What are the alternatives to doxycycline (Doxycycline) for the treatment of Sexually Transmitted Infections (STIs)?

Alternatives to Doxycycline for STI Treatment

Azithromycin is the primary alternative to doxycycline for most STIs, with erythromycin, ofloxacin, and levofloxacin serving as additional options when both first-line treatments are contraindicated. 1

First-Line Alternatives

Azithromycin

• Dosage: 1g orally in a single dose
• Advantages:
  • Single-dose administration improves compliance
  • Directly observed therapy possible
  • Particularly useful for patients with poor adherence to multi-day regimens
• Efficacy: Similar to doxycycline for chlamydial infections (97% vs 98% cure rates) 1
• Caution: Declining efficacy against Mycoplasma genitalium (from 85.3% before 2009 to 67% since 2009) 1, 2

Second-Line Alternatives

When both doxycycline and azithromycin are contraindicated:

Erythromycin

• Dosage options:
  • Erythromycin base: 500 mg orally four times daily for 7 days
  • Erythromycin ethylsuccinate: 800 mg orally four times daily for 7 days
• Limitations:
  • Less efficacious than doxycycline or azithromycin
  • Frequent gastrointestinal side effects reduce compliance 1
• Best use: Pregnancy when azithromycin is not an option

Fluoroquinolones

• Options:
  • Ofloxacin: 300 mg orally twice daily for 7 days
  • Levofloxacin: 500 mg orally once daily for 7 days
• Limitations:
  • More expensive than other options
  • No dosing advantage over doxycycline
  • Not reliably effective against all chlamydial infections 1

Special Populations

Pregnant Women

1. Azithromycin: 1g orally in a single dose (preferred)
2. Erythromycin: If azithromycin is contraindicated
3. Doxycycline: Contraindicated in pregnancy 1, 2

Patients with Poor Medication Adherence

• Azithromycin is strongly preferred due to single-dose administration 1, 2

STI-Specific Alternatives

For Gonococcal Infections

• Ceftriaxone (intramuscular or intravenous)
• Cefixime (oral) 1

For Syphilis

• Benzylpenicillin in various formulations depending on the stage of infection 1

Implementation Considerations

1. Maximize compliance:

   • Dispense medication on-site when possible
   • Directly observe first dose
   • Instruct patients to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of multi-day regimen 1

2. Follow-up:

   • Test-of-cure generally not recommended except in pregnancy
   • Wait at least 3-4 weeks after treatment completion if follow-up testing is needed 1

Pitfalls to Avoid

• Inadequate partner treatment: Ensure all sexual partners from the previous 60 days are evaluated and treated 1
• Reinfection risk: Advise abstinence until all partners are treated 1
• Premature retesting: False-positive results may occur if testing is done <3 weeks after treatment completion due to dead organisms 1
• Overlooking coinfections: Test for other STIs, including HIV and syphilis 1

The choice between alternatives should be guided by patient-specific factors including pregnancy status, likelihood of adherence, cost considerations, and local resistance patterns.