Amoxicillin: description of the drug


Amoxicillin is a broad-spectrum antibiotic from the group aminopenicillins, used to treat  bacterial infections, caused by susceptible microorganisms.

Active against such microorganisms as Gram-positive bacteria  Staphylococcus spp. (with the exception of strains producing penicillinase), Streptococcus spp., (including Streptococcus pneumoniae), Bacillus anthracis, Corynebacterium diphtheriae (most strains), Erysipelothrix rhusiopathiae, Listeria monocytogenes; gram-negative bacteria: Borrelia burgdorferi, Escherichia coli, Haemophilus influenzae, Klebsiella spp. , Leptospira spp., Moraxella (Branhamella catarrhalis) (most strains), Neisseria gonorrhoeae, Neisseria meningitidis; Proteus mirabilis, Salmonella spp., Shigella spp., Treponema pallidum, Treponema pertenue; anaerobic bacteria: Eubacterium spp., Clostridium perfringens, Clostridium tetani , Peptostreptococcus spp., Peptococcus spp., Streptococcus faecalis.


After oral amoxicillin is well absorbed, reaching maximum  concentration in the blood serum within 2 hours after acceptance. Excreted unchanged by the kidney (60 – 70%).
For adults and children over 10 years dosing regimens are 250 mg every 8 hours, 500 mg every 8 hours, 500 mg every 12 hours or 875 mg every 12 hours, depending on the type and severity of infection.

Side effects:

• allergic reactions (urticaria, erythema, angioedema, rhinitis, conjunctivitis, and in rare cases, fever, joint pain, eosinophilia, and very rarely anaphylactic shock);
• from the digestive tract (nausea, vomiting, diarrhea), development of superinfections.
When it is used in combination with metronidazole are possible:
• nausea, vomiting, anorexia, diarrhea, constipation, abdominal pain, glossitis, stomatitis, in rare cases, hepatitis, pseudomembranous colitis, interstitial nephritis, hematopoietic disorders;
• long-term use of high doses: dizziness, ataxia, loss of consciousness, depression, recurrent neuropathy, seizures.

Drug interactions:

Amoxicillin reduces the effect of estrogen contraceptives. Enhances the absorption of digoxin. Decreases clearance and increases the toxicity of methotrexate. Excretion by the kidneys is slowed by aspirin, indomethacin, sulfinperazonom, oxyphenbutazone, phenylbutazone.