Can ertapenem be given to a patient with a levofloxacin (fluoroquinolone) allergy?

Ertapenem Can Be Safely Used in Patients with Levofloxacin Allergy

Ertapenem can be safely administered to patients with a levofloxacin (fluoroquinolone) allergy as there is no significant cross-reactivity between carbapenems and fluoroquinolones. 1

Understanding Antibiotic Classes and Cross-Reactivity

Ertapenem and levofloxacin belong to completely different antibiotic classes:

• Ertapenem: A carbapenem (β-lactam class)
• Levofloxacin: A fluoroquinolone

These antibiotics have different chemical structures and mechanisms of action, which explains the lack of cross-reactivity between them.

Evidence Supporting Safety

The Dutch Working Party on Antibiotic Policy (SWAB) guideline clearly indicates that there is no cross-reactivity between β-lactam antibiotics (including carbapenems like ertapenem) and non-β-lactam antibiotics (such as fluoroquinolones like levofloxacin) 1. The guideline specifically addresses fluoroquinolone allergies and does not list carbapenems as cross-reactive with them.

For intra-abdominal infections, the World Society of Emergency Surgery guidelines specifically mention carbapenems (including ertapenem) as appropriate alternatives when other antibiotics cannot be used 1. This further supports the safety of using ertapenem in patients with fluoroquinolone allergies.

Clinical Decision-Making Algorithm

When considering ertapenem for a patient with levofloxacin allergy:

1. Confirm the nature of the levofloxacin allergy:

   • Document reaction type (immediate vs. delayed)
   • Assess severity of previous reaction

2. Proceed with ertapenem administration:

   • No skin testing required before administration
   • Standard dosing protocols can be followed
   • No special monitoring required beyond standard practice

3. Monitor for unrelated adverse reactions:

   • While cross-reactivity is not expected, monitor for independent adverse reactions to ertapenem

Important Considerations

• Fluoroquinolone allergies (including levofloxacin) are the most frequently reported non-β-lactam antibiotic allergies, but the absolute risk of severe reactions is low (1.8-2.3 per 100,000 days of treatment) 1

• Carbapenems like ertapenem have been successfully used in patients with various antibiotic allergies, including those to fluoroquinolones 2

• While there is cross-reactivity between some β-lactam antibiotics (e.g., penicillins and some cephalosporins), there is no documented cross-reactivity between β-lactams and fluoroquinolones 1, 3

Caution

Although not relevant to the levofloxacin-ertapenem cross-reactivity question, it's worth noting that patients with true penicillin allergies may have some cross-reactivity with carbapenems, though recent studies show this risk is much lower than previously thought (less than 1% rather than the 47.4% historically reported) 3.

In conclusion, ertapenem is a safe alternative for patients with levofloxacin allergy, and no special precautions are needed when administering ertapenem to these patients.