From the Guidelines
Doxycycline is a suitable antibiotic for a patient allergic to penicillin and azithromycin. The recommended dose is 100 mg orally twice per day for 7-14 days, depending on the specific infection being treated 1.
Alternative Options
- Clindamycin can be used as an alternative, with a dose of 300-450 mg orally three times per day or 600 mg intravenously every 8 hours 1.
- Cephalexin is another option, with a dose of 500 mg orally four times per day 1.
- TMP-SMZ can also be considered, with a dose of 1 or 2 double-strength tablets orally twice per day 1. It's essential to consult with an allergist or infectious disease specialist to determine the best course of treatment, considering the patient's specific allergy profile and infection type.
Key Considerations
- Cross-reactivity: When using alternative antibiotics, consider potential cross-reactivity with azithromycin, especially with macrolides like erythromycin and clarithromycin 1.
- Side effects: Fluoroquinolones like ciprofloxacin and levofloxacin can be used as a last resort, but their use should be reserved due to potential side effects 1.
From the FDA Drug Label
Erythromycin (oral forms only) is an alternative choice of treatment for primary syphilis in patients allergic to the penicillins. Erythromycin tablets are indicated for the treatment of penicillin-allergic patients. In patients who are allergic to penicillin and sulfonamides, oral erythromycin is recommended by the American Heart Association in the long-term prophylaxis of streptococcal pharyngitis (for the prevention of recurrent attacks of rheumatic fever).
Erythromycin is a suitable antibiotic for a patient allergic to penicillin. However, the label does not provide information about azithromycin allergy, but since erythromycin is an alternative for penicillin allergy, it can be considered. 2
From the Research
Antibiotic Options for Patients Allergic to Penicillin and Azithromycin
- For patients allergic to penicillin, beta-lactam antibiotics may be used safely if the patient has an unknown or possible penicillin allergy, or a drug fever or rash 3.
- However, if the patient has a history of hives or anaphylactic reactions to penicillin, penicillins or beta-lactams should not be used 3.
- Azithromycin is not a suitable option for this patient as they are allergic to it.
- Alternative antibiotics that do not cross-react with penicillins or beta-lactams can be considered, such as metronidazole, doxycycline, and levofloxacin 4.
- Fluoroquinolones and macrolides can also be evaluated using drug challenge as a method for assessment of allergy 5.
Considerations for Antibiotic Selection
- The patient's allergy history should be carefully evaluated to determine the risk of an allergic reaction to different antibiotics 6.
- Patients with a low-risk allergy history may be able to tolerate certain antibiotics, while those with a high-risk history may require alternative treatments 6.
- Clinicians should consider the potential for cross-reactivity between different antibiotics and the patient's known allergies when selecting an antibiotic 3, 6.