cefazolin sodium


cefazolin sodium

Ancef

Pharmacologic class: First-generation cephalosporin

Therapeutic class: Anti-infective

Pregnancy risk category B

Action

Interferes with bacterial cell-wall synthesis, causing cell to rupture and die

Availability

Powder for injection: 500 mg, 1 g, 10 g, 20 g

Premixed containers: 500 mg/50 ml in dextrose 5% in water (D5W), 1 g/50 ml in D5W

Indications and dosages

Respiratory tract infections caused by group A beta-hemolytic streptococci, Klebsiella species, Haemophilus influenzae, and Staphylococcus aureus; skin infections caused by S. aureus and beta-hemolytic streptococci; biliary tract infections caused by Escherichia coli, Klebsiella species, Proteus mirabilis, and S. aureus; bone and joint infections caused by S. aureus; genital infections caused by E. coli, Klebsiella species, P. mirabilis, and strains of enterococci; septicemia caused by E. coli, Klebsiella species, P. mirabilis, S. aureus, and S. pneumoniae; endocarditis caused by S. aureus or beta-hemolytic streptococci

Adults: For mild infections, 250 to 500 mg q 8 hours I.V. or I.M. For moderate to severe infections, 500 to 1,000 mg I.V. or I.M. q 6 to 8 hours. For life-threatening infections, 1,000 to 1,500 mg I.M. or I.V. q 6 hours, to a maximum dosage of 6 g/day.

Children: For mild to moderate infections, 25 to 50 mg/kg/day I.V. or I.M. in divided doses t.i.d. or q.i.d. For severe infections, 100 mg/kg/day I.V. or I.M. in divided doses t.i.d. or q.i.d.

Acute uncomplicated urinary tract infections (UTIs) caused by E. coli, Klebsiella species, P. mirabilis, and strains of Enterococcus and Enterobacter species

Adults: 1 g I.V. or I.M. q 12 hours

Surgical prophylaxis

Adults: 1g I.V. or I.M. 30 to 60 minutes before surgery, then 0.5 to 1 g I.V. or I.M. q 6 to 8 hours for 24 hours. If surgery exceeds 2 hours, another 0.5- to 1-g dose I.M. or I.V. may be given intraoperatively.

Pneumococcal pneumonia

Adults: 500 mg I.M. or I.V. infusion q 12 hours

Dosage adjustment

• Renal impairment

• Elderly patients

Contraindications

• Hypersensitivity to cephalosporins or penicillins

Precautions

Use cautiously in:

• renal impairment, phenylketonuria

• history of GI disease (especially colitis)

• emaciated patients

• elderly patients

• pregnant or breastfeeding patients

• children.

Administration

• Obtain specimens for culture and sensitivity testing as needed before starting therapy.

• For intermittent I.V. infusion, administer in volume-control set or in separate, secondary I.V. container over 30 to 60 minutes.

• For direct I.V. injection, dilute reconstituted dose in 5 ml of sterile water for injection and administer slowly over 3 to 5 minutes.

• Don't mix premixed solution with other drugs.

See Don't use flexible container in series connections because of risk of air embolism.

• For I.M. use, reconstitute with sterile water for injection, bacteriostatic water, or normal saline solution for injection. Shake well until dissolved.

• Inject I.M. into large muscle mass.

Adverse reactions

CNS: headache, lethargy, confusion, hemiparesis, paresthesia, syncope, seizures

CV: hypotension, palpitations, chest pain, vasodilation

EENT: hearing loss

GI: nausea, vomiting, diarrhea, abdominal cramps, oral candidiasis, pseudomembranous colitis

GU: vaginal candidiasis, nephrotoxicity

Hematologic: lymphocytosis, eosinophilia, bleeding tendency, hemolytic anemia, hypoprothrombinemia, neutropenia, thrombocytopenia, agranulocytosis, bone marrow depression

Hepatic: hepatic failure, hepatomegaly

Musculoskeletal: arthralgia

Respiratory: dyspnea

Skin: urticaria, maculopapular or erythematous rash

Other: chills, fever, superinfection, anaphylaxis, serum sickness

Interactions

Drug-drug. Aminoglycosides, loop diuretics: increased risk of nephrotoxicity

Anticoagulants: increased anticoagulant effect

Chloramphenicol: antagonistic effect

Probenecid: decreased excretion and increased blood level of cefazolin

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, eosinophils, gamma-glutamyltransferase, lactate dehydrogenase: increased levels
Coombs' test, urinary 17-ketosteroids, nonenzyme-based urine glucose tests (such as Clinitest): false-positive results

Hemoglobin, platelets, white blood cells: decreased values

Drug-behaviors. Alcohol use: acute alcohol intolerance (disulfiram-like reaction) if alcohol is consumed within 72 hours of drug administration

Patient monitoring

See If patient is receiving high doses, monitor for extreme confusion, tonic-clonic seizures, and mild hemiparesis.

• Monitor CBC, prothrombin time, and kidney and liver function test results.

• Watch for signs and symptoms of superinfection and other serious adverse reactions.

• Be aware that cross-sensitivity to penicillins may occur.

Patient teaching

• Tell patient to report reduced urinary output, persistent diarrhea, bruising, or bleeding.

• Instruct patient to take drug exactly as prescribed and to complete full course of therapy even when he feels better.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.