly, T1 / 2 may be longer. In renal failure, T1 / 2 can be 7–20 hours. In small quantities, amoxicillin penetrates the BBB during inflammation of the pia mater. Amoxicillin is removed by hemodialysis.
For use as monotherapy and in combination with clavulanic acid: infectious and inflammatory diseases caused by susceptible microorganisms, incl. bronchitis, pneumonia, angina, pyelonephritis, urethritis, gastrointestinal infections, gynecological infections, infections of the skin and soft tissues, listeriosis, leptospirosis, gonorrhea. For use in combination with metronidazole: chronic gastritis in the acute phase, peptic ulcer and duodenal ulcer in the acute phase associated with Helicobacter pylori.
Infectious mononucleosis, lymphocytic leukemia, severe gastrointestinal infections with diarrhea or vomiting, respiratory viral infections, allergic diathesis, bronchial asthma, hay fever, and hypersensitivity to penicillins and / or cephalosporins. For use in combination with metronidazole: diseases of the nervous system; blood disorders, lymphocytic leukemia, infectious mononucleosis; Hypersensitivity to nitroimidazole derivatives. For use in combination with clavulanic acid: a history of abnormal liver function and jaundice associated with taking amoxicillin in combination with clavulanic acid.
Use during pregnancy and lactation
Amoxicillin penetrates the placental barrier, in small quantities excreted in breast milk. If you need to use amoxicillin during pregnancy, you should carefully weigh the expected benefits of therapy for the mother and the potential risk to the fetus. To use amoxicillin with caution during lactation (breastfeeding).
Dosage and administration
Individual. For oral administration, a single dose for adults and children over 10 years old (weighing more than 40 kg) is 250-500 mg, for severe cases of the disease - up to 1 g. For children aged 5-10 years, a single dose is 250 mg; between the ages of 2 and 5 years old - 125 mg; for children under 2 years of age, the daily dose is 20 mg / kg. For adults and children, the interval between doses is 8 hours. When treating acute uncomplicated gonorrhea, 3 g once (in combination with probenecid). In patients with impaired renal function with a CC of 10–40 ml / min, the interval between doses should be increased to 12 hours; when QA is less than 10 ml / min, the interval between doses should be 24 hours.For parenteral use in adults w / m - 1 g 2 times / day, in / in (with normal kidney function) - 2-12 g / day. Children i / m - 50 mg / kg / day, single dose - 500 mg, the frequency of administration - 2 times / day; in / in - 100-200 mg / kg / day. Patients with impaired renal function, the dose and the interval between injections must be adjusted in accordance with the values of QC.
Allergic reactions: urticaria, erythema, angioedema, rhinitis, conjunctivitis; rarely fever, joint pain, eosinophilia; in rare cases - anaphylactic shock. Effects associated with chemotherapeutic action: possible development of superinfection (especially in patients with chronic diseases or low body resistance). With prolonged use in high doses: dizziness, ataxia, confusion, depression, peripheral neuropathy, convulsions. Mainly when used in combination with metronidazole: nausea, vomiting, anorexia, diarrhea, constipation, epigastric pain, glossitis, stomatitis; rarely - hepatitis, pseudomembranous colitis, allergic reactions (urticaria, angioedema), interstitial nephritis, disorders of hemopoiesis. Mostly when used in combination with clavulanic acid: cholestatic jaundice, hepatitis; rarely, erythema multiforme, toxic epidermal necrolysis, exfoliative dermatitis.
Interaction with other drugs
Amoxicillin may reduce the effectiveness of oral contraceptives. With simultaneous use of amoxicillin with bactericidal antibiotics (including aminoglycosides, cephalosporins, cycloserine, vancomycin, rifampicin), synergism is manifested; with bacteriostatic antibiotics (including macrolides, chloramphenicol, linkosamides, tetracyclines, sulfonamides) - antagonism. Amoxicillin enhances the effect of indirect anticoagulants by suppressing the intestinal microflora, reduces the synthesis of vitamin K and the prothrombin index. Amoxicillin reduces the effect of drugs, in the process of metabolism of which PABK is formed. Probenecid, diuretics, allopurinol, phenylbutazone, NSAIDs reduce tubular secretion of amoxicillin, which may be accompanied by an increase in its concentration in blood plasma.Antacids, glucosamine, laxatives, aminoglycosides slow down and decrease, and ascorbic acid increases the absorption of amoxicillin. With the combined use of amoxicillin and clavulanic acid, the pharmacokinetics of both components does not change.
With caution used in patients prone to allergic reactions. Amoxicillin in combination with metronidazole is not recommended for use in patients younger than 18 years; should not be used for liver disease. Against the background of combination therapy with metronidazole, alcohol is not recommended.