ampicillin sulbactam (Unasyn)

Introduction

Tradename: Unasyn.

Indications

• treatment of bacterial infections caused by susceptible bacteria
  • skin or soft tissue infection
    • diabetic foot infection
  • infectious arthritis, osteomyelitis
  • treatment of intra-abdominal infections
    • diverticulitis
    • abdominal abscess
    • cholangitis
  • urogenital infection
    • pelvic inflammatory disease
  • acute otitis media
  • lower respiratory tract infection
    • pneumonia
  • meningitis
  • mammal bite
• broad-spectrum antibiotic coverage, especially when Enterococcus or anaerobes are suspected
• empiric treatment of fever of unknown origin

Contraindications

pregnancy-category B

safety in lactation ?

Dosage

1.5-3 g IV every 6 hours

Dosage adjustment in renal failure

creatinine clearance dosage > 50-90 mL/min every 6 hours 10-50 mL/min every 8-12 hours < 10 mL/min* every 24 hours

* dose after hemodialysis

Pharmacokinetics

• elimination: kidney
• low CSF penetration in the absence of meningeal inflammation (see ampicillin)
• 1/2 life 1-2 hours, increased with renal failure
• removed by hemodialysis

Antimicrobial activity

Gram positive

• Streptococcus
  • Streptococcus group A
  • Streptococcus group B
  • Streptococcus group C
  • Streptococcus group G
  • Streptococcus pneumonia
  • Streptococcus viridans, milleri
• Enterococcus faecalis
• Enterococcus faecium
• Staphylococcus aureus (MSSA)
• Staphylococcus epidermidis
• Listeria monocytogenes

Gram negative

• Neisseria gonorrhoeae
• Neisseria meningitidis
• Moraxella catarrhalis
• Haemophilus influenzae
• Escherichia coli
• Klebsiella species
• Salmonella species
• Shigella species
• Proteus mirabilis
• Proteus vulgaris
• Providencia species
• Morganella species
• Aeromonas species
• Acinetobacter species
• Yersinia enterocolitica (+/-)
• Pasteurella multocida
• Haemophilus ducreyi

Anaerobes

• Actinomyces
• Bacteroides fragilis
• Bacteroides melaninogenicus
• Clostridium difficile
• Clostridium species
• Peptostreptococcus species

Adverse effects

• common (> 10%)
  • pain at injection site (16% IM, 3% IV)
• less common (1-10%)
  • diarrhea
  • skin rash, urticarial rash in infectious mononucleosis
• uncommon (< 1%)
  • chest pain, fatigue, malaise, headache, chills, itching, nausea/vomiting, enterocolitis, pseudomembranous colitis, hairy tongue, dysuria, leukopenia, thrombocytopenia, anemia, elevated serum transaminases, thrombophlebitis, increased BUN & creatinine, candidiasis/superinfection, hypersensitivity reactions
• other
  • blood dyscrasias (rare)
  • seizures (rare)
  • cholestatic hepatitis Mecahnism of action:
• ampicillin is an inhibitor of bacterial cell wall synthesis
• sulbactam is an inhibitor of plasmid-mediated beta-lactamase

More general terms

• beta-lactam/beta-lactamase inhibitor

Additional terms

• beta lactamase

Components

• ampicillin (Principen, Omnipen, Amcill, Polycillin, Polycillin-N, D-cillin, J-cillin, Marcillin, Rancillin Totacillin-N)
• sulbactam

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=119561
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=465585
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=461572