Pharmacological properties
Pharmacodynamics. amoxicillin is a broad-spectrum bactericidal antibiotic of the group of semi-synthetic penicillins. inhibits the synthesis of the bacterial cell wall. amoxicillin is inactive against microorganisms that produce beta-lactamases. the level of resistance of susceptible microorganisms can vary depending on the region.
The following types of microorganisms are sensitive to the preparation: gram-positive aerobes: Enterococcus faecalis, Listeria monocytogenes, beta-hemolytic streptococci (groups A, B, C, G) - Streptococcus agalactiae, Streptococcus bovis, Streptococcus pyogenes; gram-negative aerobes: Helicobacter pylori; anaerobes: Peptostreptococci; others: Borrelia.
Inconsistently sensitive (acquired resistance can become a problem): Enterococcus faecium, Streptococcus pneumoniae, Streptococcus viridans, Escherichia coli, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, Proteus mirabilis, Salmonella spp., Prevoppus mirabilis, Salmonella spp., Preppus mirabilis, Salmonella spp., Spp., Spp.
Resistant species are Staphylococcus aureus, Acinetobacter, Citrobacter, Enterobacter, Klebsiella, Legionella, Morganella morganii, Proteus vulgaris, Providencia, Pseudomonas, Serratia, Bacteroides fragilis, Chlamydia, Mycoplasma, Rickettsia.
Pharmacokinetics. Suction. The bioavailability of amoxicillin depends on the dose and is in the range of 75–90%. At doses of 250–1000 mg, bioavailability (AUC and Cmax parameters) is linearly proportional to the dose. At higher doses, the degree of absorption decreases. Food intake has practically no effect on the absorption of the preparation. After taking a single dose of 500 mg, the concentration of amoxicillin in the blood plasma is 6-11 mg / l. Cmax in blood plasma is reached after 1-2 hours.
Distribution. About 17% of amoxicillin binds to blood plasma proteins. Therapeutic concentration is rapidly achieved in blood plasma, lungs, bronchial secretions, middle ear fluid, bile and urine. The concentration of the preparation in the bile exceeds its concentration in the blood by 2-4 times. Amoxicillin poorly penetrates the CSF; however, with inflammation of the meninges (eg, meningitis), the CSF concentration is about 20% of the plasma concentration.
Metabolism. Amoxicillin is partially metabolized, most of its metabolites are inactive.
Excretion. Amoxicillin is excreted primarily by the kidneys. About 60-80% of the dose taken is eliminated after 6 hours unchanged. T1 / 2 of the preparation is 1-1.5 hours. In case of impaired renal function, T1 / 2 of the preparation increases and reaches 8.5 hours with anuria.
T1 / 2 of the preparation does not change with impaired liver function.
Indications
Amoxicillin is indicated for the treatment of such infections:
- acute bacterial sinusitis;
- acute otitis media of the middle ear;
- acute streptococcal tonsillitis and pharyngitis;
- exacerbation of chronic bronchitis;
- community-acquired pneumonia;
- acute cystitis;
- asymptomatic bacteriuria during pregnancy;
- acute pyelonephritis;
- typhoid and paratyphoid fever;
- dental abscesses with widespread cellulite;
- infections of the prosthetic joints;
- eradication of Helicobacter pylori (as part of combination therapy);
- Lyme disease.
The preparation is used to treat and prevent endocarditis.
Application
Doses of amoxicillin are prescribed by the doctor depending on the age, body weight and condition of the patient's kidneys, as well as on the sensitivity of microorganisms and the localization of the infectious process.
Adults and children weighing ≥40 kg
| Indication* | Dose* |
| Acute bacterial sinusitis | 250-500 mg every 8 hours or 750 mg - up to 1 g every 12 hours |
| Asymptomatic bacteriuria during pregnancy |
| Acute pyelonephritis | In the case of severe infections: 750 mg - up to 1 g every 8 hours In acute cystitis, 3 g can be prescribed 2 times a day for 1 day |
| Dental abscess with extensive cellulite |
| Acute cystitis |
| Acute otitis media | 500 mg every 8 hours or 750 mg - up to 1 g every 12 hours In the case of severe infections - 750 mg – 1 g every 8 hours for 10 days |
| Acute streptococcal tonsillitis and pharyngitis |
| Exacerbation of chronic bronchitis |
| Community-acquired pneumonia | 500 mg - up to 1 g every 8 hours |
| Typhoid and paratyphoid fever | 500 mg - up to 2 g every 8 hours |
| Prosthetic joint infections | 500 mg - up to 1 g every 8 hours |
| Prevention of endocarditis | 2 g orally once 30-60 minutes before the procedure |
| Eradication of Helicobacter pylori in combination therapy | 750 mg – 1 g 2 times a day in combination with a proton pump inhibitor (eg omeprazole, lansoprazole) and another antibiotic (eg clarithromycin, metronidazole) for 7 days |
| Lyme disease | The initial stage is 500 mg – 1 g every 8 hours, the maximum dose is 4 g / day in several doses for 14 days (the course of treatment can last from 10 to 21 days). Late stage (systemic lesions) - 500 mg – 2 g every 8 hours, the maximum dose is 6 g / day in several doses for 10-30 days |
* Consideration should be given to official guidelines for appropriate treatment for each indication.
Children weighing 40 kg
| Indication* | Dose* |
| Acute bacterial sinusitis | From 20 to 90 mg / kg / day in several doses ** (do not exceed the dose of 3 g / day). Usually children aged 1-3 years are prescribed 250 mg 2 times a day or 125 mg 3 times a day. at the age of 3–12 years, 250 mg 3 times a day. Attention! The exact daily doses are calculated according to the child's body weight, not his age. |
| Acute otitis media |
| Community-acquired pneumonia |
| Acute sinusitis |
| Acute pyelonephritis |
| Dental abscess with extensive cellulite |
| Acute streptococcal tonsillitis and pharyngitis | From 40 to 90 mg / kg / day in several doses ** (do not exceed a dose of 3 g / day) |
| Typhoid and paratyphoid fever | 100 mg / kg / day in 3 divided doses |
| Prevention of endocarditis | 50 mg / kg body weight orally once 30-60 minutes before the procedure |
| Lyme diseas | Initial stage - 25-50 mg / kg / day in 3 doses for 10-21 days Late stage (systemic lesions) - 100 mg / kg / day in 3 doses for 10-30 days |
Consideration should be given to official guidelines for appropriate treatment for each indication.
** The daily dose of the preparation is recommended to be divided into 2 doses if it approaches the maximum recommended.
Duration of use. In case of mild to moderate infections, take the preparation for 5-7 days. However, if infections are caused by streptococcus, the duration of treatment should be at least 10 days.
In the case of chronic diseases, local infectious lesions, infections of a severe course, the duration of treatment is determined by clinics