Pharmacological properties: semisynthetic penicillin with a broad spectrum of bactericidal activity against many gram-positive bacteria: staphylococci, not producing penicillinase, Streptococcus spp. (alfa- and beta- hemoliticini), Streptococcus pneumoniae, Streptococcus faecalis, Clostridium tetani, Listeria monocytogenes; gram-negative bacteria: Neisseria gonorrhoeae, Neisseria meningitides, Haemophilus influenzae, Haemophilu pertussis, Eschiricihia coli, Proteus mirabilis, Salmonella spp. , Shigella spp. Actinomyces israeli. Pseudomonas spp., Klebsiella spp., Enterobacter, Mycoplasma, Chlamydia, Rickettsia are resistant to it.
It acts through the inhibition of peptidoglycanesynthetase of the bacterial wall and bacterial cell lysis.
Amoxicillin is similar to ampicillin in its bactericidal action against susceptible organisms during the stage of active multiplication when they are not producing β-lactamase.
Unlike ampicillin, amoxicillin is assimilated well by the organism, it does not irritate the mucous membrane of alimentary canal, creates a higher concentration in the blood. Amoxicillin is stable in the presence of gastric acid and is rapidly absorbed after oral administration.
- Contraindications and cautions:
Amoxicillin is appropriate for the treatment of penicillin-allergic patients, Herpes Virus and for Infectious Mononucleosis.
Amoxicillin is active in infections caused by Streptococci, staphylococci, gonococcus, mycoplasm, etc.
It is assimilated and absorbed well by the organism. It doesn’t irritate the path of gastrointestinal mucous membrane. It is stable in the presence of gastric acid.
Indications: Angina, Otitis media, acute and chronic bronchitis, pneumonia, pneumonia, cysts, gonorrhea, stomach ulcers and stomach cancer, cholecystitis, dental infection.
It is indicated in the treatment of infections - due to Streptococcus, Staphylococcus (not generating beta-lactamase) and H. influenzae; infections of the skin and skin structure - due to Staphylococcus spp. and E. coli; infections of the lower respiratory tract - due to Staphylococcus(not generating beta-lactamase), Streptococcus and H. influenzae; gonorrhea acute uncomplicated (ano-genital and urethral infections) – due to N. gonorrhea (males and females); duodenal ulcer – due to Helicobacter pylori; infections of the biliary tracts; infections of the genitourinary tract.
Probenecid decreases the renal tubular secretion of amoxicillin.Amoxicillin increase the effect of anticoagulants.
- Method of application:
Adults and youngster dose - 250 mg every 8 hours. The maximum dose is 4,5g/day.
For children it is 20mg/kg/day in 3 divided doses every 8 hours (neonates – 62, 5mg/3 times per day, infants aged – 125 mg/ 3 times per day). The dose may be doubled in severe infections. In infections of the lower respiratory tract: Adults 500 mg every 8 hours; Children 40 mg/kg/day in 3 divided doses. In acute, uncomplicated Gonorrhea (in males and females): 3g as single oral dose.
People with such diseases as septicemia, meningitis, and endocarditis can use amoxicillin.
Adults: 6g/day. Infants and neonates: 150 mg/kg/day.
In typhoid fever: adults 2-4 g/day within 14 days, children 2g/day within 21 days.
Patients with enterocolitis should receive 1-2g/day.
In case of overdose the patient can have an attempt at emesis, nausea and diarrhea.
The treatment: symptomatic therapy. In severe infections hemodialysis is carried out.
- Special precautions:
The risk of toxic reactions to this drug may be greater in patients with incompletely developed renal function, in neonates and young infants. It can provoke the infections with Pseudomonas, Enterobacter or Candida. If superinfections occur, amoxicillin should be discontinued and appropriate therapy instituted.
These hypersensitivity reactions may be controlled with antihistamines and, if necessary, systemic corticosteroids and oxygen.
- Side effects:
As with other penicillins, it may be expected to the untoward reactions. The following adverse reactions have been reported as associated with the use of penicillins: Nausea, vomiting, diarrhea, stomatitis, anemia, including hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia and dizziness; reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions and behavioral changes.
Serum sickness–like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, hypersensitivity vasculitis and urticaria have been reported.