Ceftazidime

Class: Third Generation Cephalosporins
Chemical Name: [6R-[6α,7β(Z)]]-1-[[7-[[(2-Amino-4-thiazolyl) [(1 - carboxy - 1 - methylethoxy)imino]acetyl]amino] - 2 - carboxy - 8 - oxo - 5 - thia - 1 - azabicyclo[4.2.0]oct - 2 - en - 3 - yl]methyl] pyridinium hydroxide, inner salt, pentahydrate
CAS Number: 78436-06-2
Brands: Fortaz

Introduction

Antibacterial; β-lactam antibiotic; third generation cephalosporin.^{1 3 7 10 45 50 53 54 56 147 150 203 217}

Uses for Ceftazidime

Bone and Joint Infections

Treatment of bone and joint infections caused by susceptible Staphylococcus aureus (oxacillin-susceptible strains only) Klebsiella, or Pseudomonas aeruginosa.^{1 104 118 136 298}

Intra-abdominal and Gynecologic Infections

Treatment of gynecologic infections (including endometritis, pelvic cellulitis, other infections of the female genital tract) caused by susceptible Escherichia coli.¹

Treatment of intra-abdominal infections (including peritonitis) caused by susceptible S. aureus (oxacillin-susceptible strains only), E. coli, or Klebsiella.¹

Treatment of polymicrobial intra-abdominal infections caused by susceptible aerobic and anaerobic bacteria and Bacteroides.^{1 136 137} Consider that many strains of B. fragilis are resistant; generally should not be used alone in serious intra-abdominal infections when this organism may be involved.^{1 a}

Meningitis and Other CNS Infections

Treatment of meningitis caused by susceptible H. influenzae, Neisseria meningitidis, Ps. aeruginosa, or Streptococcus pneumoniae in adults or children.^{1 46 47 50 137 254}

Ceftazidime in conjunction with an aminoglycoside considered a regimen of choice for treatment of meningitis caused by susceptible P. aeruginosa^{13 14 112 147 218 337 354} or susceptible Enterobacteriaceae† (e.g., E. coli, P. mirabilis, Enterobacter, S. marcescens).^{46 47 218 222 223 224 335}

Cefotaxime or ceftriaxone generally preferred when a third generation cephalosporin is indicated for treatment of meningitis caused by H. influenzae, N. meningitidis, or S. pneumoniae.^{47 150 216 218 335 336 337 338}

Respiratory Tract Infections

Treatment of respiratory tract infections (including pneumonia) caused by susceptible S. aureus (oxacillin-susceptible [methicillin-susceptible] strains only), S. pneumoniae, Citrobacter, Enterobacter, E. coli, Klebsiella, Proteus mirabilis, Pseudomonas (including Ps. aeruginosa), or Serratia.^{1 103 108 117 118 119 120 137 143 144 146 147 148}

For treatment of community-acquired pneumonia (CAP) caused by Ps. aeruginosa, ATS and IDSA recommend a combination regimen that includes an antipseudomonal β-lactam (cefepime, ceftazidime, aztreonam, imipenem, meropenem, piperacillin, ticarcillin) given in conjunction with ciprofloxacin, levofloxacin, or an aminoglycoside.²²⁷

Septicemia

Treatment of septicemia caused by susceptible S. aureus (oxacillin-susceptible strains only), S. pneumoniae, Haemophilus influenzae, E. coli, Klebsiella, Ps. aeruginosa, or Serratia.^{1 115 118 119 120 146}

Skin and Skin Structure Infections

Treatment of skin and skin structure infections caused by susceptible S. aureus (oxacillin-susceptible strains only), S. pyogenes (group A β-hemolytic streptococci), Enterobacter, E. coli, Klebsiella, Proteus (including P. mirabilis), Ps. aeruginosa, or Serratia.^{1 115 118 119 120 136 146}

Urinary Tract Infections (UTIs)

Treatment of uncomplicated and complicated UTIs caused by susceptible Enterobacter, E. coli, Klebsiella, Proteus (including P. mirabilis), Ps. aeruginosa, or Serratia.^{1 106 113 115 118 119 137 141 145 153}

Burkholderia Infections

Treatment of septicemia or pulmonary infections caused by Burkholderia cepacia† (formerly Ps. cepacia);^{147 208 218 345} alone or in conjunction with an aminoglycoside.^{147 208 218 345} Co-trimoxazole considered drug of choice; ceftazidime, chloramphenicol, or imipenem are alternatives.²¹⁸

Treatment of severe melioidosis† caused by B. pseudomallei (formerly Ps. pseudomallei).^{218 264 266 267 276 277 346 355 356 357 358} Localized or mild disease may be effectively treated with a prolonged regimen of oral anti-infectives (e.g., co-trimoxazole with or without doxycycline).³⁵⁶ Severe illness usually treated with an initial parenteral regimen of ceftazidime, imipenem, or meropenem (some clinicians recommend that co-trimoxazole also be included, especially if the patient is septicemic) followed by prolonged maintenance with oral anti-infectives (e.g., co-trimoxazole with or without doxycycline).^{261 355 356 357 358} B. pseudomallei is difficult to eradicate (relapse of melioidosis is common).^{264 266 276 346 355} a

Otitis Externa

Treatment of malignant otitis externa† caused by Ps. aeruginosa.^{352 353}

Acute bacterial otitis externa localized in the external auditory canal may be effectively treated using topical anti-infectives (e.g., otic preparations of ciprofloxacin or ofloxacin), but malignant otitis externa is an invasive, potentially life-threatening infection (especially in immunocompromised patients such as those with diabetes mellitus or HIV infection) and requires prompt diagnosis and long-term treatment with parenteral anti-infectives (e.g., ceftazidime and/or ciprofloxacin).^{352 353}

Pseudomonas aeruginosa Infections

Generally considered a drug of choice for treatment of infections caused by Ps. aeruginosa,^{50 57 147 186 198} including acute exacerbations of bronchopulmonary Ps. aeruginosa infections in children and adults with cystic fibrosis.^{28 119 125 126 128 129 130 132 134 147 150 154 208 246 313 332 348}

In severe infections, especially in immunocompromised patients, concomitant use of ceftazidime and an aminoglycoside (e.g., amikacin, gentamicin, tobramycin) is recommended.²¹⁸ Consider that ceftazidime-resistant strains of Ps. aeruginosa can emerge during therapy and superinfection with resistant strains has occurred.^{50 111 115 147}

Anti-infective therapy in patients with cystic fibrosis may result in clinical improvement and Ps. aeruginosa may be temporarily cleared from the sputum, but a bacteriologic cure is rarely obtained and should not be expected.^{28 119 125 126 132 149 150 208 246 313}

Vibrio Infections

Treatment of infections caused by Vibrio vulnificus†.^{219 256}

Optimum anti-infective therapy has not been identified; a tetracycline or third generation cephalosporin (e.g., cefotaxime, ceftazidime) is recommended.^{218 219 256} Because the case fatality rate associated with V. vulnificus is high, initiate anti-infective therapy promptly if indicated.^{256 262}

Empiric Therapy in Febrile Neutropenic Patients

Empiric treatment of presumed bacterial infections in febrile neutropenic adults or children†.^{122 123 124 138 139 140 212 228 247 248 249 275 279 280 286 287 288 289 290 291 292 294 295 347 349} Has been used alone or in conjunction with an aminoglycoside (e.g., amikacin, gentamicin, tobramycin).^{124 138 139 140 212 228 247 248 249 275 290 292 295}

Consider that gram-positive bacteria have become a predominant pathogen in febrile neutropenic patients and that ceftazidime is less active against gram-positives than many other cephalosporins and β-lactam antibiotics.^{122 124 212 222 229 281 282 284} An anti-infective active against staphylococci (e.g., vancomycin) probably should be used concomitantly if ceftazidime is used for empiric therapy.^{122 124 132 138 139 140 212 222 229 247}

Consult published protocols for the treatment of infections in febrile neutropenic patients for specific recommendations regarding selection of the initial empiric regimen, when to change the initial regimen, possible subsequent regimens, and duration of therapy in these patients.²⁸² Consultation with an infectious disease expert knowledgeable about infections in immunocompromised patients also is advised.^{281 282}

Perioperative Prophylaxis

Has been used for perioperative prophylaxis† in patients undergoing vaginal hysterectomy,¹⁵¹ intra-abdominal surgery,¹⁶⁷ or transurethral resection of the prostate.¹⁴²

Other cephalosporins or cephamycins (cefazolin, cefotetan, cefoxitin) are preferred drugs for perioperative prophylaxis.²²⁰ Ceftazidime and other third generation cephalosporins usually not used for perioperative prophylaxis since they are expensive, some are less active against staphylococci than cefazolin, they have a spectrum of activity wider than necessary for organisms encountered in elective surgery, and their use for prophylaxis promotes emergence of resistant organisms.^{147 220 221 222}

Ceftazidime Dosage and Administration

Administration

Administer by intermittent IV injection or infusion or by deep IM injection.^{1 217} Also has been administered by continuous IV infusion†.^{299 300 301 302 310 332 348}

Has been administered intraperitoneally in dialysis solutions.^{1 27 217} Should not be administered by intra-arterial injection since arteriospasm and necrosis can occur.^{1 217}

IV route preferred for treatment of septicemia, meningitis, peritonitis, or other severe or life-threatening infections and in patients with lowered resistance resulting from malnutrition, trauma, surgery, diabetes, heart failure, or malignancy, particularly if shock is present or impending.^{1 217}

The commercially available frozen ceftazidime injection in dextrose should be used only for IV infusion.¹

IV Injection

Reconstitution

For intermittent IV injection, reconstitute vials containing 500 mg, 1 g, or 2 g with 5.3 mL, 10, or 10 mL, respectively, of sterile water for injection to provide solutions containing approximately 100, 100, or 170mg/mL, respectively.^{1 217}

Shake vial after adding the diluent;^{1 217} carbon dioxide is released as drug dissolves and the solution will become clear within 1–2 minutes.^{1 217} When withdrawing a dose from reconstituted vials, consider that the solution may contain some carbon dioxide bubbles which should be expelled from the syringe before injection.^{1 217}

Rate of Administration

Inject appropriate dose of reconstituted solution into a vein over a period of 3–5 minutes or slowly into the tubing of a compatible IV solution.^{1 217}

IV Infusion

Reconstitution and Dilution

Reconstitute vials of containing 1 or 2 g of ceftazidime with 100 mL of sterile water for injection or compatible IV solution.^{1 217} Shake the vial after adding the diluent;^{1 217} carbon dioxide is released as the drug dissolves and the solution will become clear within 1–2 minutes.^{1 217} The appropriate dose of the drug should then be added to a compatible IV solution.^{1 217}

Reconsitute pharmacy bulk packages according to the manufacturer's directions and then further dilute in a compatible IV infusion solution prior to administration.^{1 233}

ADD-Vantage vials labeled as containing 1 or 2 g of ceftazidime should be reconstituted according to the manufacturer’s directions.^{1 217}

Thaw the commercially available injection (frozen) at room temperature or in a refrigerator; do not force thaw by immersion in a water bath or by exposure to microwave radiation.¹ A precipitate may have formed in the frozen injection, but should dissolve with little or no agitation after reaching room temperature.¹ Discard thawed injection if an insoluble precipitate is present or if container seals or outlet ports are not intact.^{1 231 232} The injection should not be used in series connections with other plastic containers, since such use could result in air embolism from residual air being drawn from the primary container before administration of fluid from the secondary container is complete.^{1 231 232}

Rate of Administration

Intermittent IV infusions generally have been infused over 15–30 minutes in adults,^{8 102 104 105 115 116 118 119 133 137 139 144} neonates,³⁴ and children.^{108 157}

If a Y-type administration set is used, the other solution flowing through the tubing should be discontinued while ceftazidime is being infused.^{1 217 262}

IM Injection

IM injections should be made deeply into a large muscle mass, such as the upper outer quadrant of the gluteus maximus or lateral part of the thigh.^{1 217}

Reconstitution

IM injections are prepared by adding 1.5 or 3 mL of sterile or bacteriostatic water for injection or 0.5 or 1% lidocaine hydrochloride injection to vials containing 500 mg or 1 g of ceftazidime, respectively, to provide solutions containing approximately 280 mg/mL.¹

Shake the vial after adding the diluent;^{1 217} carbon dioxide is released as the drug dissolves and the solution will become clear within 1–2 minutes.^{1 217} When withdrawing a dose from reconstituted vials, consider that the solution may contain some carbon dioxide bubbles which should be expelled from the syringe before injection.^{1 217}

Intraperitoneal Instillation

Reconstitute with sterile water for injection as for IV infusion²²¹ and then further dilute in a compatible peritoneal dialysis solution to provide a solution containing 250 mg of ceftazidime in each 2 L of dialysis solution.^{1 217}

Dosage

Available as ceftazidime pentahydrate and as ceftazidime sodium; dosage expressed as anhydrous ceftazidime.^{1 3 217}

Pediatric Patients

General Pediatric Dosage in Neonates

IV

Neonates ≤4 weeks of age: manufacturer recommends 30 mg/kg every 12 hours.^{1 217}

Neonates <1 week of age: AAP recommends 50 mg/kg every 12 hours in those weighing ≤2 kg and 50 mg/kg every 8 or 12 hours in those weighing >2 kg.²⁶¹

Neonates 1–4 weeks of age: AAP recommends 50 mg/kg every 12 hours in those weighing <1.2 kg and 50 mg/kg every 8 hours in those weighing ≥1.2 kg.²⁶¹

General Pediatric Dosage in Children 1 Month to 12 Years of Age

IV

25–50 mg/kg every 8 hours.^{1 38 103 107 217 254 261} Use 50 mg/kg every 8 hours in immunocompromised children or children with cystic fibrosis.^{1 28 30 108 126 128 129 149 217}

AAP recommends 75–100 mg/kg daily in 3 equally divided doses for the treatment of mild to moderate infections or 125–150 mg/kg daily in 3 equally divided doses for the treatment of severe infections.²⁶¹

General Pediatric Dosage in Children >12 Years of Age

IV

Use usual adult dosage.^{1 217} (See Adult Dosage under Dosage and Administration.)

Meningitis

IV

Some clinicians recommend 100–150 mg/kg daily in 2 or 3 equally divided doses for neonates ≤7 days of age and 150 mg/kg daily in 3 divided doses in older neonates and children.³⁵⁴

Because of a high rate of relapse, treatment duration should be ≥3 weeks for meningitis caused by gram-negative bacilli.^{335 337 354} In neonates, some clinicians recommend that treatment be continued for 2 weeks beyond the first sterile CSF culture or at least 3 weeks, whichever is longer.³⁵⁴

Burkholderia Infections†

Severe Melioidosis Caused by Burkholderia pseudomallei†

IV

60 mg/kg daily in 2 equally divided doses recommended by some clinicians for children <2 months of age or 100 mg/kg daily in 3 equally divided doses for children ≥2 months of age.³⁵⁷ Concomitant co-trimoxazole or doxycycline may be indicated in septicemic or other severe cases.³⁵⁷

Continue initial parenteral regimen for at least 14 days and until there is clinical improvement.^{355 356 357} When appropriate, switch to an oral maintenance regimen (e.g., oral co-trimoxazole with or without oral doxycycline) and continue for at least 3–6 months to prevent recrudence or relapse.^{355 356 357} More prolonged oral maintenance therapy (up to 12 months) may be necessary, depending on the response to therapy and severity of initial illness.^{356 357}

Empiric Therapy in Febrile Neutropenic Children†

IV

50 mg/kg (maximum 2 g) every 8 hours has been used in pediatric patients ≥2 years of age.³⁴⁷

Adults

General Adult Dosage

Less Severe Infections

IV or IM

1 g every 8–12 hours.^{1 217}

Severe or Life-threatening Infections

IV

2 g every 8 hours,¹ especially in immunocompromised patients.¹

Bone and Joint Infections

IV

2 g every 12 hours.^{1 104 217}

Intra-abdominal and Gynecologic Infections

Serious Infections

IV

2 g every 8 hours.^{1 217}

Meningitis

IV

2 g every 8 hours.^{1 217 354} Duration of treatment is ≥3 weeks for meningitis caused by susceptible gram-negative bacilli.^{335 337 354}

Respiratory Tract Infections

Uncomplicated Pneumonia

IV or IM

0.5–1 g every 8 hours.^{1 217}

Pseudomonas Lung Infections in Cystic Fibrosis Patients

IV

30–50 mg/kg every 8 hours (up to 6 g daily).^{1 28 30 50 125 126 128 129 149 217 246 348}

Clinical improvement may occur, but bacteriologic cures should not be expected in patients with chronic respiratory disease and cystic fibrosis.^{1 28 119 125 126 132 149 150 208 217}

Skin and Skin Structure Infections

Mild Infections

IV or IM

0.5–1 g every 8 hours.^{1 104 217}

Urinary Tract Infections (UTIs)

Uncomplicated Infections

IV or IM

250 mg every 12 hours.^{1 104 217}

Complicated Infections

IV or IM

500 mg every 8–12 hours.^{1 104 217}

Burkholderia Infections†

Severe Melioidosis Caused by Burkholderia pseudomallei†

IV

40 mg/kg every 8 hours recommended by US Army Medical Research Institute of Infectious Diseases (USAMRIID).³⁵⁶ Others recommend 2 g every 8 hours (up to 6 g daily)³⁵⁷ or 50 mg/kg (up to 2 g) every 6 hours.^{355 358} Concomitant co-trimoxazole or doxycycline may be indicated in septicemic or other severe cases.^{355 356 357 358}

Continue initial parenteral regimen for at least 14 days and until there is clinical improvement.^{355 356 357 358} When appropriate, switch to an oral maintenance regimen (e.g., oral co-trimoxazole with or without oral doxycycline) and continue for at least 3–6 months to prevent recrudence or relapse.^{355 356 357 358} More prolonged oral maintenance therapy (up to 12 months) may be necessary, depending on the response to therapy and severity of initial illness.^{356 357}

Prescribing Limits

Pediatric Patients

Maximum 6 g daily.¹

Adults

Maximum 6 g daily.^{1 217 221 225}

Special Populations

Hepatic Impairment

Dosage adjustments not required unless renal function also impaired.^{1 150 217}

Renal Impairment

Reduce dosage in patients with Cl_cr ≤50 mL/minute.^{1 217}

Manufacturers recommend that adults with Cl_cr ≤50 mL/minute receive an initial loading dose of 1 g and a maintenance dosage based on Cl_cr.^{1 217} (See Table.)

Maintenance Dosage for Adults with Renal Impairment1

Clcr (mL/minute)	Dosage
31–50	1 g every 12 h
16–30	1 g every 24 h
6–15	500 mg every 24 h
<5	500 mg every 48 h

Patients with renal impairment and severe infections who would generally receive 6 g daily if renal function were normal: increase dosage in table by 50% or dosing interval may be increased appropriately.¹

Patients undergoing hemodialysis: given an initial loading dose of 1 g followed by 1 g after each hemodialysis period.^{1 217 221}

Patients undergoing intraperitoneal dialysis or CAPD: given an initial loading dose of 1 g followed by 500 mg every 24 hours.^{1 217 221}

Geriatric Patients

Cautious dosage selection because of age-related decreases in renal function.¹ (See Renal Impairment under Dosage and Administration.)

Cautions for Ceftazidime

Contraindications

• 
  

  Known hypersensitivity to ceftazidime or other cephalosporins.¹

  
  

Warnings/Precautions

Warnings

Superinfection/Clostridium difficile-associated Diarrhea and Colitis (CDAD)

Possible emergence and overgrowth of nonsusceptible organisms with prolonged therapy.¹ Careful observation of the patient is essential.^{1 217} Institute appropriate therapy if superinfection occurs.^{1 217}

Treatment with anti-infectives alters normal colon flora and may permit overgrowth of Clostridium difficile.¹ C. difficile-associated diarrhea and colitis (CDAD; also known as antibiotic-associated diarrhea and colitis or pseudomembranous colitis) has been reported with nearly all anti-infectives, including ceftazidime, and may range in severity from mild diarrhea to fatal colitis.^{1 217} Hypertoxin producing strains of C. difficile are associated with increased morbidity and mortality since they may be refractory to anti-infectives and colectomy may be required.¹

Consider CDAD if diarrhea develops and manage accordingly.¹ Careful medical history is necessary since CDAD has been reported to occur as late as 2 months or longer after anti-infective therapy is discontinued.¹

If CDAD is suspected or confirmed, the anti-infective may need to be discontinued.¹ Some mild cases of CDAD may respond to discontinuance alone.^{1 217 339 340 341 342 343} Manage moderate to severe cases with fluid, electrolyte, and protein supplementation, anti-infective therapy active against C. difficile (e.g., oral metronidazole or vancomycin), and surgical evaluation when clinically indicated.^{1 217 339 340 341 342 343}

Neurotoxicity

Possibility of seizures, encephalopathy, coma, asterixis, neuromuscular excitability, and myoclonia if inappropriately high dosage used in patients with renal impairment.¹ (See Renal Impairment under Cautions.)

Sensitivity Reactions

Hypersensitivity Reactions

Possible hypersensitivity reactions, including rash (maculopapular or erythematous), pruritus, fever, eosinophilia, urticaria, anaphylaxis, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis.^{1 217 a}

If an allergic reaction occurs, discontinue and institute appropriate therapy as indicated (e.g., epinephrine, corticosteroids, maintenance of an adequate airway and oxygen).^{1 217}

Cross-hypersensitivity

Partial cross-sensitivity among cephalosporins and other β-lactam antibiotics, including penicillins and cephamycins.^{1 217 a}

Prior to initiation of therapy, make careful inquiry concerning previous hypersensitivity reactions to cephalosporins, penicillins, or other drugs.^{1 217} Cautious use recommended in individuals hypersensitive to penicillins:^{1 217 a} avoid use in those who have had an immediate-type (anaphylactic) hypersensitivity reaction and administer with caution in those who have had a delayed-type (e.g., rash, fever, eosinophilia) reaction.^a

General Precautions

History of GI Disease

Use with caution in patients with a history of GI disease, particularly colitis.^{1 217} (See Superinfection/Clostridium difficile-associated Diarrhea and Colitis under Cautions.)

Prolonged PT

Possibility of prolonged PT.^{1 217}

Monitor PT in patients at risk, including those with renal or hepatic impairment, poor nutritional state, receiving prolonged therapy, or stabilized on anticoagulant therapy.^{1 217} Administer vitamin K when indicated.^{1 217}

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of ceftazidime and other antibacterials, use only for treatment or prevention of infections proven or strongly suspected to be caused by susceptible bacteria.^{1 217}

When selecting or modifying anti-infective therapy, use results of culture and in vitro susceptibility testing.^{1 217} In the absence of such data, consider local epidemiology and susceptibility patterns when selecting anti-infectives for empiric therapy.^{1 217}

Resistance in Gram-negative Bacteria

Resistance caused by inducible type I β-lactamases can develop in some gram-negative bacilli (e.g., Enterobacter, Pseudomonas, Serratia) during treatment, leading to clinical failure in some cases.¹

When treating infections caused by these bacteria, perform periodic in vitro susceptibility testing when clinically appropriate.¹ If patient fails to respond to monotherapy, an aminoglycoside or similar agent should be considered.¹

Risk of Distal Necrosis

Possibility of distal necrosis after inadvertent intra-arterial administration.¹

Sodium Content

Vials, pharmacy bulk packages, and ADD-Vantage vials contain ceftazidime admixed with sodium carbonate to facilitate dissolution.^{1 217 233} These preparations contain approximately 54 mg (2.3 mEq) of sodium per g of ceftazidime.^{1 217 233}

Specific Populations

Pregnancy

Category B.¹

Lactation

Distributed into milk in low concentrations; use with caution.¹

Geriatric Use

No overall differences in safety and efficacy in those ≥65 years of age compared with younger adults, but the possibility of increased sensitivity in some geriatric individuals cannot be ruled out.¹

Substantially eliminated by kidneys; risk of toxicity may be greater in those with impaired renal function.¹ Select dosage with caution and assess renal function periodically because of age-related decreases in renal function.¹ (See Renal Impairment under Dosage and Administration.)

Hepatic Impairment

Pharmacokinetics not affected.¹

Renal Impairment

Possible decreased clearance and increased serum half-life.¹

Neurotoxicity reported in some patients with renal impairment who received dosage inappropriately high for their renal status.¹ (See Neurotoxicity under Cautions.)

Dosage adjustments necessary in patients with Cl_cr ≤50 mL/minute.¹ See Renal Impairment under Dosage and Administration.

Common Adverse Effects

GI effects, hypersensitivity reactions, local reactions at IV injection sites.¹

Interactions for Ceftazidime

Specific Drugs and Laboratory Tests

Drug or Test	Interaction	Comments
Aminoglycosides	Nephrotoxicity reported with concomitant use of some cephalosporins and aminoglycosides1 209 217 In vitro evidence of additive or synergistic antibacterial activity against Pseudomonas and Enterobacteriaceae1 50 63 90 147 186 187 191 217	Carefully monitor renal function, especially if high aminoglycoside dosage is used or if therapy is prolonged1 217
Chloramphenicol	In vitro evidence of antagonism against gram-negative bacilli1 270 271 272 273 274	Avoid concomitant use1 274
Probenecid	No appreciable effect on pharmacokinetics of ceftazidime1 5 10 24 50 130 147 164 217
Tests for glucose	Possible false-positive reactions in urine glucose tests using Clinitest, Benedict’s solution, or Fehling’s solution1 173 a	Use glucose tests based on enzymatic glucose oxidase reactions (e.g., Clinistix, Tes-Tape)1 173 a

Ceftazidime Pharmacokinetics

Absorption

Bioavailability

Not absorbed from GI tract; must be given parenterally.^{3 50}

Following IM administration, peak serum concentrations attained in approximately 1 hour.^{1 6 12 217} May be absorbed more slowly in women than in men following IM injection into the gluteus maximus or vastus lateralis.⁶ In women, peak serum concentrations may be lower following IM injection into the gluteus maximus than into the vastus lateralis.⁶

In patients with end-stage chronic renal failure who receive a single dose of the drug via an intraperitoneal catheter, peak serum concentrations attained 2.75 hours after the dose.²⁷

Distribution

Extent

Widely distributed into body tissues and fluids including the gallbladder,^{24 169 255} bone,^{1 3 23 147 168 203}