Ampicillin with Sulbactam (Unisyn)


  • Antibiotic


  • Penicillin with beta-lactamase inhibitor

  • 500mg of sulbactam per 1 gram of ampicillin


  • Mild to moderate infections (i.e.; skin, intra-abdominal and gynecological infections)

  • susceptible strains of S. aureus, Klebsiella species, E. coli, H. influenzae, P. mirabilis, Bacteroides fragilis, Enterobacter species, Acinetobacter calcoaceticus


  • None


  • Pregnancy category B

  • Use with caution in patients with PCN or cephalosporin allergy (5-10% chance of cross-reactivity)

  • Dosage modifications are generally only required in patients with severe renal impairment

Adverse Reactions (Side Effects):

  • Hypersensitivity (rash not representing a true allergy)

  • Gastrointestinal: nausea, vomiting, diarrhea

  • Vaginitis


  • Administered IV or IM (powder for injection)

  • Adult:

    • 1.5-3 grams every 6 hours (not to exceed 4 grams per day of sulbactam component)

  • Child (>1 year old or < 40kg):

    • 300mg/kg/day in divided doses every 6 hours

  • Child (> 40kg):

    • adult dosing guidelines

Back to Medical Corps Pharmacy Page