Fortaz

Action

Interferes with bacterial cell-wall synthesis and division by binding to cell wall, causing cell to die. Active against gram-negative and gram-positive bacteria, with expanded activity against gram-negative bacteria. Exhibits minimal immunosuppressant activity.

Availability

Powder for injection: 500 mg, 1 g, 2 g, 6 g

Premixed containers: 1 g/50 ml, 2 g/50 ml

Indications and dosages

➣ Skin infections; bone and joint infections; urinary tract and gynecologic infections, including gonorrhea; respiratory tract infections; intraabdominal infections; septicemia
Adults and children ages 12 and older: For most infections, 500 mg to 2 g I.V. or I.M. q 8 to 12 hours. For pneumonia and skin infections, 0.5 to 1 g I.V. or I.M. q 8 to 12 hours. For bone and joint infections, 2 g I.V. or I.M. q 12 hours. For severe and life-threatening infections, 2 g I.V. q 8 hours. For complicated urinary tract infections (UTIs), 500 mg q 8 to 12 hours. For uncomplicated UTIs, 250 mg I.M. or I.V. q 12 hours.
Children ages 1 month to 12 years: 30 to 50 mg/kg I.V. q 8 hours
Neonates younger than 4 weeks: 30 mg/kg I.V. q 12 hours

Dosage adjustment

• Renal impairment

Off-label uses

• Febrile neutropenia

• Prophylaxis of perinatal infections

Contraindications

• Hypersensitivity to cephalosporins or penicillins

Precautions

Use cautiously in:

• renal impairment, hepatic disease, biliary obstruction, phenylketonuria

• history of GI disease

• elderly patients

• pregnant or breastfeeding patients

• children.

Administration

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

• Reconstitute powder for injection with sterile water, following manufacturer's directions for amount of diluent to use.

• For I.V. injection, dilute in sterile water as directed, and give single dose over 3 to 5 minutes. Inject into large vein; rotate injection sites.

• For intermittent I.V. infusion, dilute further with 100 ml of sterile water or another compatible fluid, such as normal saline solution or dextrose 5% in water. Infuse over 30 minutes.

• Don't dilute with sodium bicarbonate.

• For I.M. injection, reconstitute with sterile water, bacteriostatic water, or 0.5% or 1% lidocaine hydrochloride.

• When giving I.M., inject deep into large muscle mass.

Adverse reactions

CNS: headache, confusion, hemiparesis, lethargy, paresthesia, syncope, asterixis, neuromuscular excitability (with increased drug blood levels in renally impaired patients), seizures, encephalopathy

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, I.M. site pain, anaphylaxis, serum sickness

Interactions

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

Chloramphenicol: antagonism of ceftazidime's effects

Probenecid: decreased excretion and increased blood level of ceftazidime

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, eosinophils, gamma-glutamyltransferase, lactate dehydrogenase: increased levels

Hemoglobin, platelets, white blood cells: decreased values
Coombs' test, urinary 17-ketosteroids, nonenzyme-based urine glucose tests (such as Clinitest): false-positive results

Drug-herbs. Angelica, anise, arnica, asafetida, bogbean, boldo, celery, chamomile, clove, danshen, fenugreek, feverfew, garlic, ginger, ginkgo, ginseng, horse chestnut, horseradish, licorice, meadowsweet, onion, papain, passionflower, poplar, prickly ash, quassia, red clover, turmeric, wild carrot, wild lettuce, willow: increased risk of bleeding

Patient monitoring

Monitor for extreme confusion, tonic-clonic seizures, and mild hemiparesis when giving high doses.

• Assess CBC and kidney and liver function test results.

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

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

Patient teaching

• Instruct patient to report reduced urine output, persistent diarrhea, bruising, and bleeding.

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