Amoxicillin PO, NG, IV
Apo-Amoxi , Ospamox, Ranbaxy-Amoxi, Ibiamox
Treatment of infections caused by susceptible organisms
Empirical treatment to cover enterococcus
1gm vial (powder). Dilute to total of 5ml if part dose is required (making concentration of 200mg/ml). Inject slowly over 3-4 minutes or in 100ml of compatible fluid over 30-60 minutes.
Compatible for 6 hours with normal saline, 3 hours with Hartmanns, 1 hour with D5W and glucose and sodium. (note that amoxicillin is less stable in solutions that contain glucose so it is preferable to avoid these solutions). Store at room temperature
PO / NG:
Apo-Amoxi 250mg tablets & 500mg tablets (red/gold, marked APO and strength), Ospamox capsules 500mg capules (yellow), Ospamox suspension (125mg/5ml and 250mg/ml), Ranbaxy-Amoxi (125mg/5ml and 250mg/5ml), Amoxil paediatric drops (125mg/1.25ml), Ospamox paediatric drops (100mg/ml). Liquid is preferred for NG administration.
1-2gm IV Q6hrly
Severe infections: 1st week of life 50mg/kg 12hrly; otherwise 50mg/kg 6hrly
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY
Dose in renal impairment [GFR (ml/min)]
<10 500mg every 8 hours
10-20 dose as in normal renal function
>20-50 dose as in normal renal function
Dose in renal replacement therapy
CAPD 500mg every 8 hours
HD 500mg every 8 hours
CVVHDF dose as in normal renal function
Amoxicillin is bactericidal against susceptible organisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of cell wall mucopeptide. Amoxicillin has been shown to be active against most strains of the following microorganisms:
Aerobic Gram-Positive Microorganisms:
Staphylococcus spp*. (beta-lactamase-negative strains only).
*Staphylococci which are susceptible to amoxicillin but resistant to methicillin/oxacillin should be considered as resistant to amoxicillin.
Aerobic Gram-Negative Microorganisms:
Escherichia coli (beta-lactamase-negative strains only).
Haemophilus influenzae (beta-lactamase-negative strains only).
Neisseria gonorrhoeae (beta-lactamase-negative strains only).
Proteus mirabilis (beta-lactamase-negative strains only).
Amoxicillin diffuses readily into most body tissues and fluids, with the exception of brain and spinal fluid, except when meninges are inflamed.
A history of allergic reaction to any of the penicillins is a contraindication.
Penicillins are a common cause of anaphylactic reactions
Pseudomembranous colitis has been reported with nearly all antibacterial agents, including amoxicillin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhoea subsequent to the administration of antibacterial agents.
Prescribing Amoxicillin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug resistant bacteria.
No tests in addition to routine ICU tests are required.
Drug/Laboratory Test Interactions
None of significance.
Body as a Whole:
Serum sickness like reactions, Anaphylaxis
Nausea, vomiting, diarrhoea, and haemorrhagic/pseudomembranous colitis. Hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis have been reported.
Reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions, behavioral changes, and/or dizziness have been reported rarely.
Stevens-Johnson Syndrome, exfoliative dermatitus, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, hypersensitivity vasculitis and urticaria have been reported
Anaemia, including haemolytic anaemia, thrombocytopaenia, thrombocytopenic purpura, eosinophilia, leukopaenia, and agranulocytosis have been reported during therapy with penicillins.