Ancef

Ancef,

a trademark for a semisynthetic cephalosporin antibiotic (cefazolin sodium).

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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: 250 mg, 500 mg, 1 g, 5 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.
• 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.

Route	Onset	Peak	Duration
I.V.	Rapid	End of infusion	6-12 hr
I.M.	Rapid	1-2 hr	6-12 hr

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

☞ 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.