What is the recommended dose and duration of minocycline (tetracycline antibiotic) for treating skin infections?

Minocycline Dosing for Skin Infections

For skin infections, minocycline should be administered at 100 mg twice daily for adults, with a treatment duration of 7-14 days. 1, 2

Recommended Dosing Regimens

Adults:

• Initial dose: 200 mg loading dose, then 100 mg every 12 hours 1
• Standard maintenance dose: 100 mg twice daily 1, 2
• Duration for skin and soft tissue infections: 7-14 days 1

Children:

• Not recommended for children under 8 years of age due to risk of permanent tooth discoloration and enamel hypoplasia 2
• For children ≥8 years:
  • <45 kg: 2 mg/kg/dose every 12 hours 1

  • 45 kg: adult dose (100 mg twice daily) 1

Clinical Applications for Skin Infections

Outpatient Treatment:

• Minocycline is effective for outpatient management of skin and soft tissue infections (SSTIs), particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA) 1
• It is considered an alternative to other oral agents such as trimethoprim-sulfamethoxazole, doxycycline, and clindamycin 1

Inpatient Treatment:

• For more severe infections requiring hospitalization, parenteral agents like vancomycin are preferred initially 1
• Transition to oral minocycline may be considered upon clinical improvement 1

Efficacy Considerations

• Minocycline has both antimicrobial and anti-inflammatory properties, making it effective for various skin infections 3
• It demonstrates good tissue penetration due to its lipophilic properties 3
• Serum levels achieved with the standard dosing regimen exceed the minimum inhibitory concentration (MIC) for susceptible organisms 4

Safety and Monitoring

• Common side effects include gastrointestinal symptoms (nausea, vomiting, diarrhea) and vestibular disturbances (dizziness, vertigo) 2, 5
• Less common but serious adverse effects include:
  • Hypersensitivity reactions 2
  • Autoimmune disorders (drug-induced lupus, autoimmune hepatitis) 2
  • Skin pigmentation with long-term use (typically with cumulative doses >70g) 5
• Monitoring recommendations:
  • Baseline liver function tests before initiating therapy 2
  • Clinical monitoring for vestibular symptoms 5, 6

Special Considerations

• Pregnancy and breastfeeding: Contraindicated 2
• Renal impairment: No dosage adjustment required, but monitor for adverse effects 2
• Hepatic impairment: Use with caution; monitor liver function 2
• Photosensitivity: Less photosensitizing potential compared to other tetracyclines, but patients should still avoid direct sun exposure 2, 6

Comparative Efficacy

• Minocycline is comparable in efficacy to other tetracyclines for skin infections 3
• It may have advantages over other tetracyclines in certain cases due to:
  • Excellent tissue penetration 3
  • Longer half-life allowing twice-daily dosing 6
  • Activity against some tetracycline-resistant staphylococci 6

Common Pitfalls

• Prescribing for children under 8 years of age (contraindicated) 2
• Inadequate duration of therapy (should be at least 7 days) 1
• Failure to warn patients about vestibular side effects, which can occur early in treatment 5, 6
• Not considering drug interactions with antacids, iron supplements, or calcium, which can reduce absorption 2