What are the treatments for sexually transmitted diseases (STDs)?

Treatment of Sexually Transmitted Diseases (STDs)

Treatment for STDs is pathogen-specific, with azithromycin 1 g orally as a single dose or doxycycline 100 mg orally twice daily for 7 days serving as the cornerstone regimens for the most common bacterial STDs (chlamydia and non-gonococcal urethritis), while gonorrhea requires ceftriaxone 125-250 mg IM, and viral STDs like herpes are managed with valacyclovir. 1, 2, 3

Bacterial STDs

Chlamydia trachomatis Infections

Recommended first-line regimens:

• Azithromycin 1 g orally in a single dose 1, 2
• Doxycycline 100 mg orally twice daily for 7 days 1

Both regimens demonstrate equivalent efficacy (95-100% cure rates), but azithromycin offers the critical advantage of directly observed single-dose therapy, which significantly improves compliance and is particularly valuable in patients unlikely to complete a 7-day regimen 1, 4, 5. The single-dose azithromycin regimen has been shown to be as effective as the 7-day doxycycline course in eradicating uncomplicated chlamydial genital infections 5, 6.

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
• Ofloxacin 300 mg orally twice daily for 7 days 1
• Levofloxacin 500 mg orally once daily for 7 days 1

Gonorrhea (Neisseria gonorrhoeae)

Recommended regimen:

• Ceftriaxone 125 mg IM in a single dose 1
• PLUS concurrent treatment for chlamydia (azithromycin 1 g or doxycycline as above) due to frequent coinfection 1

Alternative regimens:

• Cefixime 400 mg orally 1
• Ciprofloxacin 500 mg orally (only in areas without quinolone resistance) 1
• Ofloxacin 400 mg orally (only in areas without quinolone resistance) 1

Critical caveat: Quinolone-resistant gonorrhea has been reported from Southeast Asia, Hawaii, and California. Patients with recent travel to these areas or sexual partners from these regions should receive cephalosporin-based regimens, not quinolones 1. Spectinomycin 2 g IM remains an option for cephalosporin-allergic patients when quinolones cannot be used, though it is only 52% effective against pharyngeal infections 1.

Non-Gonococcal Urethritis (NGU) and Cervicitis

Presumptive treatment regimens (same as chlamydia):

• Azithromycin 1 g orally in a single dose 1
• OR Doxycycline 100 mg orally twice daily for 7 days 1

Presumptive therapy should be provided for patients at increased risk (age <25 years, new or multiple sex partners, unprotected sex), especially if follow-up cannot be ensured 1. Consider concurrent gonorrhea treatment if local prevalence exceeds 5% in the patient population 1.

Trichomoniasis

Recommended regimen:

• Metronidazole 2 g orally in a single dose 1

This should be included in presumptive treatment regimens for cervicitis when trichomoniasis is detected or suspected 1.

Syphilis (Treponema pallidum)

Treatment depends on stage:

• Early syphilis: Parenteral penicillin G is the drug of choice 1
• Pregnancy: Penicillin is mandatory; penicillin-allergic women must be desensitized and treated with penicillin as no proven alternatives exist for treating syphilis in pregnancy 1

The appropriate dose and duration depend on the clinical stage of syphilis 1.

Lymphogranuloma Venereum (LGV)

Recommended regimen:

• Doxycycline 100 mg orally twice daily for 21 days 1

Alternative:

• Erythromycin base 500 mg orally four times daily for 21 days 1

Chancroid (Haemophilus ducreyi)

Treatment is indicated for genital ulcer disease in men, though efficacy in women has not been established due to limited clinical trial data 2.

Viral STDs

Genital Herpes (HSV)

Initial episode:

• Valacyclovir is indicated for treatment of initial genital herpes episodes in immunocompetent adults 3
• Treatment should be initiated within 72 hours of symptom onset 3

Recurrent episodes:

• Valacyclovir for treatment when initiated within 24 hours of symptom onset 3

Suppressive therapy:

• Valacyclovir for chronic suppression in immunocompetent and HIV-infected adults 3
• Efficacy beyond 1 year in immunocompetent patients and beyond 6 months in HIV-infected patients has not been established 3

Transmission reduction:

• Valacyclovir is indicated for reducing transmission in immunocompetent adults, though efficacy beyond 8 months has not been established 3

Herpes Zoster (Shingles)

• Valacyclovir for treatment in immunocompetent adults when initiated within 72 hours of rash onset 3

Special Populations

Pregnancy

Critical modifications:

• Avoid doxycycline and quinolones (contraindicated) 1
• Chlamydia: Erythromycin or amoxicillin 1
• Gonorrhea: Cephalosporin (ceftriaxone preferred) or spectinomycin 2 g IM if cephalosporin-allergic 1
• Syphilis: Penicillin only; desensitize if allergic 1
• LGV: Erythromycin (azithromycin may be useful but lacks published safety data) 1

HIV-Infected Patients

HIV-infected patients should receive the same treatment regimens as HIV-negative patients for most STDs 1. However:

• Treatment of cervicitis in HIV-infected women is vital because it increases cervical HIV shedding; treatment reduces HIV shedding and may reduce transmission 1
• Fungi and mycobacteria are more likely to cause epididymitis in immunosuppressed patients 1
• Consider adding parenteral aminoglycoside (e.g., gentamicin) for granuloma inguinale in HIV-infected patients 1

Adolescents

Fluoroquinolones have traditionally not been recommended for patients <18 years due to concerns about articular cartilage damage in animal studies, though no joint damage has been observed in children treated with prolonged ciprofloxacin regimens. Adolescents weighing >45 kg can receive adult regimens 1.

Partner Management and Follow-Up

Essential components:

• Notify and treat all sex partners within 60 days preceding symptom onset 1
• Abstain from sexual intercourse until 7 days after single-dose therapy or after completion of 7-day regimens 1
• Rescreening: Consider rescreening for chlamydia 3-4 months after treatment, especially in adolescents, due to high reinfection rates 1
• Test of cure: Not necessary after azithromycin or doxycycline unless symptoms persist or reinfection is suspected 1

Persistent or Recurrent Infections

Management approach:

• Document objective signs of infection before retreatment 1
• Evaluate for reexposure to untreated partners 1
• If compliant with initial treatment and no reexposure, consider culture for Trichomonas vaginalis and assess for tetracycline-resistant Ureaplasma urealyticum 1
• For persistent cervicitis without identified pathogen, repeated antibiotic therapy has undefined value 1

Common Pitfalls to Avoid

• Do not treat symptoms alone without documenting urethritis or cervicitis (except in high-risk patients unlikely to return) 1
• Do not use quinolones for gonorrhea in patients with recent travel to Asia, Pacific, Hawaii, or California due to resistance 1
• Do not rely on azithromycin to treat syphilis at recommended doses for other STDs 2
• Always perform syphilis serology in patients with sexually transmitted urethritis or cervicitis, as high-dose short-course antimicrobials may mask incubating syphilis 2
• Do not use spectinomycin for pharyngeal gonorrhea without follow-up culture due to only 52% efficacy 1