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Amfipen LA 100mg/ml Antibiotic Injection

  • 80ml Bottle £13.49

Amfipen LA 100mg/ml is an injectable antibiotic containing ampicillin in a formulation designed to give at least 48 hours cover from a single injection. It can be used in dogs, cats, cattle, pigs and sheep for infections sensitive to ampicillin. It is not suitable for use in horses due to the localised reaction which develops around the injection site. It should not be used in small herbivores due to the risk of serious digestive upset.


A sterile non-aqueous suspension containing 100 mg ampicillin (as Anhydrous Ampicillin) per ml, with aluminium stearate producing a prolongation of antibiotic activity for at least 48 hours following injection. Also contains Dodecyl Gallate 87.5 mg/ml as an antioxidant.


The treatment of diseases or secondary infections due to the following bacteria sensitive to ampicillin in dogs, cats, cattle, pigs and sheep and where prolongation of activity from a single injection is required: Streptococcus spp., Actinomyces pyogenes, Mannheimia haemolytica, Pasteurella multocida, Erysipelothrix rhusiopathiae, Staphylococcus aureus and Staphylococcus spp.

Dosage and administration

Cattle and sheep 15 mg per kg bodyweight, pigs 25 mg per kg bodyweight, by intramuscular injection.

Dogs 15 mg per kg bodyweight, cats 20 mg per kg bodyweight, by subcutaneous injection.


500 kg

75   ml


50 kg

7.5 ml


50 kg

12.5 ml


10 kg

1.5 ml


5 kg

1  ml

Clean the area of the injection site and swab with spirit. Do not use the same injection site more than once during a course of treatment.

Do not administer more than 10 ml per injection site in pigs and sheep and 20 ml in cattle.

Treatment may be repeated once after 48 hours.

Contra-indications, warnings, etc

This product is not effective against beta-lactamase producing organisms.

Do not administer to animals known to be sensitive to penicillins, nor to rabbits, hamsters or guinea pigs. Severe disturbances of the intestinal bacterial flora may occur.

Treatment of horses is not advised due to the likelihood of severe local reactions at the injection site.

Treatment of dogs and cats intramuscularly is to be avoided as this may prove painful.

Local swelling at the injection site may occur in dogs, this usually regresses spontaneously in 2–4 days.

Withdrawal periods

Not to be used in animals producing milk for human consumption.

Animals must not be slaughtered for human consumption during treatment. Cattle, sheep and pigs may be slaughtered for human consumption only after 60 days from the last treatment.

Operator warning

Penicillins and cephalosporins may cause hypersensitivity (allergy) following injection, inhalation, ingestion or skin contact. Hypersensitivity to penicillin may lead to cross reactions to cephalosporins and vice versa. Allergic reactions to these substances are occasionally serious.

1.Do not handle this product if you know you are sensitised, or if you have been advised not to work with such preparations.

2.Handle this product with great care to avoid exposure, taking all recommended precautions.

3.If you develop symptoms following exposure, such as a skin rash, you should seek medical advice and show the doctor this warning. Swelling of the face, lips or eyes or difficulty with breathing, are more serious symptoms and require urgent medical attention.

Wash hands after use.

For animal treatment only. Keep out of reach and sight of children.

Pharmaceutical precautions

Do not store above 25°C. Do not freeze. Shake well before use.

This product does not contain an antimicrobial preservative.

Only dry, sterile needles and syringes should be used for administration and the septum should be swabbed before removing each dose.

After withdrawal of the first dose, use the product within 28 days.

Dispose of any unused product and empty containers in accordance with guidance from your local waste regulation authority.

Keep container in its outer carton.

Legal category


Packaging Quantities

Multidose vials of 80 ml.

Further information

Bioavailability studies indicate that a minimum duration of activity of 48 hours can be expected following a single injection.

Marketing authorisation number

Vm 01708/4233.

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