ZOSYN is indicated for the treatment of patients with moderate to severe infections caused by piperacillin-resistant, piperacillin/tazobactam-susceptible, ?-lactamase producing strains of the designated microorganisms in the specified conditions listed below: Appendicitis (complicated by rupture or abscess) and peritonitis caused by piperacillin-resistant, ?-lactamase producing strains of Escherichia coli or the following members of the Bacteroides fragilis group: B.

fragilis, B.

ovatus, B.

thetaiotaomicron , or B.

vulgatus.

The individual members of this group were studied in less than 10 cases.

Uncomplicated and complicated skin and skin structure infections, including cellulitis, cutaneous abscesses and ischemic/diabetic foot infections caused by piperacillin-resistant, ?-lactamase producing strains of Staphylococcus aureus.

Postpartum endometritis or pelvic inflammatory disease caused by piperacillin-resistant, ?-lactamase producing strains of Escherichia coli.

Community-acquired pneumonia (moderate severity only) caused by piperacillin-resistant, ?-lactamase producing strains of Haemophilus influenzae.

Nosocomial pneumonia (moderate to severe) caused by piperacillin-resistant, ?-lactamase producing strains of Staphylococcus aureus and by piperacillin/tazobactam-susceptible Acinetobacter baumanii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa .

(Nosocomial pneumonia caused by P. aeruginosa should be treated in combination with an aminoglycoside.) (See DOSAGE AND ADMINISTRATION.) ZOSYN is indicated only for the specified conditions listed above.

Infections caused by piperacillin-susceptible organisms, for which piperacillin has been shown to be effective, are also amenable to ZOSYN treatment due to its piperacillin content. The tazobactam component of this combination product does not decrease the activity of the piperacillin component against piperacillin-susceptible organisms.

Therefore, the treatment of mixed infections caused by piperacillin-susceptible organisms and piperacillin-resistant, ?-lactamase producing organisms susceptible to ZOSYN should not require the addition of another antibiotic.

(See DOSAGE AND ADMINISTRATION.) ZOSYN is useful as presumptive therapy in the indicated conditions prior to the identification of causative organisms because of its broad spectrum of bactericidal activity against gram-positiveand gram-negative aerobic and anaerobic organisms.

Appropriate cultures should usually be performed before initiating antimicrobial treatment in order to isolate and identify the organisms causing infection and to determine their susceptibility to ZOSYN. Antimicrobial therapy should be adjusted, if appropriate, once the results of culture(s) and antimicrobial susceptibility testing are known.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Zosyn (piperacillin and tazobactam) injection and other antibacterial drugs, Zosyn (piperacillin and tazobactam) should be used only to treat or prevent 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.

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Infection -- Invasion of the host organism by microorganisms that can cause pathological conditions or diseases.

Appendicitis -- Acute inflammation of the APPENDIX. Acute appendicitis is classified as simple, gangrenous, or perforated.

Abscess -- Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection.

Peritonitis -- INFLAMMATION of the PERITONEUM lining the ABDOMINAL CAVITY as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the PERITONEAL CAVITY via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the ABDOMINAL CAVITY itself through RUPTURE or ABSCESS of intra-abdominal organs.

skin infection -- Skin diseases caused by bacteria, fungi, parasites, or viruses.

Cellulitis -- An acute, diffuse, and suppurative inflammation of loose connective tissue, particularly the deep subcutaneous tissues, and sometimes muscle, which is most commonly seen as a result of infection of a wound, ulcer, or other skin lesions.

Abscess of skin AND/OR subcutaneous tissue --

Pelvic Inflammatory Disease -- A spectrum of inflammation involving the female upper genital tract and the supporting tissues. It is usually caused by an ascending infection of organisms from the endocervix. Infection may be confined to the uterus (ENDOMETRITIS), the FALLOPIAN TUBES; (SALPINGITIS); the ovaries (OOPHORITIS), the supporting ligaments (PARAMETRITIS), or may involve several of the above uterine appendages. Such inflammation can lead to functional impairment and infertility.

Communicable Diseases -- broad class of diseases whose causative agents may be passed between individuals in many different ways.

ZOSYN is contraindicated in patients with a history of allergic reactions to any of the penicillins, cephalosporins, or?-lactamase inhibitors.

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Allergic Reaction --

SERIOUS AND OCCASIONALLY FATAL HYPERSENSITIVITY (ANAPHYLACTIC/ANAPHYLACTOID) REACTIONS (INCLUDING SHOCK) HAVE BEEN REPORTED IN PATIENTS RECEIVING THERAPY WITH PENICILLINS INCLUDING ZOSYN.

THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY OR A HISTORY OF SENSITIVITY 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 INITIATING THERAPY WITH ZOSYN, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS.

IF AN ALLERGIC REACTION OCCURS, ZOSYN SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED.

SERIOUS ANAPHYLACTIC/ANAPHYLACTOID REACTIONS (INCLUDING SHOCK) REQUIRE IMMEDIATE EMERGENCY TREATMENT WITH EPINEPHRINE.

OXYGEN, INTRAVENOUS STEROIDS, AND AIRWAY MANAGEMENT, INCLUDING INTUBATION, SHOULD ALSO BE ADMINISTERED AS INDICATED.Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including ZOSYN, and may range in severity from mild diarrhea to fatal colitis.

Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C.

difficile.C.

difficile produces toxins A and B which contribute to the development of CDAD.

Hypertoxin producing strains of C.

difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy.

CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued.

Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatmentof C.

difficile, and surgical evaluation should be instituted as clinically indicated.