Is there an oral version of Ceftazidime (ceftazidime) available?

Ceftazidime Is Only Available as an Injectable Formulation

Ceftazidime is only available as an injectable formulation administered intravenously or intramuscularly; there is no oral version of ceftazidime available for clinical use 1.

Available Formulations of Ceftazidime

Ceftazidime is a third-generation cephalosporin antibiotic that can only be administered through:

• Intravenous (IV) infusion
• Intramuscular (IM) injection

The typical dosing of injectable ceftazidime includes:

• 1-2 g IV every 8 hours for most infections 1
• 100-150 mg/kg per day divided every 8 hours for pediatric patients 1

Why No Oral Formulation Exists

There are several reasons why ceftazidime is not available in oral form:

1. Poor Oral Bioavailability: Like many third-generation cephalosporins, ceftazidime has poor oral absorption characteristics, making an oral formulation impractical 2.

2. Chemical Stability: The molecule is not stable in the acidic environment of the stomach, which would result in degradation before reaching therapeutic blood levels 3.

3. Pharmacokinetic Properties: Ceftazidime requires parenteral administration to achieve the necessary serum concentrations for treating serious infections 2, 3.

Alternative Oral Cephalosporins

For patients requiring an oral cephalosporin with similar coverage, the following alternatives are available:

• Cefixime: 400 mg orally in a single dose or divided doses 1, 4
• Cefpodoxime: 200 mg orally in a single dose or 10 mg/kg per day in 2 doses for children 1
• Cefuroxime axetil: 20-30 mg/kg per day in 2 doses 1
• Cephalexin: 50-100 mg/kg per day in 4 doses 1

Clinical Implications

The lack of an oral formulation has important clinical implications:

• Hospital-Based Treatment: Patients requiring ceftazidime typically need to be treated in a hospital setting or through home infusion services.

• Step-Down Therapy: When transitioning from IV to oral therapy, clinicians must select a different antibiotic. For example, in a study comparing IV/oral ciprofloxacin versus ceftazidime, patients on ceftazidime could not be switched to an oral form of the same drug 5.

• Pseudomonas Coverage: Ceftazidime is one of only two third-generation cephalosporins with good activity against Pseudomonas aeruginosa 6. When oral therapy is required for Pseudomonas infections, fluoroquinolones (e.g., ciprofloxacin) are often used instead 5.

Common Pitfalls to Avoid

1. Assuming Equivalence: Do not assume that oral cephalosporins have the same spectrum of activity as ceftazidime, particularly against Pseudomonas.

2. Inappropriate Substitution: Avoid substituting with oral cephalosporins for infections that specifically require ceftazidime's unique coverage profile.

3. Prolonged IV Therapy: When long-term therapy is needed, consider whether another antibiotic with an oral option might be more appropriate to facilitate outpatient management.

In conclusion, when ceftazidime is the optimal antibiotic choice based on culture results or empiric coverage needs, parenteral administration is the only option available.