To reduce the development of drug-resistant bacteria and maintain the effectiveness of AZACTAM® (aztreonam for injection, USP) and other antibacterial drugs, AZACTAM 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.AZACTAM (aztreonam for injection, USP) is indicated for the treatment of the following infections caused by susceptible gram-negative microorganisms:Urinary Tract Infections (complicated and uncomplicated), including pyelonephritis and cystitis (initial and recurrent) caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella oxytoca*, Citrobacter species* and Serratia marcescens*.Lower Respiratory Tract Infections, including pneumonia and bronchitis caused by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae, Proteus mirabilis, Enterobacter species and Serratia marcescens*.Septicemia caused by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis*, Serratia marcescens* and Enterobacter species.Skin and Skin-Structure Infections, including those associated with postoperative wounds, ulcers and burns caused by Escherichia coli, Proteus mirabilis, Serratia marcescens, Enterobacter species, Pseudomonas aeruginosa, Klebsiella pneumoniae and Citrobacter species*.Intra-abdominal Infections, including peritonitis caused by Escherichia coli, Klebsiella species including K. pneumoniae, Enterobacter species including E.

cloacae*, Pseudomonas aeruginosa, Citrobacter species* including C.

freundii* and Serratia species* including S.

marcescens*.Gynecologic Infections, including endometritis and pelvic cellulitis caused by Escherichia coli, Klebsiella pneumoniae*, Enterobacter species* including E.

cloacae* and Proteus mirabilis*.AZACTAM is indicated for adjunctive therapy to surgery in the management of infections caused by susceptible organisms, including abscesses, infections complicating hollow viscus perforations, cutaneous infections and infections of serous surfaces.

AZACTAM is effective against most of the commonly encountered gram-negative aerobic pathogens seen in general surgery.*Efficacy for this organism in this organ system was studied in fewer than 10 infections.

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

Urinary tract infection -- Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.

Pyelonephritis -- Inflammation of the KIDNEY involving the renal parenchyma (the NEPHRONS); KIDNEY PELVIS; and KIDNEY CALICES. It is characterized by ABDOMINAL PAIN; FEVER; NAUSEA; VOMITING; and occasionally DIARRHEA.

Cystitis -- Inflammation of the URINARY BLADDER, either from bacterial or non-bacterial causes. Cystitis is usually associated with painful urination (dysuria), increased frequency, urgency, and suprapubic pain.

Lower respiratory tract infection --

Pneumonia -- Inflammation of any part, segment or lobe, of the lung parenchyma.

Acute bronchitis -- sudden inflammation of the tracheobronchial tree, which comprises the trachea, or windpipe, and the bronchi; typically associated with a viral upper respiratory tract infection, such as the common cold, and is usually mild; in patients with chronic lung or heart disease, acute bronchitis is more severe, and can become chronic and progress to pneumonia.

Bronchitis -- Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.

Septicemia due to serratia --

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

Ulcer -- A lesion on the surface of the skin or a mucous surface, produced by the sloughing of inflammatory necrotic tissue.

Abdominal 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.

Endometritis -- Inflammation of the ENDOMETRIUM, usually caused by intrauterine infections. Endometritis is the most common cause of postpartum fever.

Parametritis -- Inflammation of the parametrium, the connective tissue of the pelvic floor, extending from the subserous coat of the uterus laterally between the layers of the BROAD LIGAMENT.

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

This preparation is contraindicated in patients with known hypersensitivity to aztreonam or any other component in the formulation.

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Hypersensitivity -- Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.

Both animal and human data suggest that AZACTAM is rarely cross-reactive with other beta-lactam antibiotics and weakly immunogenic.

Treatment with aztreonam can result in hypersensitivity reactions in patients with or without prior exposure.

(See CONTRAINDICATIONS.)Careful inquiry should be made to determine whether the patient has any history of hypersensitivity reactions to any allergens.While cross-reactivity of aztreonam with other beta-lactam antibiotics is rare, this drug should be administered with caution to any patient with a history of hypersensitivity to beta-lactams (eg, penicillins, cephalosporins, and/or carbapenems).

Treatment with aztreonam can result in hypersensitivity reactions in patients with or without prior exposure to aztreonam.

If an allergic reaction to aztreonam occurs, discontinue the drug and institute supportive treatment as appropriate (eg, maintenance of ventilation, pressor amines, antihistamines, corticosteroids).

Serious hypersensitivity reactions may require epinephrine and other emergency measures.

(See ADVERSE REACTIONS.)Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including AZACTAM, 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 treatment of C.

difficile, and surgical evaluation should be instituted as clinically indicated.Rare cases of toxic epidermal necrolysis have been reported in association with aztreonam in patients undergoing bone marrow transplant with multiple risk factors including sepsis, radiation therapy and other concomitantly administered drugs associated with toxic epidermal necrolysis.