Azithromycin Safety in Patients with Clarithromycin (Biaxin) Allergy
Critical Clarification
First, there appears to be confusion in your question: Biaxin is the brand name for clarithromycin (a macrolide antibiotic), NOT clindamycin (a lincosamide antibiotic). Assuming you meant clarithromycin allergy, I will address azithromycin use in this context.
Direct Answer
You should avoid azithromycin in patients with a history of allergic reaction to clarithromycin (Biaxin), as both are macrolide antibiotics and cross-reactivity within the same antibiotic class is expected. 1
Reasoning Based on Guidelines
Cross-Reactivity Within Antibiotic Classes
The 2023 Dutch Working Party on Antibiotic Policy (SWAB) guideline provides clear direction for non-beta-lactam antibiotic allergies:
For severe reactions: The guideline strongly recommends avoiding the culprit non-beta-lactam antibiotic (NBLA) and all other antibiotics within the same class, regardless of time elapsed since the reaction. 1
For non-severe reactions: Even when the index reaction was non-severe, the culprit NBLA and all other antibiotics within the same class can only be re-introduced in a controlled clinical setting with trained personnel and emergency treatment availability. 1
Why This Matters for Your Patient
Clarithromycin and azithromycin are both macrolides - they share the same antibiotic class and have similar mechanisms of action (binding to the 50S ribosomal subunit). 2, 3, 4
Cross-reactivity is expected within macrolide antibiotics because they share structural similarities and immunologic recognition patterns. 1
The guideline explicitly groups clarithromycin and azithromycin together as macrolides when discussing antibiotic allergy management. 1
Clinical Algorithm
Step 1: Determine severity of the original clarithromycin reaction
- Severe reactions include: anaphylaxis, angioedema, severe urticaria, Stevens-Johnson syndrome, or other life-threatening manifestations
- Non-severe reactions include: mild rash, mild urticaria without systemic symptoms, or gastrointestinal intolerance
Step 2: If the reaction was severe
- Absolutely avoid azithromycin 1
- Choose an antibiotic from a different class entirely (e.g., fluoroquinolones, tetracyclines, or beta-lactams if no penicillin allergy)
Step 3: If the reaction was non-severe AND you have no alternative
- Azithromycin could potentially be given only in a controlled hospital/clinic setting with monitoring 1
- This requires availability of emergency medications (epinephrine, antihistamines, corticosteroids) and trained personnel
- This is NOT appropriate for outpatient prescribing
Step 4: Consider alternative antibiotics from different classes
- For respiratory infections: fluoroquinolones (levofloxacin, moxifloxacin) or doxycycline 5
- For dental infections: clindamycin (a lincosamide, NOT a macrolide) 5, 6
- For skin infections: cephalosporins (if no penicillin allergy) or fluoroquinolones
Important Caveats
Do not confuse gastrointestinal side effects with true allergy. If the patient's "allergy" to clarithromycin was only nausea or diarrhea without immunologic symptoms (rash, hives, swelling), this represents intolerance rather than allergy, and azithromycin may be safer. However, azithromycin also causes gastrointestinal side effects in many patients. 2, 3
One small 1994 study showed azithromycin was safe in 48 patients with penicillin/cephalosporin allergies 7, but this does NOT address cross-reactivity within the macrolide class itself.
Erythromycin-resistant organisms are also resistant to azithromycin 3, and the same principle applies to allergic cross-reactivity within the macrolide class.
Bottom Line
Unless the original "allergy" was merely gastrointestinal intolerance (not a true immunologic reaction), you should select an antibiotic from a completely different class rather than risk cross-reactivity between two macrolides. 1 If azithromycin is absolutely necessary and the original reaction was non-severe, administration must occur in a monitored clinical setting. 1