Amoxicillin / Amoxycillin

ADMINISTRATION ROUTES:

PO, NG, IV

ALTERNATIVE NAMES:

Apo-Amoxi , Ospamox, Ranbaxy-Amoxi, Ibiamox

ICU INDICATIONS:

1. Treatment of infections caused by susceptible organisms

2. Empirical treatment to cover enterococcus

PRESENTATION AND ADMINISTRATION:

IV:

1 gm vial (powder). Dilute to total of 5 mL if part dose is required (making concentration of 200 mg/mL). Inject slowly over 3-4 minutes or in 100 mL of compatible fluid over 30-60 minutes.

Compatible for 6 hours with Normal saline, 3 hours with Hartmanns, 1 hour with 5% dextrose and glucose and sodium.

Note: 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 250 mg tablets & 500 mg tablets (red/gold, marked APO and strength)

Ospamox capsules 500 mg capules (yellow)

Ospamox suspension (125mg/5 mL and 250 mg/mL)

Ranbaxy-Amoxi (125mg/5 mL and 250 mg/5 mL)

Amoxil paediatric drops (125mg/1.25 mL)

Ospamox paediatric drops (100 mg/mL)

Liquid is preferred for NG administration.

DOSAGE:

IV:

1-2 gm IV QID

PO:

500 mg to 1 gm TDS

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

Dose in renal impairment

Dose in renal replacement therapy

DOSAGE IN PAEDIATRICS:

IV:

Severe infections:

1st week of life 50 mg/kg BD

Otherwise 50 mg/kg QID

CLINICAL PHARMACOLOGY:

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:

Enterococcus faecalis

Staphylococcus species (beta-lactamase-negative strains only). Staphylococci which are susceptible to amoxicillin but resistant to methicillin/oxacillin should be considered as resistant to amoxicillin

Streptococcus pneumoniae

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.

CONTRAINDICATIONS:

1. A history of allergic reaction to any of the penicillins

WARNINGS:

Anaphylaxis

Penicillins are a common cause of anaphylactic reactions

Pseudomembranous colitis

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.

PRECAUTIONS:

General:

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.

Laboratory Tests:

No tests in addition to routine ICU tests are required

Drug/Laboratory Test Interactions:

None noted

IMPORTANT DRUG INTERACTIONS IN ICU:

None of significance

ADVERSE REACTIONS:

Body as a Whole:

Serum sickness like reactions, Anaphylaxis

Digestive System:

Nausea, vomiting, diarrhoea, and haemorrhagic/pseudomembranous colitis. Hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis have been reported.

Nervous System:

Reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions, behavioural changes, and/or dizziness have been reported rarely.

Skin:

Stevens-Johnson Syndrome, exfoliative dermatitus, toxic epidermal necrolysis, acute generalised exanthematous pustulosis, hypersensitivity vasculitis and urticaria have been reported

Haematological System:

Anaemia, including haemolytic anaemia, thrombocytopaenia, thrombocytopenic purpura, eosinophilia, leukopaenia, and agranulocytosis have been reported during therapy with penicillins