What are the treatment regimens for common Sexually Transmitted Diseases (STDs)?

Treatment Regimens for Common Sexually Transmitted Diseases (STDs)

The first-line treatment for chlamydia is azithromycin 1 g orally in a single dose OR doxycycline 100 mg orally twice daily for 7 days, with gonorrhea requiring ceftriaxone 125 mg IM in a single dose. 1, 2

Chlamydia Treatment

First-Line Options

• Azithromycin: 1 g orally in a single dose 1, 2, 3

  • Advantages: Single-dose therapy improves compliance, directly observed therapy possible
  • Efficacy: 92% for urogenital infections, 76.4% for rectal infections 2

• Doxycycline: 100 mg orally twice daily for 7 days 1, 2

  • Advantages: Higher efficacy, especially for rectal infections
  • Efficacy: 95.5% for urogenital infections, 96.9% for rectal infections 2

Alternative Options

• 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
• For patients unable to tolerate high-dose erythromycin:
  • Erythromycin base: 250 mg orally four times daily for 14 days 1
  • Erythromycin ethylsuccinate: 400 mg orally four times daily for 14 days 1

Special Considerations for Pregnant Women

• Recommended regimens:
  • Erythromycin base: 500 mg orally four times daily for 7 days 1
  • Amoxicillin: 500 mg orally three times daily for 7 days 1
• Alternative regimens:
  • Azithromycin: 1 g orally in a single dose 1
  • Erythromycin base: 250 mg orally four times daily for 14 days 1
  • Erythromycin ethylsuccinate: 800 mg orally four times daily for 7 days 1
  • Erythromycin ethylsuccinate: 400 mg orally four times daily for 14 days 1

Note: Erythromycin estolate is contraindicated during pregnancy due to hepatotoxicity 1

Gonorrhea Treatment

Recommended Regimen

• Ceftriaxone: 125 mg IM in a single dose 1
• Due to increasing resistance patterns, dual therapy is often recommended:
  • Ceftriaxone 125 mg IM in a single dose PLUS
  • Azithromycin 1 g orally in a single dose OR doxycycline 100 mg orally twice daily for 7 days 1

Trichomoniasis Treatment

Recommended Regimen

• Metronidazole: 2 g orally in a single dose 1

Sexual Assault Prophylaxis

Recommended Empiric Regimen

• Ceftriaxone: 125 mg IM in a single dose, PLUS
• Metronidazole: 2 g orally in a single dose, PLUS
• Azithromycin: 1 g orally in a single dose OR doxycycline: 100 mg orally twice daily for 7 days 1

Genital Herpes Treatment

Recommended Regimens

• Valacyclovir: For initial episode, recurrent episodes, or suppressive therapy 4

  • Initial episode: Treatment should be initiated within 72 hours of onset
  • Recurrent episodes: Treatment should be initiated within 24 hours of onset
  • Suppressive therapy: For chronic suppression of recurrent episodes

• Famciclovir: Alternative treatment option 5

  • Recurrent episodes: 1000 mg twice daily for 1 day
  • Suppressive therapy: 250 mg twice daily
  • Herpes zoster: 500 mg every 8 hours for 7 days

Follow-Up and Partner Management

Follow-Up Care

• Patients should return for evaluation if symptoms persist or recur after treatment completion 1
• Symptoms alone without objective signs are not sufficient basis for retreatment 1
• Patients should abstain from sexual intercourse until therapy is completed 1, 2

Partner Management

• All sexual partners from the preceding 60 days should be referred for evaluation, testing, and treatment 1, 2
• The most recent partner should be evaluated and treated even if the last sexual contact was >60 days before symptom onset 1

Treatment Considerations

Persistent or Recurrent Urethritis

Recommended treatment:

• Metronidazole: 2 g orally in a single dose, PLUS
• Erythromycin base: 500 mg orally four times daily for 7 days, OR
• Erythromycin ethylsuccinate: 800 mg orally four times daily for 7 days 1

Compliance Considerations

• Single-dose regimens have important advantages for compliance and directly observed therapy 1, 6, 7
• For patients with questionable compliance, azithromycin should be available and considered 2, 8
• Studies show comparable effectiveness between single-dose azithromycin and 7-day doxycycline regimens when compliance is good 9, 8

Common Pitfalls and Caveats

1. Inadequate partner treatment: Failure to treat partners is a major cause of recurrence 8
2. Incomplete treatment: Not completing the full course of multi-dose regimens can lead to treatment failure
3. Reinfection vs. treatment failure: Distinguish between true treatment failure and reinfection from untreated partners 8
4. Masking syphilis: Antimicrobial agents used for short periods to treat non-gonococcal urethritis may mask or delay symptoms of incubating syphilis 3
5. Pregnancy considerations: Doxycycline and ofloxacin are contraindicated in pregnant women 1

Remember that prompt and appropriate treatment of STDs is essential to prevent complications such as pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain 2.