Combination of
Ampicillin Moderate-spectrum penicillin
Flucloxacillin Antistaphylococcal penicillin
Clinical data
Routes of
Oral, intravenous
ATC code
CAS Number

Ampicillin/flucloxacillin (INNs) or co-fluampicil (BAN) is a combination drug of the two β-lactam antibiotics Ampicillin and flucloxacillin, sold under the tradenames Magnapen[1] and Infectrin.


Ampicillin is a moderate-spectrum penicillin antibiotic with good cover against group A streptococcal infection, whilst flucloxacillin is a narrow-spectrum antibiotic with cover against Staphylococcus aureus. The combination covers the two most likely bacteria in cellulitis infections in the arm or leg.


Capsules contain 250 mg of each component, the syrup 125/125 mg per spoon, and the powder for reconstruction for intravenous injection 250/250 mg.

Side effects and contraindications

Side effects are the same as per the individual components, with stomach or bowel upset from the flucloxacillin being the most common. Both parts are members of the penicillin family of antibiotics, so should not be taken by patients allergic to penicillin. See flucloxacillin for additional contraindications.


  1. Lloyd-Williams, J; Robinson, AT (1980). "The treatment of infections in general practice with magnapen: a multicentre trial". The Journal of international medical research. 8 (6): 417–23. PMID 7439518.