Treatment of Common Sexually Transmitted Infections
For uncomplicated chlamydia and gonorrhea, treat with ceftriaxone 250 mg IM single dose PLUS doxycycline 100 mg orally twice daily for 7 days, or alternatively azithromycin 1 g orally as a single dose for chlamydia alone. 1
Chlamydia Treatment
Recommended first-line regimens:
Alternative regimens when first-line options cannot be used:
- Erythromycin base 500 mg orally four times daily for 7 days 1
- Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 1
- Levofloxacin 500 mg orally once daily for 7 days 1
- Ofloxacin 300 mg orally twice daily for 7 days 1
Single-dose azithromycin offers the advantage of directly observed therapy and improved compliance, though doxycycline remains highly effective. 1 Azithromycin is particularly effective against Mycoplasma genitalium infections, which may respond less well to doxycycline. 1
Gonorrhea Treatment
Recommended regimen for uncomplicated urogenital, rectal, or pharyngeal infection:
- Ceftriaxone 250 mg IM in a single dose 1
Critical consideration - dual therapy: Because patients with gonorrhea are frequently coinfected with chlamydia, routine cotreatment with a chlamydia-effective regimen is recommended unless a negative NAAT for chlamydia is available at the time of treatment. 1 This dual therapy approach also helps prevent development of antimicrobial-resistant gonorrhea. 1
Quinolone resistance warning: Fluoroquinolones (ciprofloxacin, ofloxacin) should NOT be used for gonorrhea treatment in men who have sex with men, in patients in California or Hawaii, or for infections acquired abroad due to widespread quinolone-resistant N. gonorrhoeae. 1 As of 2004,6.8% of U.S. isolates showed ciprofloxacin resistance, with 23.9% resistance among MSM. 1
Syphilis Treatment
For early syphilis (primary, secondary, or early latent <1 year):
- Benzathine penicillin G 2.4 million units IM in a single dose 1
For late latent syphilis or syphilis of unknown duration:
- Benzathine penicillin G 2.4 million units IM weekly for 3 consecutive weeks 1
Penicillin allergy management: Patients with documented penicillin allergy require oral desensitization before treatment, as no alternative regimen provides equivalent efficacy. 1 The desensitization protocol involves graduated doses of penicillin V suspension over 4-8 hours. 1
Post-Treatment Management
Abstinence requirements: Patients must abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen, and until all sex partners are treated. 1
Retesting at 3 months: All patients diagnosed with chlamydia or gonorrhea should be retested 3 months after treatment due to high reinfection rates, regardless of whether partners were treated. 3, 4
Partner notification: All sex partners from the past 60 days must be notified, evaluated, and treated presumptively for the same infection. 1, 3
Common Pitfalls to Avoid
Do not rely on symptoms alone: Approximately 70% of chlamydia and trichomoniasis infections and 53-100% of extragenital gonorrhea and chlamydia infections are asymptomatic. 4 This necessitates screening-based diagnosis rather than symptom-based approaches.
Do not miss syphilis screening: All patients treated for chlamydia or gonorrhea should receive syphilis serology and HIV testing, as antimicrobials used for short-course STI treatment may mask incubating syphilis. 1
Do not use inadequate gonorrhea treatment: Oral cephalosporins and fluoroquinolones are no longer recommended as first-line therapy due to resistance patterns. 1 Ceftriaxone IM remains the only reliably effective single-dose option.
Ensure diagnostic confirmation: While empiric treatment is appropriate in high-risk patients or those unlikely to follow up, nucleic acid amplification tests (NAATs) should be obtained whenever possible as they have 86-100% sensitivity and 97-100% specificity. 4 NAATs are FDA-cleared for endocervical swabs, vaginal swabs, male urethral swabs, and urine specimens. 1