Chemically it is (2S,5R,6R)—6—[(R)—(—)—2—amino—2—(p—hydroxyp henyl)acetamido]—3,3—dimethyl—7—oxo—4—thia—1 —azabicyclo[3.2.0]heptane—2—carboxylic acid trihydrate.
C16H19N3O5S . 3H20
Amoxicillin is a semi—synthetic aminopenicillin of the beta—lactam group of antibiotics which exerts a bactericidal effect against many Gram—positive and Gram—negative microorganisms. Amoxicillin is not effective against beta— lactamase producing organisms.
Amoxicillin is rapidly absorbed from the gut to an extent of 72—93%. Absorption is independent of food intake. Peak blood levels are achieved 1—2 hours after administration. After 250 and 500mg doses of amoxicillin, average peak serum concentrations of 5.2mcg/ml and 8.3mcg/ml respectively have been reported. Amoxicillin diffuses readily into most body tissues and fluids, with the exception of the brain and spinal fluid. Approximately60—70% of amoxicillin is excreted unchanged in urine during the first 6 hours after administration of a standard dose. The elimination half—life is approximately 1 hour.
Amoxicillin is indicated in the treatment of infections due to susceptible (ONLY— lactamase—negative) strains of the designated microorganisms in the conditions listed below: Infections of the ear, nose, and throat due to Streptococcus spp. (— and —hemolytic strains only), S. pneumoniae, Staphylococcus spp., or H. Influenzae; Infections of the genitourinary tract; Infections of the skin and skin structure, Infections of the lower respiratory tract.
Administration and Dosage
Upper Respiratory Tract Infections, Genito—Urinary Tract Infections, Skin And Soft Tissue Infections
Aduttls: 250mg every 8 hours
Children (under 20kg): 25mg/kg/day in equally divided doses every 8 hours.
In severe infections of those caused by less susceptible organisms, 500mg every 8 hours for adults and 50mg/kg/day in equally divided doses every 8 hours for children may be needed.
Lower Respiratory Tract Infections:
Adults: 500mg every 8 hours.
Children (under 20kg): 50mg/kg/day in equally divided doses every 8 hours.
High Dosage Therapy (maximum recommended oral dosage 6g daily in divided doses).
An adult dosage of 3g twice daily is recommended in appropriate cases for the treatment of severe or recurrent purulent infection of the respiratory tract.
There are report occasionally that occurs side effects including nausea, diarrhea, abdominal pain, malaise, headache and swirl and so on, however, the normal treatment can continue going.
Amoxicillin is a penicillin and should not be given to patients with a history of hypersensitivity to beta—lactam antibiotics (eg. penicillins, cephalosporins).
• Before initiating therapy with amoxicillin, careful enquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins. Cross—sensitivity between penicillins and cephalosporins is well documented.
• Dosage should be adjusted in patients with renal impairment
• Amoxicillin should be avoided if infectious mononucleosis is suspected since the occurrence of a morbilliform rash has been associated with this condition following the use of amoxicillin.
• Prolonged use may occasionally result in overgrowth of non—susceptible organisms.
• Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use of amoxicillin and probenecid may result in increased and prolonged blood levels of amoxicillin.
• Choramphenicol, macrolides, sulfonamides, and tetracy—clines may interfere with the bactericidal effects of penicillin.
• Concurrent administration of allopurinol during treatment with amoxicillin can increase the likelihood of allergic skin reactions.
• In common with other broad spectrum antibiotics, amoxicillin may reduce the efficacy of oral contraceptives and patients should be warned accordingly.
Use in pregnancy
The safety of this medicinal product for use in human pregnancy has not been established by well controlled studies in pregnant women. Reproduction studies have been performed in mice and rats at doses up to ten times the human dose and these studies have revealed no evidence of impaired fertility of harm to the foetus due to amoxicillin. Amoxicillin may be used in pregnancy when the potential benefits outweigh the potential risks associated with treatment.
Store in a cool dry place below 30°C and protect from light.