How long is doxycycline (antibiotic) treatment for a tick bite?

Doxycycline Treatment Duration for Tick Bites

For tick bite prophylaxis, a single 200 mg dose of doxycycline is the complete recommended treatment when given within 72 hours of tick removal for high-risk bites. 1, 2

Criteria for Prophylactic Treatment

• Prophylactic antibiotic treatment is recommended only when ALL of the following criteria are met:

  • The tick is identified as an Ixodes species (blacklegged tick) 1, 3
  • The tick was attached for ≥36 hours 1, 3
  • The bite occurred in a highly endemic area (≥20% tick infection rates) 1, 3
  • Doxycycline can be administered within 72 hours of tick removal 1, 3
  • Doxycycline is not contraindicated for the patient 1, 3

• If a tick bite cannot be classified with high certainty as high-risk, a wait-and-watch approach is recommended 1, 3

Dosing Information

• For adults: Single oral dose of 200 mg doxycycline 1, 2
• For children ≥8 years: Single oral dose of 4.4 mg/kg (up to maximum 200 mg) 1, 3
• No additional doses are required for prophylaxis 2

Effectiveness

• A single dose of prophylactic doxycycline given within 72 hours after a high-risk tick bite has been shown to be 87% effective in preventing Lyme disease 4
• The efficacy decreases significantly when treatment is delayed beyond 24 hours after tick removal, as demonstrated in animal studies 5

Treatment for Established Lyme Disease

• If erythema migrans (bull's-eye rash) develops, indicating early Lyme disease:
  • Doxycycline: 10-day course 1
  • Amoxicillin or cefuroxime axetil: 14-day course 1
  • Azithromycin (if other antibiotics are contraindicated): 5-10 days (7 days preferred in the US) 1

Post-Treatment Monitoring

• Monitor for symptoms of Lyme disease for 30 days after the tick bite, particularly: 2

  • Expanding skin lesion (erythema migrans) at the bite site
  • Flu-like symptoms (fever, chills, fatigue, body aches, headache)
  • Swollen lymph nodes

• Seek immediate medical attention if any of these symptoms develop 2, 6

Common Pitfalls and Caveats

• Prophylaxis is only effective when administered within 72 hours of tick removal - beyond this window, the effectiveness drops significantly 6, 5
• Testing for Lyme disease is not recommended in asymptomatic individuals following a tick bite, even after receiving prophylaxis 2
• Doxycycline is relatively contraindicated in pregnant women and children <8 years old 3
• Not all tick bites require prophylactic treatment - only those meeting all high-risk criteria 1, 3

Prevention of Future Tick Bites

• Use protective clothing and EPA-registered tick repellents when in tick-endemic areas 2, 3
• Perform daily full-body tick checks 2
• Remove attached ticks promptly using fine-tipped tweezers 2, 3