What is the recommended treatment for chlamydia and gonorrhea in a patient with documented anaphylaxis to penicillin (Penicillin Allergy)?

Treatment for Chlamydia and Gonorrhea in Patients with Documented Penicillin Anaphylaxis

For patients with documented anaphylaxis to penicillin, treat with azithromycin 1 g orally as a single dose for chlamydia plus either spectinomycin 2 g intramuscularly (if available) or a fluoroquinolone for gonorrhea, avoiding all cephalosporins due to cross-reactivity risk. 1

Chlamydia Treatment

• Azithromycin 1 g orally as a single dose is the optimal choice, achieving 97% cure rates with no cross-reactivity with penicillin 1
• Doxycycline 100 mg orally twice daily for 7 days is an equally effective alternative with 98% cure rates, offering the advantage of lower cost 1, 2
• Single-dose azithromycin provides superior compliance through directly observed therapy, which is critical in STI management where patient follow-through is often poor 3, 4
• The FDA approves azithromycin specifically for urethritis and cervicitis due to Chlamydia trachomatis, confirming its role as first-line therapy 5

Gonorrhea Treatment in Penicillin-Allergic Patients

Critical consideration: Cephalosporins are contraindicated in patients with severe IgE-mediated penicillin reactions (anaphylaxis) due to potential cross-reactivity. 6, 1

First-Line Option

• Spectinomycin 2 g intramuscularly as a single dose is the recommended alternative, with 98.2% cure rates for uncomplicated urogenital and anorectal gonorrhea 6, 1
• Spectinomycin is expensive and requires injection, but it is the safest option when cephalosporins are contraindicated 6

Alternative When Spectinomycin Unavailable

• Ciprofloxacin 500 mg orally as a single dose can be used if local resistance patterns permit 1, 2
• Fluoroquinolones should NOT be used in men who have sex with men (MSM), patients with recent foreign travel, or infections acquired in areas with known quinolone-resistant N. gonorrhoeae (QRNG) 6
• Ofloxacin 400 mg orally is another fluoroquinolone option with similar efficacy 2

Critical Pitfall: Pharyngeal Gonorrhea

• Spectinomycin has only 52% efficacy for pharyngeal infections and should never be used for this site 7
• If pharyngeal gonorrhea is suspected in a penicillin-allergic patient, fluoroquinolones are the only viable option (if susceptibility permits), as spectinomycin is completely unreliable at this anatomic site 7
• Pharyngeal infections are significantly more difficult to eradicate and serve as reservoirs for antimicrobial resistance development 7

Recommended Treatment Algorithm

For uncomplicated urogenital/rectal infections:

1. Azithromycin 1 g orally (single dose) for chlamydia coverage 1, 5
2. PLUS Spectinomycin 2 g IM (single dose) for gonorrhea 1
3. If spectinomycin unavailable AND local resistance patterns favorable: Ciprofloxacin 500 mg orally (single dose) 1

For pharyngeal infections:

1. Azithromycin 1 g orally (single dose) for chlamydia coverage 7
2. PLUS Ciprofloxacin 500 mg orally (single dose) for gonorrhea—spectinomycin is NOT an option 7
3. Verify local fluoroquinolone susceptibility before prescribing 6

Why Cephalosporins Must Be Avoided

• Patients with documented anaphylaxis to penicillin have severe IgE-mediated reactions that contraindicate cephalosporins 6
• Approximately 90% of patients reporting penicillin allergy are no longer allergic, but those with documented anaphylaxis represent true high-risk cases 1
• Cephalosporins share similar side chains with penicillins and can trigger cross-reactive anaphylaxis in these patients 6
• The CDC explicitly states that persons who cannot tolerate cephalosporins should be treated with spectinomycin 6

Partner Management and Follow-Up

• All sexual partners from the preceding 60 days must be evaluated and treated with the same dual therapy regimen for both gonorrhea and chlamydia 6, 7
• Instruct patients to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of multi-day regimens 1
• Test of cure is NOT routinely required for patients treated with recommended regimens unless symptoms persist 6, 7
• If symptoms persist, obtain culture for N. gonorrhoeae with antimicrobial susceptibility testing 6

Common Pitfalls to Avoid

• Never use azithromycin 2 g alone for gonorrhea—it causes significant gastrointestinal distress and has insufficient efficacy (93%) 6
• Never use macrolides (erythromycin) for gonorrhea—N. gonorrhoeae in the United States is not adequately susceptible 6
• Never assume spectinomycin will work for pharyngeal infections—efficacy is only 52% at this site 7
• Do not use fluoroquinolones in MSM or patients with recent travel to high-resistance areas without confirming susceptibility 6
• Gastrointestinal side effects occur in 19% of azithromycin-treated patients but are generally mild 4