Treatment for Uncomplicated Gonorrhea-Chlamydia Co-Infection with Penicillin Allergy
For adults with penicillin allergy and uncomplicated gonorrhea-chlamydia co-infection, administer ceftriaxone 500 mg intramuscularly as a single dose PLUS azithromycin 1 g orally as a single dose. 1
Why Ceftriaxone Despite Penicillin Allergy
Penicillin allergy does NOT contraindicate cephalosporin use in most patients. Cross-reactivity between penicillins and third-generation cephalosporins like ceftriaxone is extremely low (approximately 1-3%), and ceftriaxone remains the recommended first-line treatment even in patients reporting penicillin allergy. 1, 2
Ceftriaxone 500 mg IM plus azithromycin 1 g orally achieves 98.9% cure rates for urogenital and anorectal gonorrhea, and is the only reliably effective regimen for pharyngeal infections. 3, 1
The dual therapy addresses both gonorrhea and presumptive chlamydial co-infection, which occurs in 40-50% of gonorrhea cases. 1, 4
Only for TRUE Severe Cephalosporin Allergy
If the patient has documented severe, IgE-mediated cephalosporin allergy (anaphylaxis, angioedema, bronchospasm), use gentamicin 240 mg intramuscularly PLUS azithromycin 2 g orally as a single dose. 1, 5
Critical Limitations of This Alternative
Gentamicin has significantly inferior efficacy for pharyngeal gonorrhea (only 80% cure rate vs. 96% for ceftriaxone) and rectal gonorrhea (90% vs. 98%). 6, 7
Mandatory test-of-cure at 1 week is required when using gentamicin, using culture (preferred) or nucleic acid amplification testing. 1, 2
Genital-only infections respond adequately to gentamicin (94% cure rate), making this a reasonable alternative for isolated urogenital disease in patients with true cephalosporin allergy. 6, 7
A recent randomized trial demonstrated 100% cure rates for rectal and pharyngeal gonorrhea when gentamicin 240 mg was combined with azithromycin 2 g (rather than 1 g), supporting the higher azithromycin dose in this regimen. 5
Regimens to NEVER Use
Never use fluoroquinolones (ciprofloxacin, ofloxacin) due to widespread resistance, despite historical cure rates of 99.8%. 3, 1
Never use azithromycin 1 g alone for gonorrhea due to insufficient efficacy (only 93% cure rate) and rapid resistance emergence. 3, 1
Never use spectinomycin for pharyngeal infections due to only 52% efficacy at this site. 3, 1
Follow-Up Requirements
Patients treated with the recommended ceftriaxone-based regimen do NOT require routine test-of-cure unless symptoms persist. 1, 2
All patients should be retested approximately 3 months after treatment due to high reinfection rates (not treatment failure). 1, 2
If symptoms persist after treatment, obtain culture with antimicrobial susceptibility testing immediately and report to local public health officials within 24 hours. 1, 2
Partner Management
All sexual partners from the preceding 60 days must be evaluated and treated with the same dual therapy regimen (ceftriaxone 500 mg IM plus azithromycin 1 g orally), regardless of symptoms or test results. 1, 4, 2
Patients should abstain from sexual intercourse until therapy is completed and both patient and partners are asymptomatic. 3, 1
Consider expedited partner therapy with oral cefixime 400 mg plus azithromycin 1 g if partners cannot access timely clinical evaluation. 1, 2
Special Populations
In pregnancy, use ceftriaxone 500 mg IM plus azithromycin 1 g orally; never use doxycycline, quinolones, or tetracyclines. 1, 4, 2
For men who have sex with men (MSM), ceftriaxone is the only recommended treatment due to higher prevalence of resistant strains; do not use patient-delivered partner therapy in this population due to high risk of undiagnosed HIV or other STIs. 1, 2