Ampicillin and sulbactam injection for bacterial infections

Ampicillin and Sulbactam for Injection is a combination antibiotic consisting of ampicillin, a penicillin derivative, and sulbactam, a beta-lactamase inhibitor. This injectable medication is used to treat certain bacterial infections caused by susceptible bacteria. The addition of sulbactam extends ampicillin’s effectiveness against bacteria that produce beta-lactamase enzymes, which otherwise degrade ampicillin.

This injection is used to treat infections caused by susceptible bacteria in adults and pediatric patients, including:

• Skin and skin structure infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli, Klebsiella species (including K. pneumoniae), Proteus mirabilis, Bacteroides fragilis, Enterobacter species, and Acinetobacter calcoaceticus.
• Intra-abdominal infections caused by beta-lactamase producing Escherichia coli, Klebsiella species (including K. pneumoniae), Bacteroides species (including B. fragilis), and Enterobacter species.
• Gynecological infections caused by beta-lactamase producing Escherichia coli and Bacteroides species (including B. fragilis).

Mixed infections caused by organisms susceptible to ampicillin and those producing beta-lactamase susceptible to this combination may also be treated without additional antibiotics. Use should be guided by culture and susceptibility testing when possible.

Ampicillin sodium and Sulbactam sodium

Ampicillin works by killing bacteria during their active growth phase through inhibition of cell wall synthesis. Sulbactam does not have significant antibacterial activity alone but protects ampicillin by inhibiting beta-lactamase enzymes produced by resistant bacteria that would otherwise inactivate ampicillin. This combination broadens ampicillin’s antibacterial spectrum to include beta-lactamase producing organisms.

Together, they provide bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria, including strains producing certain beta-lactamases.

Administration: Ampicillin and Sulbactam for Injection is given by intravenous or intramuscular injection.

Adult dosing examples: 1.5 g (ampicillin 1 g and sulbactam 0.5 g) or 3 g (ampicillin 2 g and sulbactam 1 g) doses, often infused over 15 minutes.

Pharmacokinetics: Peak blood levels occur shortly after a 15-minute IV infusion. Half-life is approximately 1 hour in healthy individuals.

Renal impairment: Dosage frequency should be reduced in patients with impaired kidney function according to standard ampicillin dosing adjustments.

Pediatric patients: Pharmacokinetics are similar to adults. Doses are weight-based, often 50 to 75 mg/kg infused over 15 minutes.

• History of serious hypersensitivity reactions (e.g., anaphylaxis, Stevens-Johnson syndrome) to ampicillin, sulbactam, or other beta-lactam antibiotics (penicillins, cephalosporins).
• Previous cholestatic jaundice or hepatic dysfunction associated with this drug.

Hypersensitivity: Serious and sometimes fatal allergic reactions, including anaphylaxis and Stevens-Johnson syndrome, have been reported. Patients with a history of penicillin or beta-lactam allergies are at higher risk. Discontinue immediately if an allergic reaction occurs.

Hepatotoxicity: Hepatitis and cholestatic jaundice associated with this medication have occurred, sometimes fatal. Monitor liver function, especially in patients with pre-existing liver impairment.

Severe skin reactions: Conditions such as toxic epidermal necrolysis, Stevens-Johnson syndrome, and drug reaction with eosinophilia and systemic symptoms (DRESS) may occur. Discontinue if rash progresses.

Clostridioides difficile-associated diarrhea (CDAD): Use can lead to overgrowth of C. difficile causing severe diarrhea and colitis, potentially fatal. Consider CDAD in any patient with diarrhea during or after therapy. Discontinue non-C. difficile antibacterial drugs if CDAD is confirmed and manage accordingly.

Common: Rash and mild gastrointestinal upset may occur.

Serious: Anaphylaxis, severe skin reactions (TEN, SJS, DRESS), hepatotoxicity (including fatal cholestatic jaundice), and Clostridioides difficile-associated diarrhea are serious adverse effects reported with this medication.

• Probenecid may increase and prolong blood levels of ampicillin and sulbactam by decreasing renal tubular secretion.
• Concurrent use of allopurinol with ampicillin increases rash incidence; data for the combination injection are not available.
• Ampicillin and sulbactam should not be mixed with aminoglycoside antibiotics in the same solution due to inactivation of the aminoglycoside.

Following administration to pregnant women, transient decreases in plasma conjugated estriol levels have been observed. Data do not establish clear safety or risks during pregnancy or breastfeeding; use only if clearly indicated and under medical supervision.

Symptoms of overdose are consistent with penicillin toxicity and may include renal impairment and neurotoxicity. Management is supportive and symptomatic.