UNASYN

INDICATIONS AND USAGE 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 (see PRECAUTIONS–Pediatric Use and CLINICAL STUDIES sections). 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 ). While UNASYN is indicated only for the conditions listed above, infections caused by ampicillin-susceptible organisms are also amenable to treatment with UNASYN due to its ampicillin content. Therefore, mixed infections caused by ampicillin-susceptible organisms and beta-lactamase producing organisms susceptible to UNASYN should not require the addition of another antibacterial. Appropriate culture and susceptibility tests should be performed before treatment in order to isolate and identify the organisms causing infection and to determine their susceptibility to UNASYN. Therapy may be instituted prior to obtaining the results from bacteriological and susceptibility studies when there is reason to believe the infection may involve any of the beta-lactamase producing organisms listed above in the indicated organ systems. Once the results are known, therapy should be adjusted if appropriate. To reduce the development of drug-resistant bacteria and maintain effectiveness of UNASYN and other antibacterial drugs, UNASYN should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

DOSAGE AND ADMINISTRATION 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. (see DIRECTIONS FOR USE-Preparation for Intravenous Use section). UNASYN may be administered by deep intramuscular injection (see DIRECTIONS FOR USE-Preparation for Intramuscular Injection section). 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. Pediatric Patients 1 Year of Age or Older The recommended daily dose of UNASYN in pediatric patients is 300 mg per kg of body weight administered via intravenous infusion in equally divided doses every 6 hours. This 300 mg/kg/day dosage represents the total ampicillin content plus the sulbactam content of UNASYN, and corresponds to 200 mg ampicillin and 100 mg sulbactam per kg per day. The safety and efficacy of UNASYN administered via intramuscular injection in pediatric patients have not been established. Pediatric patients weighing 40 kg or more should be dosed according to adult recommendations, and the total dose of sulbactam should not exceed 4 g per day. The course of intravenous therapy should not routinely exceed 14 days. In clinical trials, most pediatric patients received a course of oral antimicrobials following initial treatment with intravenous UNASYN (see CLINICAL STUDIES section). Impaired Renal Function In patients with impairment of renal function the elimination kinetics of ampicillin and sulbactam are similarly affected, hence the ratio of one to the other will remain constant whatever the renal function. The dose of UNASYN in such patients should be administered less frequently in accordance with the usual practice for ampicillin and according to the following recommendations: TABLE 3 UNASYN Dosage Guide for Patients with Renal Impairment Creatinine Clearance (mL/min/1.73m 2 ) Ampicillin and Sulbactam Half-Life (Hours) Recommended UNASYN Dosage ≥30 1 1.5 g to 3 g every 6 to 8 hours 15–29 5 1.5 g to 3 g every 12 hours 5–14 9 1.5 g to 3 g every 24 hours When only serum creatinine is available, the following formula (based on sex, weight, and age of the patient) may be used to convert this value into creatinine clearance. The serum creatinine should represent a steady state of renal function. Males Weight (kg) x (140 – age) 72 x serum creatinine Females 0.85 x above value

CONTRAINDICATIONS 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.

ADVERSE REACTIONS 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. Pediatric Patients Available safety data for pediatric patients treated with UNASYN demonstrate a similar adverse events profile to those observed in adult patients. Additionally, atypical lymphocytosis has been observed in one pediatric patient receiving UNASYN. Adverse Laboratory Changes Adverse laboratory changes without regard to drug relationship that were reported during clinical trials were: Hepatic: Increased AST (SGOT), ALT (SGPT), alkaline phosphatase, and LDH. Hematologic: Decreased hemoglobin, hematocrit, RBC, WBC, neutrophils, lymphocytes, platelets and increased lymphocytes, monocytes, basophils, eosinophils, and platelets. Blood Chemistry: Decreased serum albumin and total proteins. Renal: Increased BUN and creatinine. Urinalysis: Presence of RBC's and hyaline casts in urine. Post-marketing Experience In addition to adverse reactions reported from clinical trials, the following have been identified during post-marketing use of ampicillin sodium and sulbactam sodium or other products containing ampicillin. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency, or potential causal connection to ampicillin sodium and sulbactam sodium. Infections and Infestations: Clostridioides difficile -associated diarrhea (see WARNINGS section). Blood and Lymphatic System Disorders: Hemolytic anemia, thrombocytopenic purpura, and agranulocytosis have been reported. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena. Some individuals have developed positive direct Coombs Tests during treatment with UNASYN, as with other beta-lactam antibacterials. Gastrointestinal Disorders: Abdominal pain, cholestatic hepatitis, cholestasis, hyperbilirubinemia, jaundice, abnormal hepatic function, melena, gastritis, stomatitis, dyspepsia, and black "hairy" tongue (see CONTRAINDICATIONS AND WARNINGS sections). General Disorders and Administration Site Conditions: Injection site reaction Immune System Disorders: Serious and fatal hypersensitivity (anaphylactic) reactions (see WARNINGS section), Acute myocardial ischemia with or without myocardial infarction may occur as part of an allergic reaction. Metabolism and Nutrition Disorders: Hypokalemia Nervous System Disorders: Convulsion and dizziness Renal and Urinary Disorders: Tubulointerstitial nephritis Musculoskeletal and Connective Tissue Disorders: Arthralgia Respiratory, Thoracic and Mediastinal Disorders: Dyspnea Skin and Subcutaneous Tissue Disorders: Toxic epidermal necrolysis, Stevens-Johnson syndrome, drug reaction with eosinophilia and systemic symptoms (DRESS), angioedema, Acute generalized exanthematous pustulosis (AGEP), erythema multiforme, exfoliative dermatitis, urticaria (see CONTRAINDICATIONS and WARNINGS sections), and linear IgA bullous dermatosis.

Drug Interactions 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.

DESCRIPTION UNASYN (ampicillin and sulbactam) for injection, USP is a sterile antibacterial fixed-combination drug product consisting of the semisynthetic antibacterial ampicillin sodium and the beta-lactamase inhibitor sulbactam sodium for intravenous and intramuscular administration. Ampicillin sodium is derived from the penicillin nucleus, 6-aminopenicillanic acid. Chemically, it is monosodium (2S, 5R, 6R)-6-[(R)-2-amino-2-phenylacetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate and has a molecular weight of 371.39. Its chemical formula is C 16 H 18 N 3 NaO 4 S. The structural formula is: Sulbactam sodium is a derivative of the basic penicillin nucleus. Chemically, sulbactam sodium is sodium penicillinate sulfone; sodium (2S, 5R)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0]heptane-2-carboxylate 4,4-dioxide. Its chemical formula is C 8 H 10 NNaO 5 S with a molecular weight of 255.22. The structural formula is: UNASYN is available as a white to off-white dry powder for reconstitution. UNASYN dry powder is freely soluble in aqueous diluents to yield pale yellow to yellow solutions. The pH of the solutions is between 8.0 and 10.0. Dilute solutions (up to 30 mg ampicillin and 15 mg sulbactam per mL) are essentially colorless to pale yellow. The pH of dilute solutions remains the same. UNASYN pharmacy bulk package is a vial containing a sterile preparation for parenteral use. The Pharmacy Bulk Package is for use in a pharmacy admixture setting; it provides many single doses of UNASYN for addition to suitable parenteral fluids in the preparation of admixtures for intravenous infusion (see DIRECTIONS FOR USE–Directions for Proper Use of Pharmacy Bulk Package section). Each 15 g vial contains ampicillin 10 g and sulbactam 5 g (equivalent to 10.627 g ampicillin sodium and 5.470 g sulbactam sodium). Each 1.5 g of UNASYN contains approximately 115 mg of sodium. Chemical Structure Chemical Structure

OVERDOSAGE Neurological adverse reactions, including convulsions, may occur with the attainment of high CSF levels of beta-lactams. Ampicillin may be removed from circulation by hemodialysis. The molecular weight, degree of protein binding and pharmacokinetics profile of sulbactam suggest that this compound may also be removed by hemodialysis.

HOW SUPPLIED UNASYN (ampicillin and sulbactam) for injection, USP, a sterile off-white dry powder, is available in Pharmacy Bulk Package: Vials containing 15 g (ampicillin 10 g and sulbactam 5 g) NDC 0049-0024-28 (contains one of NDC 0049-0024-28). Vials containing 15 g (ampicillin 10 g and sulbactam 5 g) NDC 0049-1515-02 (contains one of NDC 0049-1515-01). UNASYN sterile powder is to be stored at or below 30°C (86°F) prior to reconstitution. OTHER SIZE PACKAGES AVAILABLE UNASYN is also supplied in glass vial in the following package sizes: Carton of 10 single-dose vials containing 1.5 g (ampicillin 1 g and sulbactam 0.5 g) NDC 0049-0013-83 (10 of NDC 0049-0013-81). Carton of 10 single-dose vials containing 1.5 g (ampicillin 1 g and sulbactam 0.5 g) NDC 0049-0710-10 (10 of NDC 0049-0710-01). Carton of 10 single-dose vials containing 3 g (ampicillin 2 g and sulbactam 1 g) NDC 0049-0014-83 (10 of NDC 0049-0014-81). Carton of 10 single-dose vials containing 3 g (ampicillin 2 g and sulbactam 1 g) NDC 0049-3003-10 (10 of NDC 0049-3003-01). To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or http://www.fda.gov/ for voluntary reporting of adverse reactions. This product's labeling may have been updated. For the most recent prescribing information, please visit www.pfizer.com . Rx only LAB-0018-26.0 Revised November 2025 Logo