AMPICLOX (Ampicillin-Cloxacillin)


Ampiclox is a broad spectrum formulation of Ampillicin Trihydrate (6 amino-penicillianic acid) and Cloxacillin Sodium (isoxazolyl penicillin) having a broad spectrum activity against a wide range of Gram-negative and Gram-positive bacteria.



Each capsule contains Ampicillin Trihydrate BP equivalent to Ampicillin 250mg and Cloxacillin Sodium BP equivalent to Cloxacillin 125mg.


Each 5ml of re-constituted suspension contain: Ampicillin Trihydrate BP equivalent to Ampicillin 125mg and Cloxacillin Sodium BP equivalent to Cloxacillin 125mg.


Ampiclox is active against a wide range of Gram-negative and Gram-positive bacteria including Streptococci,
Staphylococci (penicillinase producing strains), Haemophilus influenza, Escherichia coli, Proteus mirabilis,
Salmonella species and Neisseria species.


Both Ampicillin and Cloxacillin are bacterial agents.

They act by interfering with synthesis of the peptidoglycan layer of the cell wall,
which normally protects the bacterium from its environment. Defective wall synthesis renders the
cell incapable of withstanding the osmotic gradient between the cell and its environment so
that it swells and explodes.

Synergy has been demonstrated between Ampicillin and Cloxacillin against some beta lactamase producing organisms.



Ampicillin is moderately well absorbed from the gastro-intestinal tract after oral administration.
Food can interfere with the absorption of Ampicillin so doses should be taken 30 minutes to an hour before meals.

Peak concentration in plasma are obtained in about 1 to 2 hours and following a dose of 500mg by mouth are
reported to range from 2 to 6 g/ml. It diffuses across the placenta into the foetal circulation and
concentration can be detected in the milk of nursing mothers. There is little diffusion into the
cerebrospinal fluid except when the meninges are inflamed, when higher concentration can be achieved.

About 20% is bound to plasma protein and the plasma half-life is a bout 1-2 hours, but this may increase
in neonates and the elderly. In renal failure half-lives of 7 to 20 hours have been reported.
Renal clearance of Ampicillin occurs partly by glomerular filtration and partly by tubular secretion.
About 20 to 40% of an orally administered doses is excreted unchanged in the urine in 6 hours, urinary
concentration ranges from 0.25 to 1mg/ml following a dose of 500mg.


Cloxacillin sodium is incompletely absorbed from the gastrointestinal tract after oral administration;
the absorption is further reduced by the presence of food in the stomach.
After oral dose of 500mg, a peak plasma concentration of 7 to 14g/ml is obtained in fasting subject
in 1 to 2 hours. About 94% of Cloxacillin in the circulation is bound to the plasma proteins.

Cloxacillin has been reported to have a plasma half-life is prolonged in neonates.
Cloxacillin diffuses across the placenta into the foetal circulation and is excreted
in breast milk. Cloxacillin is metabolised to a limited extend, and the unchanged drug
and metabolites are excreted in the urine by glomerular filtration and renal tubular secretion.


Ampiclox is indicated in the treatment of a variety of infections due to susceptible organisms:

  • Respiratory tract infections
  • Urinary tract infection
  • Septicaemia
  • Otitis media
  • Infective Endocarditis
  • Ear Nose and Throat infections
  • Gastro-intestinal infections
  • Skin and soft tissue infections
  • Pelvic infections
  • Orthopaedic infections.


The doses of Ampiclox will depend on the severity of the disease, the age of the patient and their renal function. The dose should be reduced in renal failure. The usual dose of Ampiclox is as follows:

  • Adult: 500mg to 1g every 6 hourly or more frequently according to severity of infection.
  • Children: Up to 2 years: 250mg (5ml of syrup) every 6 hours.
  • Children 2 – 10 years, (5 – 10ml of syrup) every 6 hours


Ampiclox is contraindicated in patients with a history of allergic reactions to penicillins.


Side effects may include diarrhoea, indigestion or occasional rashes, either urticarial. An erythematous rash may be caused in patients with glandular fever in which case it is advisable to discontinue treatment.


Ampiclox should preferably not be given to patients with infectious mononucleosis since they are especially susceptible to skin rashes, patients with lymphatic leukaemia and patients with hyperuncaemia being treated with allopurinol may be at increased risk of developing skin rashes.

Ampicillin may decrease the efficacy of oestrogen containing oral contraceptives and it may also affect the absorption of other drugs due to its effect on the gastro-intestinal flora.