Consumer medicine information

Ibiamox

Amoxicillin

BRAND INFORMATION

Brand name

Ibiamox

Active ingredient

Amoxicillin

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Ibiamox.

What is in this leaflet

This leaflet answers some common questions about Ibiamox. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you being administered Ibiamox against the benefits they expect it will have for you.

If you have any concerns about being administered this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.

What IBIAMOX is used for

Ibiamox contains amoxycillin, an antibiotic that belongs to a group of medicines called penicillins. These antibiotics work by killing the bacteria that are causing your infection. Ibiamox, like other antibiotics, will not work against infections caused by viruses such as colds or the flu. This medicine is available only with a doctor's prescription.

Before you are given IBIAMOX

When you must not be given it

Do not use Ibiamox if:

  1. You have an allergy to Ibiamox (amoxycillin) or other penicillins. Symptoms of an allergic reaction may include skin rash, itching, difficulty breathing or swelling.
  2. You have had an allergic reaction to cephalosporin antibiotics. You may have an increased chance of being allergic to Ibiamox if you are allergic to cephalosporins.
  3. The packaging is torn or shows signs of tampering.
  4. The expiry date (EXP) printed on the pack has passed. If you use this medicine after the expiry date has passed, it may not work as well.

If you are not sure whether you should be given Ibiamox, talk to your doctor.

Before you are given it

You must tell your doctor if:

  1. You have any type of allergic reaction to penicillin, amoxycillin or cephalosporin antibiotics. You may have an increased chance of being allergic to Ibiamox if you are allergic to cephalosporins.
  2. You have any allergies to any other medicines or any other substances, such as foods, preservatives or dyes.
  3. You have any other medical conditions, including:
  • asthma, hayfever or hives
  • kidney problems
  • glandular fever (infectious mononucleosis)
  1. You are pregnant or intend to become pregnant. Your doctor will discuss the possible risks and benefits of using Ibiamox during pregnancy.
  2. You are breast-feeding or plan to breast-feed. Your doctor will discuss the possible risks and benefits of taking / using Ibiamox while breast-feeding.

If you have not told your doctor about any of the above, tell them before you are given Ibiamox.

Taking other medicines

Tell your doctor if you are taking any other medicines, including medicines that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Ibiamox. These include:-

  • allopurinol and probenecid, drugs used to treat high levels of uric acid in the blood such as gout and stone formations
  • The contraceptive pill. As with other antibiotics, you may need to use extra birth control methods eg. condoms.
  • Other antibiotics such as tetracyclines, erythromycin, chloramphenicol and gentamicin.
  • Anticoagulants (used to prevent blood clots) such as warfarin.

These medicines may be affected by Ibiamox, or they may affect how well it works. You may need different medicines. Your doctor will advise you.

Your doctor may have more information on medicines to be careful with or to avoid while taking Ibiamox.

How IBIAMOX is given

Ibiamox is diluted and given intramuscularly or intravenously. It must only be given by a doctor or nurse. Your doctor will decide what dose and how long you will receive it. This depends on your infection and other factors, such as your weight.

For most infections, Ibiamox is usually given in divided doses throughout the day.

While you are using IBIAMOX

Things you must do

If the symptoms of your infection do not improve within a few days, or if they become worse, tell your doctor.

If you develop itching with swelling or skin rash or difficulty breathing while you are receiving Ibiamox, do not have any more and tell your doctor immediately.

If you get severe diarrhoea, tell your doctor, pharmacist or nurse immediately. Do this even if it occurs several weeks after Ibiamox has been stopped.

Diarrhoea may mean that you have a serious condition affecting your bowel. You may need urgent medical care. Do not take any diarrhoea medicine without first checking with your doctor.

If you get a sore white mouth or tongue while being treated with or soon after stopping Ibiamox, tell your doctor. Also tell your doctor if you get vaginal itching or discharge. This may mean you have a fungal infection called thrush. Sometimes the use of Ibiamox allows fungi to grow and the above symptoms to occur. Ibiamox does not work against fungi.

If you become pregnant while you are receiving Ibiamox, tell your doctor.

If you are about to start taking any new medicine, tell your doctor and pharmacist that you are receiving Ibiamox.

If you have to have any blood or urine tests, tell your doctor you are being given Ibiamox. It may affect the results of some blood and urine tests.

Tell all the doctors, dentists and pharmacists who are treating you that you are being treated with Ibiamox.

Side effects

Check with your doctor as soon as possible if you have any problems while being treated with Ibiamox, even if you do not think the problems are connected with the medicine or are not listed in this leaflet.

Like other medicines, Ibiamox can cause some side effects. If they occur, most are likely to be minor and temporary. However, some may be serious and need medical attention.

Ask your doctor or pharmacist to answer any questions you may have.

MILD EFFECTS

Tell your doctor or nurse if you notice any of the following that are troublesome or ongoing:

  • diarrhoea (several loose bowel movements per day), indigestion, feeling sick or being sick.
  • soreness of the mouth or tongue
  • overgrowth of yeast infections (thrush).

MORE SERIOUS EFFECTS

Tell your doctor or nurse immediately if you notice any of the following:

  • Wheezing, swelling of the lips/mouth, difficulty in breathing, hayfever, lumpy rash (hives) or fainting. These could be symptoms of an allergic reaction.
  • pain around the site of injection
  • unusual bleeding or bruising
  • yellowing of the skin or eyes
  • dark urine or pale stools
  • difficulty or pain on passing urine.
  • severe diarrhoea.

Some people may get other side effects while being treated with Ibiamox.

Ask your doctor or pharmacist if you don't understand anything in this list.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

After you finish using it

Tell your doctor immediately if you notice any of the following side effects, particularly if they occur several weeks after stopping treatment with Ibiamox:

  • severe stomach cramps or abdominal cramps
  • watery and severe diarrhoea, which may also be bloody
  • fever, in combination with one or both of the above.

These are rare but serious side effects. You may have a rare but serious condition affecting your bowel which may need urgent medical attention.

Do not take any diarrhoea medicine without first checking with your doctor.

How is IBIAMOX stored

Ibiamox should be stored in the pharmacy or on the ward. The powder for injection should be kept in a cool dry place where the temperature stays below 25°C.

Product description

What it looks like:

  • White powder for injection 1g in a vial.

Injection, are available in boxes of 5* & 10 vials.

5* - Not currently marketed.

Sponsor

Juno Pharmaceuticals Pty Ltd
Level 2, 6 Bond Street,
South Yarra,
VIC 3141

AUST R 92765

Date of leaflet preparation: September 2015.

Published by MIMS June 2017

BRAND INFORMATION

Brand name

Ibiamox

Active ingredient

Amoxicillin

Schedule

S4

 

1 Name of Medicine

Amoxicillin sodium.

2 Qualitative and Quantitative Composition

Amoxicillin is a semisynthetic antibiotic and is a member of the penicillinase- stable group of penicillins derived from the penicillin nucleus, 6-aminopenicillanic acid. It is identified chemically as sodium (2S,5R,6R)-6[[(2R)-2-amino-2-(4- hydroxyphenyl)acetyl]amino]-3,3- dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2- carboxylate.
Amoxicillin sodium is a white or almost white powder, very hygroscopic, very soluble in water, sparingly soluble in ethanol, very slightly soluble in acetone.
Ibiamox is a white to off-white powder in a clear glass vial. Each 1 g vial of amoxicillin contains sodium 3.3 mmol.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

1 g powder for injection vial.

4 Clinical Particulars

4.1 Therapeutic Indications

Ibiamox is intended for use where the patient's condition precludes the administration of the oral form of amoxicillin. It is indicated for the treatment of the following infections due to susceptible strains of sensitive organisms.

Note.

Therapy should be guided by bacteriological studies, including sensitivity tests, and clinical response. However, in emergency cases where the causative organism has not been identified, therapy with amoxicillin sodium may be useful. Clinical judgement will decide whether combination with another antibiotic would provide a sufficiently broad spectrum of activity pending sensitivity test results.

Septicaemia (bacterial).

H. influenzae; E. coli (see Section 5.1 Pharmacodynamic Properties, Microbiology); P. mirabilis; Streptococcus; Strep. pneumoniae; Strep. faecalis and Salmonella typhi.

Skin and skin structure.

Staphylococcus (nonpenicillinase producing); Streptococcus; E. coli (see Section 5.1 Pharmacodynamic Properties, Microbiology).

Respiratory, acute and chronic.

H. influenzae; Streptococcus; Strep. pneumoniae; Staphylococcus (nonpenicillinase producing); E. coli (see Section 5.1 Pharmacodynamic Properties, Microbiology).

Genitourinary tract (complicated and uncomplicated), acute and chronic.

E. coli (see Section 5.1 Pharmacodynamic Properties, Microbiology); P. mirabilis and Strep. faecalis.

Gonorrhoea.

N. gonorrhoea (nonpenicillinase producing).

Prophylaxis of endocarditis.

Amoxicillin sodium may be used for the prophylaxis of bacterial endocarditis in individuals at particular risk, such as those with prosthetic heart valves or those who have previously had endocarditis.

4.2 Dose and Method of Administration

Normal renal function.

Upper respiratory tract infections; genitourinary tract infections; skin and soft tissue infections.

Adults.

250 mg every six to eight hours, depending on the patient's condition.

Children (under 20 kg).

20 mg/kg/day in equally divided doses every six to eight hours.
In severe infections or those caused by less susceptible organisms: 500 mg every six to eight hours for adults and 40 mg/kg/day in equally divided doses every six to eight hours for children may be needed.
Lower respiratory tract infections.

Adults.

500 mg every six to eight hours.

Children (under 20 kg).

40 mg/kg/day in equally divided every six to eight hours.
Bacterial septicaemia.

Adults.

In more serious infections in adults, Ibiamox can be given as 1 g every six hours by slow intravenous injection (taking three to four minutes if injecting directly or into drip tube) or by intravenous infusion over a period of 30 minutes to one hour.

Children (under 20 kg).

20 to 40 mg/kg every six hours.
Prophylaxis of endocarditis. See Table 1.

Altered renal function.

In renal impairment the excretion of the antibiotic will be delayed, and depending on the degree of impairment, it may be necessary to reduce the total daily dosage (see Table 2).

Note.

The children's dosage is intended for individuals whose weight will not cause dosage to be calculated greater than that recommended for adults. Children weighing more than 20 kg should be dosed according to the adult recommendations.
It should be recognised that in the treatment of chronic urinary tract infections, frequent bacteriological and clinical appraisals are necessary. Smaller doses than those recommended above should not be used. In stubborn infections, therapy may be required for several weeks. It may be necessary to continue clinical and/or bacteriological follow-up for several months after cessation of therapy.
Treatment should be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic or evidence of bacterial eradication has been obtained.
It is recommended that there be at least ten days treatment for any infection caused by haemolytic Streptococci to prevent the occurrence of acute rheumatic fever or glomerulonephritis.

Directions for use.

Ibiamox should be administered immediately after reconstitution to reduce the microbiological hazard. This product is intended for one patient only. Discard any remaining contents.
In patients for whom sodium intake is of medical concern (patients with congestive heart failure, renal failure, nephritic syndrome, etc.) the additional sodium load of the solution for infusion should be taken into account.

For intravenous injections.

For direct intravenous injection, administer by slow injection (over a period of at least three to four minutes, and preferably 10 to 15 minutes). More rapid administration may result in convulsive seizures.
Amoxicillin sodium is unstable in concentrated solutions and, when prepared for injection, should be administered immediately.

For intramuscular injections.

1 g vial. For intramuscular use, add 5.2 mL Water for Injections B.P and shake vigorously. Doses larger than 500 mg should be divided between multiple injection sites. Alternatively, if pain is experienced on intramuscular injection, dissolve contents in 3 mL of 1% sterile lidocaine (lignocaine) hydrochloride solution and shake vigorously. For intravenous use, dissolve contents in 20 mL Water for Injections B.P. Dilutions in excess of 10 mL should be carried out in the syringe.
Amoxicillin is normally reconstituted with water for injections B.P., however, if pain is experienced on intramuscular injection, a 0.5% solution of procaine hydrochloride or a 1% solution of lidocaine (lignocaine) hydrochloride may be used in place of water for injections B.P.
A transient pink colouration or slight opalescence may appear during reconstitution. Contains no antimicrobial preservative.

Compatibility.

Amoxicillin sodium injection is compatible with commonly used intravenous solutions.
For intravenous infusion amoxicillin injection may be diluted with the following infusion fluids to a concentration of 3% w/v:
Sodium chloride infusion, (normal saline 0.9%), compound sodium chloride (Ringer's solution), M/6 Sodium lactate, compound sodium lactate, (Hartmann's solution), glucose infusion (5%), sodium chloride (0.18%) and glucose infusion (4%).
Since amoxicillin sodium injection is relatively less stable in carbohydrate solutions, (e.g. glucose infusion solution), it is preferable to avoid using them. Amoxicillin sodium may, however, be injected into the drip tubing of such an infusion or incorporated into a small volume of the solution and infused over a period of 30 to 60 minutes.

4.3 Contraindications

Amoxicillin sodium is a penicillin and should not be given to patients with a history of hypersensitivity to β-lactamase antibiotics (e.g. penicillins, cephalosporins).

4.4 Special Warnings and Precautions for Use

Hypersensitivity (anaphylaxis) reactions.

Serious and occasionally fatal hypersensitivity (anaphylaxis) reactions have been reported in patients receiving β-lactam antibiotics. Although anaphylaxis is more frequent following parenteral therapy, it has occurred in patients on oral therapy. Before commencing therapy with any penicillin, careful enquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins or other allergens. If an allergic reaction occurs, appropriate therapy should be instituted and amoxicillin sodium therapy discontinued. Serious anaphylactoid reactions require immediate emergency treatment with adrenaline.
Oxygen, intravenous steroids and airway management, including intubation, should also be administered as indicated.

Pseudomembranous colitis.

Antibiotic associated pseudomembranous colitis has been reported with many antibiotics including amoxicillin sodium. A toxin produced with Clostridium difficile appears to be the primary cause. The severity of the colitis may range from mild to life threatening. It is important to consider this diagnosis in patients who develop diarrhoea or colitis in association with antibiotic use (this may occur up to several weeks after cessation of antibiotic therapy). Mild cases usually respond to drug discontinuation alone. However, in moderate to severe cases appropriate therapy with a suitable oral antibiotic agent effective against Clostridium difficile should be considered. Fluids, electrolytes and protein replacement should be provided when indicated. Drugs which delay peristalsis, e.g. opiates and diphenoxylate with atropine (Lomotil) may prolong and/or worsen the condition and should not be used.
Abnormal prolongation of prothrombin time (increased INR) has been reported rarely in patients receiving amoxicillin and oral anticoagulants. Appropriate monitoring should be undertaken when anticoagulants are prescribed concurrently. Adjustments in the dose of oral anticoagulants may be necessary to maintain the desired levels of anticoagulation.
Amoxicillin sodium has been found to cause dose related renal toxicity in laboratory animals when administered daily as a bolus injection at dose levels of 100 mg/kg/day and above. As the metabolic pattern of amoxicillin sodium in humans appears to be similar to that in animals, the possibility of a nephrotoxic effect from parenteral amoxicillin sodium should be borne in mind.
As with any potent drug, periodic assessment of renal, hepatic and haemopoietic function should be made during prolonged therapy. The possibility of superinfections with mycotic or bacterial pathogens should be kept in mind during therapy. If superinfections occur (usually involving Aerobacter, Pseudomonas or Candida), the drug should be discontinued and/or appropriate therapy instituted.
The possibility of venous irritation, when using that route, must be kept in mind. Caution should be exercised in the treatment of patients with an allergic diathesis. Amoxicillin sodium, an aminopenicillin, is not the treatment of choice in patients presenting with sore throat or pharyngitis because of the possibility that the underlying cause is infectious mononucleosis, in the presence of which there is a high incidence of rash if amoxicillin sodium is used.
Amoxicillin sodium should be given with caution to patients with lymphatic leukaemia since they are especially susceptible to ampicillin induced skin rashes.
During treatment with high doses of amoxicillin sodium, particularly by bolus injection, an adequate fluid intake and urinary output must be maintained. Also, indwelling catheters should be checked regularly for patency since, due to high urinary concentrations, amoxicillin sodium may, at room temperature, precipitate out of solution. The risk of crystalluria should be avoided by maintaining a high urinary output.
Lidocaine (lignocaine) or benzyl alcohol may be used only when administering amoxicillin sodium by the intramuscular route.
The sodium content must be taken into account in patients on a sodium restricted diet if the parenteral administration of high doses is necessary. Each 1 g vial of amoxicillin contains sodium 3.3 mmol.

Impaired renal function.

Dosage should be adjusted in patients with severe and moderate renal impairment (see Section 4.2 Dose and Method of Administration).

Use in the elderly.

No data available.

Paediatric use.

No data available.

Effects on laboratory tests.

Administration of amoxicillin sodium will result in high urine concentrations of amoxicillin sodium. Since high urine concentrations of amoxicillin may result in false positive reactions when testing for the presence of glucose in urine using Clinitest, Benedict's Solution or Fehling's Solution, it is recommended that glucose tests based on enzymatic glucose oxidase reactions (e.g. Clinistix, or Testape) be used.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Probenecid.

Probenecid decreases the renal tubular secretion of amoxicillin sodium. Concurrent use with amoxicillin sodium may result in increased and prolonged blood levels of amoxicillin.

Other antibiotics.

Tetracyclines, erythromycin and chloramphenicol antagonise the action of amoxicillin. Gentamicin should not be mixed with amoxicillin when both drugs are given parenterally as inactivation occurs.

Allopurinol.

The concurrent administration of allopurinol and ampicillin increases substantially the incidence of rashes in patients receiving both drugs as compared to patients receiving ampicillin alone. It is not known whether this potentiation of ampicillin rashes is due to allopurinol or the hyperuricaemia present in these patients. Similar reactions can be expected with amoxicillin sodium.

Oral contraceptives.

In common with other antibiotics, amoxicillin may affect the gut flora, leading to lower estrogen re-absorption and reduced efficacy of combined oral contraceptives. Patients should be warned that amoxicillin may reduce the effectiveness of oral contraceptives.
In the literature there are rare cases of increased international normalized ratio in patients maintained on acenocoumarol or warfarin and a prescribed course of amoxicillin. If co-administration is necessary the prothrombin time or the international normalized ratio should be carefully monitored with the addition or withdrawal of amoxicillin.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category A)
Amoxicillin diffuses across the placenta into the fetal circulation. Animal studies with amoxicillin have shown no teratogenic effects. The product has been in extensive clinical use since 1972 and its suitability in human pregnancy has been well documented in clinical studies. Amoxicillin sodium may be used in pregnancy when the potential benefits outweigh the potential risks associated with treatment.
Following administration of ampicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated oestrone and estradiol has been noted. This effect may also occur with amoxicillin sodium.
 Ampicillin class antibiotics are excreted in the milk; therefore, caution should be exercised when amoxicillin sodium is administered to a breastfeeding woman. An alternative feeding method is recommended to avoid potential sensitisation of the newborn.

Use in labour and delivery.

Oral ampicillin class antibiotics are generally poorly absorbed during labour. Studies in guinea pigs have shown that intravenous administration of ampicillin decreased the uterine tone, frequency of contractions, height of contractions and duration of contractions. However, it is not known whether the use of amoxicillin sodium in humans during labour or delivery has immediate or delayed adverse effects on the foetus, prolongs the duration of labour or increases the likelihood that forceps delivery or other obstetric intervention or resuscitation of the newborn will be necessary.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of this registration.

4.8 Adverse Effects (Undesirable Effects)

As with other penicillins, it may be expected that untoward reactions will be essentially limited to sensitivity phenomena. They are more likely to occur in individuals who have previously demonstrated hypersensitivity to penicillins. Anaphylactic shock is most likely to occur with injected penicillins (see Section 4.4 Special Warnings and Precautions for Use).
The following adverse reactions have been reported as associated with the use of amoxicillin sodium:

Gastrointestinal.

Glossitis, stomatitis, black hairy tongue, nausea, vomiting, diarrhoea. Intestinal candidiasis and antibiotic associated colitis (including pseudomembranous colitis and haemorrhagic colitis) have been reported rarely (see Section 4.4 Special Warnings and Precautions for Use).

Hypersensitivity reactions.

Erythematous maculopapular rash, pruritus and urticaria have been reported. Urticaria has occasionally been reported in association with glandular fever and some other viral diseases. Rarely, skin reactions such as erythema multiforme and Stevens-Johnson syndrome, toxic epidermal necrolysis and bullous, exfoliative dermatitis, acute generalized exanthematous pustulosis (AGEP) and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported. As with other antibiotics, severe allergic reactions including angioneurotic oedema, anaphylaxis, serum sickness, hypersensitivity vasculitis and interstitial nephritis have been reported rarely. Whenever such reactions occur, amoxicillin sodium should be discontinued.

Note.

Urticaria, other skin rashes and serum sickness-like reactions may be controlled with antihistamines and, if necessary, systemic corticosteroids. Anaphylaxis is the most serious reaction experienced (see Section 4.4 Special Warnings and Precautions for Use). A macular rash, which is not believed to be a hypersensitivity reaction, occurs predominantly in patients with infectious mononucleosis 4 to 5 days after beginning therapy with amoxicillin.

Liver.

A moderate rise in AST and/or ALT has occasionally been noted, but the significance of this finding is unknown. As with other β-lactam antibiotics, hepatitis and cholestatic jaundice have been reported rarely.

Renal and urinary tract disorders.

Interstitial nephritis, crystalluria (see Section 4.9 Overdose) has been reported rarely.

Haemic and lymphatic systems.

Reactions such as anaemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia and leucopenia (including severe neutropenia or agranulocytosis) have been reported during therapy with other penicillins. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena. Prolongation of bleeding time and prothrombin time have also been reported rarely.

Central nervous system.

CNS effects have been seen rarely. They include hyperkinesias, dizziness and convulsions. Convulsions may occur in patients with impaired renal function or in those receiving high doses. As the blood brain barrier becomes more permeable in meningitis, toxic symptoms may be precipitated by lower levels of amoxicillin in patients with meningitis.

Infections and infestations.

Mucocutaneous candidiasis has been reported very rarely.
Other: vaginal or oral moniliasis may occur following the use of antibiotics.
Ninety percent of all adverse events to amoxicillin recorded in the Australian Adverse Drug Reaction System relate to the skin (rash, pruritus and urticaria).

Miscellaneous.

Superficial tooth discolouration has been reported very rarely in children. Good oral hygiene may help to prevent tooth discolouration as it can usually be removed by brushing.

Injection site.

Pain may be experienced at the site of intramuscular injection and phlebitis at the site of intravenous injection.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at http://www.tga.gov.au/reporting-problems.

4.9 Overdose

Gastrointestinal effects such as nausea, vomiting and diarrhoea may be evident and symptoms of water/electrolyte imbalance should be treated symptomatically. During the administration of high doses of amoxicillin sodium, adequate fluid intake and urinary output must be maintained to minimize the possibility of amoxicillin crystalluria. Amoxicillin crystalluria, in some cases leading to renal failure, has been observed (see Section 4.4 Special Warnings and Precautions for Use).
As with other penicillins, amoxicillin in overdosage has the potential to cause neuromuscular hyperirritability or convulsive seizures. As the blood brain barrier becomes more permeable in meningitis, toxic symptoms may be precipitated by lower levels of amoxicillin in patients with meningitis.
Amoxicillin sodium can be removed from the circulation by haemodialysis. General supportive measures should be instituted.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Microbiology. Amoxicillin sodium is similar to ampicillin in its bactericidal action against Gram positive and Gram negative susceptible organisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of the cell wall mucopeptide.
It is active in vitro against most strains of Haemophilus influenzae*, Neisseria gonorrhoeae*, Neisseria meningitidis, Escherichia coli*, Proteus mirabilis* and Salmonellae. Because amoxicillin sodium does not resist destruction by penicillinase, it is not active against penicillinase producing organisms, particularly penicillinase producing staphylococci. All strains of Pseudomonas species, Klebsiella species, Enterobacter species, indole positive Proteus species, Serratia marcescens, Citrobacter species, penicillinase producing N. gonorrhoeae and penicillinase producing H. influenzae are resistant. In vitro studies have demonstrated the susceptibility of most strains of the following Gram positive bacteria: alpha and beta haemolytic streptococci, Diplococcus pneumoniae, nonpenicillinase producing staphylococci and Streptococcus faecalis. These organisms are susceptible to amoxicillin sodium at serum concentrations, which may be expected following the recommended doses. However, some of the organisms were susceptible to amoxicillin sodium only at concentrations achieved in the urine (see Section 4.1 Therapeutic Indications).

Note.

*Activity refers only to beta-lactamase negative strains.
Escherichia coli isolates are becoming increasingly resistant to amoxicillin sodium in vitro due to the presence of penicillinase producing strains.
Strains of gonococci which are relatively resistant to benzylpenicillin may be sensitive to amoxicillin sodium.
The following in vitro data are available, but their clinical significance is unknown.
In vitro data for amoxicillin sodium vs. clinical pathogens (see Table 3).
A positive β-lactamase test predicts resistance to penicillin, ampicillin and amoxicillin sodium (see Table 4).

Breakpoints.

Streptococcus pneumoniae: S ≤ 2 microgram/mL; I = 4 microgram/mL; R ≥ 8 microgram/mL.

Note.

Because amoxicillin sodium has greater in vitro activity against Strep. pneumoniae than does ampicillin, the majority of S. pneumoniae strains with intermediate susceptibility to ampicillin are fully susceptible to amoxicillin sodium.

Susceptibility tests.

Dilution or diffusion techniques, either quantitative (MIC) or breakpoint, should be used following a regularly updated, recognised and standardised method (e.g. ATCC (January 2007, Vol 27) and NCCLS (National Committee for Clinical and Laboratory Standards) included following breakpoints information for Streptococcus pneumoniae (see Table 5).
Standardised susceptibility test procedures require the use of laboratory control microorganisms to control the technical aspects of the laboratory procedures.
A report of "susceptible" indicates that the pathogen is likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable. A report of "intermediate" indicates that the result should be considered equivocal, and if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides a buffer zone, which prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of "resistant" indicates that the pathogen is not likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable; other therapy should be selected.

Note.

The prevalence of resistance may vary geographically for selected species and local information on resistance is desirable, particularly when treating severe infections. This information gives only an approximate guidance on probabilities whether organisms will be susceptible to amoxicillin sodium.

Cross resistance.

Other β-lactams, β-lactam/ β-lactamase inhibitor combinations and cephalosporins.

Resistance mechanisms.

Production of penicillinase, altered penicillin binding proteins.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Absorption.

Following intramuscular injection of amoxicillin 250 or 500 mg, peak serum levels, of approximately 5.5 microgram/mL and 10 microgram/mL are achieved within 60 minutes of injection and correspond to the peak values obtained after the same dose given orally.
Absorption from the intramuscular site is almost complete.
Following intravenous injection over a three to four minute period, serum levels at one hour were similar to those seen at one hour after the same dose given intramuscularly. Serum levels immediately after the intravenous injection were, however, higher. The serum half-life, measured as unchanged (active) antibiotic in the excretory phase, is approximately one hour in the presence of normal renal function, rising to about seven hours with a creatinine clearance of 13 mL/minute without dialysis. The elimination half-life does not appear to change until creatinine clearance reaches approximately 30 mL/minute. In patients with a creatinine clearance of 10 mL/minute, the elimination half-life has been shown to vary between 7.5 and 21 hours after a 2 g intravenous dose.

Distribution.

In keeping with other penicillins, penetration into the CSF is poor in the absence of inflammation. Some penetration occurs through inflamed meninges, but maximum CSF levels are very much lower than peak serum levels.
Bile levels vary with the functional integrity of secretory mechanisms, being absent in the presence of biliary tract obstruction.

Protein binding.

Amoxicillin sodium is not highly bound to human serum protein. The degree of binding as measured by ultrafiltration or equilibrium dialysis is 17%.

Excretion.

The major route of excretion is renal (by glomerular filtration and tubular secretory mechanisms). The secretory mechanisms may be inhibited by the concurrent administration of probenecid, leading to prolongation and some elevation of serum levels.
Approximately 70% of a dose administered by intramuscular or rapid intravenous injection will be excreted unchanged by this mechanism in the presence of normal renal function over a six hour period, and approximately 20% will be excreted as the penicilloic acid derivative in the same time. In patients with renal failure, renal excretion falls in relation to the glomerular filtration rate (GFR) but therapeutic levels are still maintained in the urine.
Results of studies in humans, employing thin layer chromatography and bioautography, show that amoxicillin is not changed in vivo into substances with antibacterial activity. There appears to be only one metabolic breakdown product, namely, penicilloic acid.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

See Section 2 Qualitative and Quantitative Composition.

6.2 Incompatibilities

Amoxicillin sodium should not be mixed with blood products or proteinaceous fluids such as protein hydrolysates, nor with intravenous lipid emulsions.

6.3 Shelf Life

36 months.
In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Dry powder.

Store below 25°C. Protect from moisture. Protect from light.

6.5 Nature and Contents of Container

Clear type III glass vial containing a white or almost white powder containing amoxicillin sodium, equivalent to 1 g of amoxicillin; sealed with a rubber closure and a flip off top.
Pack size: 1 g (5* and 10' vials). 5* Not currently marketed.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of in accordance with local requirements.

6.7 Physicochemical Properties

Chemical name: sodium (2S,5R,6R)-6-[[(2R)-2-amino-2-(4-hydroxyphenyl)acetyl]amino]- 3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate.

Chemical structure.


CAS number.

[36242-77-8].
Molecular weight: 387.4.
Molecular formula: C16H18N3NaO5S.

7 Medicine Schedule (Poisons Standard)

Schedule 4 - Prescription only Medicine.

Summary Table of Changes