Ceftazidime

* semisynthetic, broad-spectrum cephalosporin
* activity against a wide range of gram-positive andgram-negative organisms
* Effective in LRTI, skin & skin structure infections, UTI, bacterial septicemia, gynaecological infections, intra-abdominal Infections, CNS infections and bone & joint infections
* Well tolerated

 

Mechanism of Action

* Bactericidal
* Inhibition of cell-wall synthesis

 

Antibacterial Spectrum

Aerobes, Gm -ve : E. coli, Citrobacter spp., Enterobacter spp., H. influenzae, Klebsiella spp. N. meningitidis, P. mirabilis, P, vulgaris, Pseudomonas spp. and Serratia spp.

Aerobes, Gm +ve : Staph. aureus, Group B streptococci, Strept. pneumoniae and Strept. pyogenes (group A beta-hemolytic)

Anaerobes: Bacteroides spp. Ceftazidime and the aminoglycosides are synergistic against Ps. aeruginosa & Enterobacteriaceae. Ceftazidime and carbenicillin are synergistic against Ps. aeruginosa

 

Resistance

* Resistance is rare
* Highly stable to beta-lactamases, plasmid or chromosomal, produced by both Gm-ve & Gm +ve organisms, including many strains resistant toampicillin and other cephalosporins

Pharmacokinetics

- Cmax 90 mcg/mL & 69 mcg/mL with 1gm IV administered over 5 minutes & over 20 to 30 mins respectively
- 80% to 90% of IM/IV dose excreted unchanged by kidneysover 24-hour period.
-MIC value generally < 16 mcg/ml

- Serum half-life after IV injections is approx 1.9 hrs; significantlyprolonged in impaired renal function

Indications

- LRTI including pneumonia
- Skin and Skin-Structure Infections
- Urinary Tract Infections
- complicated and uncomplicated
- Bacterial Septicemia
- Bone and Joint Infections
- Gynecologic Infections, including endometritis, pelvic cellulitis, and other infections of the female genital tract
- Intra-abdominal Infections, including peritonitis
- Central Nervous System Infections, including meningitis

 

Adverse Reactions

- Generally well tolerated
- Local effects i.e. phlebitis, pain at injection site; hypersensitivity reactions; gastrointestinal symptoms e.g. nausea, vomiting, diarrhoea, pseudomembranous colitis; CNS effects

Precautions & Contraindications

- Contraindicated in patients with known allergy to ceftizidime orcephalosporins
- Caution in patients with renal insufficiency, dosage should be reduced
- Inducible type I beta lactamse resistance can occur. Periodic susceptibility testing may be advisable during therapy. If response is inadequate, concomitant use with an aminoglycoside can be considered.- No evidence of harm in pregnancy or lactation, use with caution inpregnant & lactating women
- Cephalosporins may be associated with a fall in prothrombin activity

Dosage

For Patients 12 years and older
Usual recommended dosage - 1 gram IV or IM; q8-12h
Uncomplicated & complicated urinary tract infections - 250-500 mg IV or IM; q8-12h
Bone and joint infections - 2 grams IV; q12 h
Uncomplicated pneumonia; mild skin and skin-structure infections - 500 mg-1 gram IV or IM; q8h
Serious gynecologic and intra abdominal infections; meningitis; severe life-threatening infections, especially in immunocompromised patients - 2 grams IV; q8h
Lung infections caused by Pseudomonas Spp. In patients with cystic fibrosis with normal renal function - 30-50 mg/kg IV to a maximum of 6 grams per day; q8h
Impaired Hepatic Function: No adjustment in dosage is required for patients with hepatic dysfunction

 

Salient Features

- Activity against a wide range of gram-positive and gram-negative organisms
- Highly stable to Beta lactamases
- Wide distribution in the body
- Effective in LRTI, skin & skin structures, UTI,bacterial septicemia, gynaecological infections, Intra-abdominal Infections, CNS infections andbone & bone joint infections
- Resistance is rare
- Well tolerated