Ceftazidime is a third-generation cephalosporin antibiotic administered parenterally, either intravenously or intramuscularly. It is highly effective against a broad range of gram-negative bacteria, including Pseudomonas aeruginosa. Although it shows in vitro activity against gram-positive organisms, it is rarely used clinically for gram-positive infections. Ceftazidime is commonly prescribed for conditions such as meningitis, lower respiratory tract infections, febrile neutropenia, urinary tract infections, pelvic inflammatory disease, and skin and soft tissue infections.
Ceftazidime, a third-generation cephalosporin first approved in 1985, has been combined with the novel β-lactamase inhibitor (BLI) avibactam. This combination received approval on February 25, 2015, for the treatment of complicated intra-abdominal infections (cIAI) — in conjunction with metronidazole — and complicated urinary tract infections (cUTI), including pyelonephritis.
BRAND NAMES
Brand names for the antibiotic ceftazidime include Fortaz, Tazicef, and Tazidime. There are also several other brand names, which can vary by manufacturer and region. Ceftazidime is also available as a generic medication.
Common brand names:
Fortaz
Tazicef
Tazidime
Tazid
MECHANISM OF ACTION
It works by inhibiting the synthesis of the bacterial cell wall, which is vital for the bacteria's survival. It achieves this by binding to and inactivating penicillin-binding proteins (PBPs) inside the bacterial cell. This process leads to the lysis, or breakdown, of the bacterial cell and ultimately causes its death.
PHARMACOKINETICS:
Absorption
In healthy males, intravenous ceftazidime (500 mg–2 g) produced Cmax values of 42–170 μg/mL immediately after infusion. Intramuscular administration of 1 g reached a Cmax of 37–43 mg/L after about one hour, with serum levels remaining above 4 μg/mL for six to eight hours.
Distribution
Ceftazidime exhibits a volume of distribution ranging from 15 to 20 liters.
Metabolism
The antibiotic Ceftazidime undergoes negligible metabolism in the human body. Instead of being broken down, it is eliminated almost entirely unchanged via the kidneys — reflecting its distinctive pharmacologic profile.
Excretion
The antibiotic Ceftazidime is excreted primarily unchanged via the kidneys, predominantly through glomerular filtration. It undergoes minimal metabolism, and liver function has little impact on its clearance.
PHARMACODYNAMICS
Cefotaxime is a third-generation cephalosporin antibiotic that exhibits bactericidal activity by binding to penicillin-binding proteins (PBPs) within bacterial cell walls. This binding inhibits the final transpeptidation step in peptidoglycan synthesis, leading to compromised cell wall integrity and subsequent bacterial cell lysis.
ADMINISTRATION
Ceftazidime is an antibiotic administered via injection, either intravenously (into a vein) or intramuscularly (into a muscle). It is supplied as a powder that requires reconstitution with a suitable diluent before use. The specific route, dosage, and frequency of administration are determined by a healthcare professional based on factors such as the type and severity of the infection, as well as the patient's overall condition and renal function.
DOSAGE AND STRENGTH
Ceftazidime is a third-generation cephalosporin antibiotic available in 500 mg, 1 g, 2 g, and 10 g vials, administered intravenously (IV) or intramuscularly (IM). For adults, the typical dosage is 1 gram every 8 to 12 hours, with higher doses for severe infections. In pediatric patients, dosing ranges from 30 to 50 mg/kg every 8 hours, up to a maximum of 6 grams per day. Renal function significantly influences dosing; adjustments are necessary for patients with creatinine clearance (CrCl) less than 50 mL/min. For instance, in patients with CrCl 6–15 mL/min, 500 mg every 24 hours is recommended. Always consult a healthcare professional for personalized dosing.
DRUG INTERACTIONS
The antibiotic ceftazidime can have serious to minor drug interactions with certain vaccines, other antibiotics, hormonal contraceptives, anticoagulants, and diuretics. These interactions can lead to reduced drug efficacy or increased risk of toxicity, especially in patients with impaired kidney function.
Serious drug interactions
Live bacterial vaccines (BCG, cholera, and typhoid): Ceftazidime decreases the effectiveness of these vaccines through pharmacodynamic antagonism.
Recommendation: Live bacterial vaccines should not be co-administered with systemic antibiotics
FOOD INTERACTIONS
Ceftazidime typically does not interact with most foods or beverages, allowing for normal eating habits during treatment. However, certain formulations contain sodium carbonate, providing approximately 53 mg of sodium per gram of ceftazidime. This sodium content should be considered in patients with conditions requiring sodium restriction, such as congestive heart failure, hypertension, or fluid retention.
CONTRAINDICATIONS
Ceftriaxone is contraindicated in individuals with known hypersensitivity to ceftriaxone, other cephalosporins, or any components of the formulation. Patients with a history of severe allergic reactions (e.g., anaphylaxis, angioedema, urticaria) to penicillins or other beta-lactam antibiotics may also be at increased risk of hypersensitivity to ceftriaxone
SIDE EFFECTS
Allergic reaction: Hypersensitivity response
Numbness, tingling, burning pain: Paresthesia or neuropathic discomfort
Headache, dizziness: Cephalgia and light-headedness
Nausea, vomiting, diarrhea, stomach pain: Gastrointestinal distress
OVER DOSE
Ceftazidime overdose is a medical emergency that can cause severe neurological symptoms, including seizures and coma. If an overdose is suspected, call a local poison control center or emergency services immediately.
TOXICITY
Ceftazidime can cause serious toxicity, most notably neurotoxicity, especially in patients with pre-existing renal impairment where it can accumulate to dangerous levels. An overdose in these patients can lead to severe neurological symptoms, including seizures and coma.
