Amoxicillin, tablets 500 mg 20 pcs

Amoxicillin is an antibacterial bactericidal acid-resistant broad-spectrum agent of the group of semisynthetic penicillins. It inhibits transpeptidase, disrupts synthesis of peptidoglycan (support protein of cell wall) during division and growth, causes lysis of bacteria. Due to the wide range of action, the drug is active against both Gram-positive and Gram-negative microorganisms. Clinically relevant gram-negative microorganisms sensitive to amoxicillin include Escherichia coli, Proteus mirabilis, Salmonella, Shigella, Campilobacter, Haemophilus influenzae, Bordetella pertussis, Leptospira, Chlamydia.

In addition, amoxicillin is active against all microorganisms sensitive to penicillin G, such as Streptococcus group A,B,C,G,H,I,M, Streptococcus pneumoniae, Staphylococcus and Neisseria spp, not producing penicillinase, Erysipelothrix rhysiopathiae, Corynebacterium, Bacillus anthracis, Actinomycetes, Streptobacilli, Spirillium minus, Pastereulla multocida, Listeria, Spirochaeta (Leptospira, Treponema, Borrelia) and others, as well as various anaerobic microorganisms (including peptococci, peptostreptococci, clostridia and fusobacteria).

Pharmacokinetics

Absorption – fast, high (93%), food intake has no effect on absorption, is not destroyed in the acidic environment of the stomach. When taken orally in doses of 125 and 250 mg, the maximum concentration is 1.5-3 mcg/ml and 3.5-5 mcg/ml, respectively. The action develops 15-30 min after administration and lasts for 8 h. Time to reach maximum concentration after oral administration is 1-2 hours. It has a large volume of distribution – high concentrations are found in plasma, sputum, bronchial secretion (poor distribution in purulent bronchial secretion), pleural and peritoneal fluid, urine, contents of skin blisters, lung tissue, intestinal mucosa, female genitalia, prostate gland, middle ear fluid, bone, fatty tissue, gall bladder (with normal liver function), fetal tissues.

If the dose is increased by a factor of 2, the concentration also increases by a factor of 2. The concentration in bile exceeds the concentration in plasma by 2-4 times. In amniotic fluid and umbilical cord vessels, the concentration of amoxicillin is 25-30% of the level in plasma of a pregnant woman. It penetrates poorly through the blood-brain barrier; during inflammation of the meninges (meningitis) the concentration in the cerebrospinal fluid is about 20%. Binding with plasma proteins is 17%.

Partially metabolized to form inactive metabolites. Elimination half-life is 1-1.5 hours.

It is eliminated 50-70% unchanged by kidneys through tubular (80%) and glomerular filtration (20%), and 10-20% by liver. A small amount is excreted with breast milk. In patients with impaired renal function (creatinine clearance less than or equal to 15 ml/min), half-life is increased up to 8.5 hours. Amoxicillin is eliminated with hemodialysis.

Indications

Amoxicillin is indicated for infections and inflammatory diseases caused by bacteria not resistant to the drug:

Active ingredient

Composition

1 tablet contains:

the active ingredient:

amoxicillin trihydrate (in terms of amoxicillin) – 500 mg.

How to take, the dosage

Overly, before or after meals.

Adults and children over 10 years of age (with body weight over 40 kg) are prescribed 0.5 g 3 times a day; in severe course of infection 0.75-1 g 3 times a day.

In acute uncomplicated gonorrhea 3 g is prescribed once; when treating women the repeated use of the indicated dose is recommended.

In acute infectious diseases of the gastrointestinal tract (paratyphoid, typhoid) and biliary tract, in gynecological infectious diseases in adults 1.5-2 g 3 times a day or 1-1.5 g 4 times a day.

In case of severe infections (meningitis, septicemia) in adults – up to 6 g a day in 3-4 doses. For children – 250-500 mg 3 times a day. Treatment duration depends on indications and clinical picture and makes usually 5-7 days. In otitis media and similar infections in children two-times use of Amoxicillin is sufficient. In cases of chronic diseases, recurrent infections, infections of severe course, adults are prescribed 750 mg – 1 g 3 times a day, children up to 60 mg/kg per day divided into 3 doses.

In leptospirosis adults – 0.5-0.75 g 4 times a day for 6-12 days.

In listeriosis in adults – 0.5 g 3 times a day for 6-12 days.

In case of salmonella carriage in adults – 1.5-2 g 3 times a day for 2-4 weeks.

In prophylaxis of endocarditis during minor surgical interventions in adults – 3-4 g 1 hour before the procedure. If necessary a second dose is administered after 8-9 hours.

In children the dose is reduced by half.

In patients with impaired renal function and creatinine clearance 15-40 ml/min, the interval between doses is increased up to 12 hours; in creatinine clearance below 10 ml/min the dose is reduced by 15-50%; in anuria the maximum dose is 2 g/day.

Interaction

There may be an increase in the absorption time of digoxin during Amoxicillin therapy.

Probenecid reduces excretion of amoxicillin by the kidneys and increases the concentration of amoxicillin in bile and blood.

The concomitant use of amoxicillin and other bacteriostatic agents (macrolides, tetracyclines, sulfonamides, chloramphenicols) should be avoided because of the possibility of antagonism. When concomitant use of aminoglycosides and amoxicillin a synergistic effect may develop.

The concomitant use of amoxicillin and disulfiram is not recommended.

The concomitant use of methotrexate and amoxicillin may increase the toxicity of the former, probably due to competitive inhibition of renal tubular secretion of methotrexate by amoxicillin.

Antacids, glucosamine, laxative drugs, food, aminoglycosides slow down and decrease absorption, ascorbic acid increases absorption of amoxicillin.

Increases the effectiveness of indirect anticoagulants (by suppressing intestinal microflora, reduces the synthesis of vitamin K and prothrombin index); reduces the effectiveness of estrogen-containing oral contraceptives; drugs that metabolize paraaminobenzoic acid (PABA), ethinylestradiol preparations – risk of bleeding “breakthrough”.

Diuretics, allopurinol, oxyphenbutazone, phenylbutazone, nonsteroidal anti-inflammatory drugs and other drugs that block tubular secretion increase the blood concentration of amoxicillin.

Allopurinol increases the risk of developing a skin rash.

Special Instructions

In case of course treatment it is necessary to monitor the hematopoietic, hepatic and renal function. Superinfection due to growth of microflora insensitive to it is possible, which requires appropriate changes in antibiotic therapy.

When administered to patients with bacteremia a bacteriolysis reaction may develop (Jarisch-Herxheimer reaction).

In patients with hypersensitivity to penicillins cross-allergic reactions with cephalosporin antibiotics are possible.

In the treatment of mild diarrhea, anti-diarrheal drugs that reduce intestinal peristalsis should be avoided; kaolin- or attapulgit-containing anti-diarrheal agents may be used. If the diarrhea is severe, a physician should be consulted.

The treatment must be continued for an additional 48-72 hours after clinical signs of illness have disappeared.

In case of concomitant use of estrogen-containing oral contraceptives and amoxicillin other or additional contraceptive methods should be used, if possible.

Contraindications

The drug should be used with caution in patients with impaired renal function; severe digestive disorders accompanied by persistent vomiting and diarrhea; allergic diathesis asthma; pollinosis; with viral infections; with acute lymphoblastic leukemia; with infectious mononucleosis (due to increased risk of erythematous skin rash); in children over 3 years old.

Side effects

The frequency of side effects is stated according to the following gradation: very frequent – more than 10%; frequent – from 1 to 10%; infrequent – from 0.1 to 1%; rare – from 0.01 to 0.1%; very rare – less than 0.01%.

Systemic diseases: frequent – tachycardia, phlebitis; rare – decrease of BP; very rare – prolongation of QT interval.

The blood and lymphatic system: frequent – eosinophilia, leukopenia; rare – neutropenia, thrombocytopenia, agranulocytosis; very rare – anemia (including hemolytic), thrombocytopenic purpura, pancytopenia.

Nervous system disorders: frequent – somnolence, headache, dizziness; rare – nervousness, agitation, anxiety, ataxia, change of behavior, peripheral neuropathy, anxiety, sleep disturbance, depression, paresthesia, tremor, confusion, convulsions; very rare – hypersthesia, visual, olfactory and tactile sensitivity disorders, hallucinations.

Urogenital system disorders: rare – interstitial nephritis, increased serum creatinine concentration.

Gastrointestinal and liver disorders: dysbacteriosis, change in taste, stomatitis, glossitis; frequent – nausea, diarrhea, increased liver parameters (ALT, AST, alkaline phosphotase, γ-glutamyltransferase), increased serum bilirubin concentration; rare – vomiting, dyspepsia, pain in epigastrium, hepatitis, cholestatic jaundice; very rare – acute liver failure, diarrhea with blood admixture, pseudomembranous colitis, appearance of black color of tongue.

Muscular system disorders: rare – arthralgia, myalgia, tendon diseases including tendinitis; very rare – tendon rupture (possible bilateral and 48 hours after treatment start), muscle weakness, rhabdomyolysis.

Skin disorders: frequent – pruritis, rash; rare – urticaria; very rare – photosensitization, swelling of the skin and mucous membranes, erythema malignant exudative (Stevens-Johnson syndrome), toxic epidermal necrolysis (Lyell’s syndrome).

Endocrine system disorders: rare – anorexia; very rare – hypoglycemia, especially in patients with diabetes.

Respiratory system: rare – bronchospasm, dyspnea; very rare – allergic pneumonitis.

General: rare – general weakness; very rare – increase in body temperature.

Others: difficulty breathing, vaginal candidiasis; rare – superinfection (especially in patients with chronic disease or reduced body resistance), serum-like reactions; single cases – anaphylactic shock.

Overdose

Symptoms: nausea, vomiting, diarrhea, water-electrolyte imbalance (as a consequence of vomiting and diarrhea).

Treatment: gastric lavage, activated charcoal, saline laxatives, drugs to maintain water-electrolyte balance; hemodialysis.

Similarities