Ampicillin and Sulbactam

UNASYN is indicated for the treatment of infections due to susceptible strains of the designated microorganisms in the conditions listed below. Skin and Skin Structure Infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli, Efficacy for this organism in this organ system was studied in fewer than 10 infections. Klebsiella spp. (including K. pneumoniae ), Proteus mirabilis, Bacteroides fragilis, Enterobacter spp., and Acinetobacter calcoaceticus. NOTE: For information on use in pediatric patients. Intra-Abdominal Infections caused by beta-lactamase producing strains of Escherichia coli, Klebsiella spp. (including K. pneumoniae ), Bacteroides spp. (including B. fragilis ), and Enterobacter spp. Gynecological Infections caused by beta-lactamase producing strains of Escherichia coli, and Bacteroides spp. (including B. fragilis ).

Ampicillin is similar to benzyl penicillin in its bactericidal action against susceptible organisms during the stage of active multiplication. It acts through the inhibition of cell wall mucopeptide biosynthesis. Ampicillin has a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria. (Ampicillin is, however, degraded by beta-lactamases and therefore the spectrum of activity does not normally include organisms which produce these enzymes). A wide range of beta-lactamases found in microorganisms resistant to penicillins and cephalosporins have been shown in biochemical studies with cell free bacterial systems to be irreversibly inhibited by sulbactam.

UNASYN may be administered by either the IV or the IM routes. For IV administration, the dose can be given by slow intravenous injection over at least 10–15 minutes or can also be delivered in greater dilutions with 50 mL–100 mL of a compatible diluent as an intravenous infusion over 15–30 minutes. UNASYN may be administered by deep intramuscular injection. The recommended adult dosage of UNASYN is 1.5 g (ampicillin 1 g and sulbactam 0.5 g) to 3 g (ampicillin 2 g and sulbactam 1 g) every six hours. This 1.5 g to 3 g range represents the total of ampicillin content plus the sulbactam content of UNASYN, and corresponds to a range of 1 g ampicillin and 0.5 g sulbactam to 2 g ampicillin and 1 g sulbactam. The total dose of sulbactam should not exceed 4 g per day.

The use of UNASYN is contraindicated in individuals with a history of serious hypersensitivity reactions (e.g., anaphylaxis or Stevens-Johnson syndrome) to ampicillin, sulbactam or to other beta-lactam antibacterial drugs (e.g., penicillins and cephalosporins). UNASYN is contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with UNASYN.

Hypersensitivity Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy. These reactions are more apt to occur in individuals with a history of penicillin hypersensitivity and/or hypersensitivity reactions to multiple allergens. There have been reports of individuals with a history of penicillin hypersensitivity who have experienced severe reactions when treated with cephalosporins. Before therapy with a penicillin, careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins, and other allergens. If an allergic reaction occurs, UNASYN should be discontinued and the appropriate therapy instituted. Hepatotoxicity Hepatic dysfunction, including hepatitis and cholestatic jaundice has been associated with the use of UNASYN.

Adult Patients UNASYN is generally well tolerated. The following adverse reactions have been reported in clinical trials. Local Adverse Reactions Pain at IM injection site – 16% Pain at IV injection site – 3% Thrombophlebitis – 3% Phlebitis – 1.2% Systemic Adverse Reactions The most frequently reported adverse reactions were diarrhea in 3% of the patients and rash in less than 2% of the patients. Additional systemic reactions reported in less than 1% of the patients were: itching, nausea, vomiting, candidiasis, fatigue, malaise, headache, chest pain, flatulence, abdominal distension, glossitis, urine retention, dysuria, edema, facial swelling, erythema, chills, tightness in throat, substernal pain, epistaxis and mucosal bleeding.

Probenecid decreases the renal tubular secretion of ampicillin and sulbactam. Concurrent use of probenecid with UNASYN may result in increased and prolonged blood levels of ampicillin and sulbactam. The concurrent administration of allopurinol and ampicillin increases substantially the incidence of rashes in patients receiving both drugs as compared to patients receiving ampicillin alone. It is not known whether this potentiation of ampicillin rashes is due to allopurinol or the hyperuricemia present in these patients. There are no data with UNASYN and allopurinol administered concurrently. UNASYN and aminoglycosides should not be reconstituted together due to the in vitro inactivation of aminoglycosides by the ampicillin component of UNASYN.

COMPATIBILITY, RECONSTITUTION AND STABILITY UNASYN sterile powder is to be stored at or below 30°C (86°F) prior to reconstitution.