| Gram-positive bacteria | Gram-negative bacteria |
| Staphylococcus aureus (penicillin*-sensitive) | Neisseria gonorrhoea* |
| Streptococcus pyogenes | Neisseria meningitidis |
| Streptococcus viridans* | Haemophilus influenzae** |
| Streptococcus faecalis | Bordetella pertussis |
| Diplococcus pneumoniae* | Escherichia coli* |
| Corynebacterium species* | Salmonella typhi |
| Clostridium species* | Salmonella species |
| Bacillus anthracis* | Shigella species |
| Proteus mirabilis | |
| Brucella species |
*
Sensitivity tests must be performed,
** except type b-strains causing meningitis in
children.
| (ii) Bactericidal Action | |||
| Amoxycillin exerts a rapid bactericidal activity at normal dosage levels against all susceptible organisms. | |||
(b) Absorption
| Amoxycillin is extremely well absorbed orally. A single 250 mg oral dose achieves an average peak serum level virtually equal to that achieved by IM injection viz. 5,3 µg/mL oral and 5,6 µg/mL IM. The peak serum level is achieved within 1,5 ––2 hours after oral and 15 minutes after IM or IV administration. | |
| After oral administration, there is no significant difference between the peak serum levels in fasting and non-fasting subjects. The presence of food does not interfere with the absorption of Amoxil. Amoxil may, therefore, be taken with meals. | |
| There is a linear/dose response in peak serum levels after both oral and parenteral administration. |
(c) Distribution
| (i) | Sputum: The concentration of amoxycillin in sputum does not decrease as occurs with ampicillin as purulence subsides. | ||
| (ii) | Bile: Amoxil is present in bile obtained from a common bile duct drain of a healthy gall-bladder, however, biliary levels are lower when the gall-bladder is diseased and absent in the presence of biliary tract obstruction. | ||
| (iii) | Urine: the average concentration of Amoxil in urine collected during the first six hours after 250 mg oral dose, is 580 mg/mL. | ||
(d) Excretion
| (i) | Renal: Approximately 60% of an oral dose of Amoxycillin is excreted unchanged in the active form into the urine within six hours. Approximately 70% - 80% of an intramuscular dose and 90% of an intravenous dose is excreted unchanged in the active form, into the urine within 12 hours. | |
| (ii) | Biliary: A variable percentage of Amoxil is excreted into the bile. |
(e) Probenecid
| Even higher Amoxil serum levels may be achieved after oral administration to patients with normal renal function, by the simultaneous administration of a renal blocking agent such as probenecid. Probenecid should not be given in the presence of abnormal renal function. No data on the effect of probenecid on parenteral Amoxil are yet available. |
INDICATIONS:
Infections caused by susceptible, non-penicillinase-producing organisms including:
| Upper respiratory tract infections | Lower respiratory tract infections |
| Otitis media | Typhoid Fever |
| Upper urinary tract infections | Lower urinary tract infections |
| Skin and soft tissue infections | Gastro-intestinal tract infections |
| Gonorrhoea | Non-specific urethritis |
CONTRA-INDICATIONS:
Allergy to penicillins or any of the cephalosporins is an absolute contra-indication
to the use of Amoxil.
WARNINGS:
Serious and occasionally fatal hypersensitivity (anaphylactoid) reactions have been
reported in patients on penicillin therapy. Although anaphylaxis is more frequent
following parenteral therapy, it has occurred in patients on oral penicillins. Before
commencing therapy with any penicillin, careful inquiry should be made concerning previous
hypersensitivity reactions to penicillins, cephalosporins, or other allergies.
If an allergic reaction occurs, appropriate therapy should be instituted and amoxycillin
therapy discontinued.
There is insufficient evidence at present to show that Amoxil penetrates into the
cerebro-spinal fluid in therapeutic quantities and it should, therefore, not be used in
the treatment of cerebro-spinal infections.
DOSAGE AND DIRECTIONS FOR USE:
The average adult dose for Amoxil is 750 mg ––1,5 g/day, but in
serious infections up to 6 g daily has been administered.
| (a) | General dosages: | |
| (i) | Oral | |
| Adults: 250 mg ( 1 x 250 mg capsule or 5 mL of 250 mg/5 mL syrup) three times a day. | ||
| *Children 2 ––10 years: 125 mg (5 mL of 125 mg/5 mL syrup) three times a day. | ||
| *Children 6 months ––2 years: 125 mg (one full pipette of paediatric suspension or 5 mL of 125 mg/5 mL syrup) three times a day. | ||
| *Infants 0 ––6 months: 62,5 mg (half pipette measure of paediatric suspension) three times a day. | ||
| *Premature infants 1,0 ––2,5 kg: 30,0 ––62,5 mg (quarter to half pipette measure of paediatric suspension) once daily for the first 1 ––2 weeks depending on the size and maturity of the infant, thereafter dose may be given 2 ––3 times daily. | ||
| In severe infections these dosages may be increased. | ||
| (ii) | Parenteral | |
| Adults: Mild to moderate infections: 250 mg ––500 mg IV or IM three times a day. | ||
| Severe infections: 500 mg ––2 g IV 4 ––6 times a day. | ||
| In particularly severe infections doses of up to 3 g may be administered by rapid intravenous infusion over a period of 30 minutes. This may be repeated every four hours. | ||
| Children 2 ––10 years: Half the adult dose. * | ||
| Children up to 2 years: Quarter the adult dose. * | ||
| * This should correspond to a daily dosage of 35 ––100 mg/kg. | ||
NOTE:
| (1) | Patients with renal insufficiency may possibly require a reduced dose. |
| (2) | During treatment with high doses of Amoxil particularly by bolus injection an adequate fluid intake and urinary output must be maintained. Indwelling catheters should be checked regularly for potency since at room temperature high urinary concentration of Amoxil may precipitate out of solution. |
Incompatibility:
Amoxil should not be added to infusion bottles containing proteinaceous fluids such as
protein hydrolysates, intravenous lipid emulsions, blood or plasma.
Specific dosages: (oral or parenteral)
| Indications | Daily Dosages* | Duration | ||
| Adults | Children | |||
| Gastro-intestinal tract infections | 1 ––2 g | –– | 4 ––5 days | |
| Acute Typhoid Fever | 4 g | –– | 14 days | |
| –– | 100 mg/kg | 21 days | ||
| Gonorrhoea | 2 ––3 g | –– | Stat | |
* Either oral or parenteral administration.
SIDE EFFECTS AND SPECIAL PRECAUTIONS:
Precautions:
Allergic reactions presenting as a skin rash, pruritus and urticaria have been
reported less frequently. Other reactions including angio-oedema, anaphylaxis, erythema
multiforma, Stevens-Johnson syndrome and exfoliative dermatitis may occur in exceptional
cases. If a skin rash occurs, treatment should be discontinued. In the event of an
anaphylactic reaction, immediate treatment with adrenalin, oxygen, corticosteroids and
antihistamines should be initiated.
Blood:
Blood dyscrasias have been reported less frequently. These reactions are usually
reversible on discontinuation of therapy and are believed to be hypersensitivity
phenomena.
Liver:
A moderate rise in SGOT and for SGPT has been reported in exceptional cases.
At high doses of parenteral Amoxil, caution must be exercised in treating patients
with dehydration or oliguria because of the possibility of cristalluria.
The use of this antibiotic may lead to the appearance of resistant strains of organisms
and sensitivity testing should, therefore be carried out wherever possible, to ensure the
appropriateness of the therapy.
Gastro-intestinal disturbance including diarrhoea, nausea and vomiting have been reported.
Pseudo-membranous colitis has been reported, if this condition occurs, treatment should be
discontinued and appropriate therapy, e.g. vancomycin, should be initiated.
The dose should be reduced in patients with renal failure. Periodic assessment of renal,
hepatic, and haematopoietic function should be made during prolonged therapy. Prolonged
use may also occasionally result in overgrowth of non-susceptible organisms
Amoxycillin should preferably not be used in patients with infectious mononucleosis and
should also be used with caution in patients glandular fever, lymphatic leukaemia, and
patients treated with allopurinol since they are especially susceptible to
ampicillin-induced skin rashes.
Due to Amoxycillin's effect on intestinal flora, the absorption of other medicine may be
affected. Amoxycillin may reduce the efficacy of oral contraceptives and patients should
be warned accordingly.
The absorption of concurrently administered digoxin may be increased during treatment with
Amoxycillin.
Caution is needed when administering Amoxycillin to patients with syphilis, as the
Jarisch-Herxheimer reaction may occur in these patients
Pregnancy and Lactation:
Animal reproduction studies have failed to demonstrate a risk to the foetus. There are
no adequate and well controlled studies in pregnant women.
Amoxil is excreted in breast milk, and should be used with caution when
administered to lactating women.
KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT:
If encountered, gastro-intestinal symptoms and disturbance of the fluid and
electrolyte balance may be evident. They may be treated symptomatically and supportive
with attention to the water/electrolyte balance. In the absence of an adequate fluid
intake and urinary output, crystalluria is a possibility and the antibiotic may be removed
from the circulation by haemodialysis.
Oral administration can cause gastro-intestinal symptoms such as transient diarrhoea,
nausea and colic which are dose related and a result of local irritation not toxicity.
