Which antibiotics should be prescribed if a tick bites? - briefly
A single 200 mg dose of doxycycline administered within 72 hours of an Ixodes tick bite is the preferred prophylactic antibiotic; if doxycycline is contraindicated, a 5‑day regimen of amoxicillin (or cefuroxime) is recommended.
Which antibiotics should be prescribed if a tick bites? - in detail
After a tick attachment, antibiotic selection depends on the risk of Lyme disease and other tick‑borne infections, the duration of attachment, patient age, pregnancy status, and local pathogen prevalence.
A single oral dose of doxycycline (100 mg) given within 72 hours of tick removal is recommended for prophylaxis when the following criteria are met: the tick is identified as Ixodes species, it has been attached for ≥36 hours, the local incidence of Lyme disease exceeds 20 cases per 100,000 population, and the patient has no contraindication to tetracyclines. This regimen reduces the likelihood of early infection by approximately 80 %.
When doxycycline is unsuitable—such as in children younger than eight years, pregnant or lactating women—amoxicillin (2 g orally, single dose) serves as an alternative. For patients with a documented allergy to penicillins, cefuroxime axetil (1 g orally, single dose) may be used.
If an early localized or disseminated infection is diagnosed, a full therapeutic course is required rather than a single prophylactic dose. Standard regimens include:
- Doxycycline 100 mg twice daily for 10–14 days (adults and children ≥8 years).
- Amoxicillin 500 mg three times daily for 14 days (children, pregnant, or lactating patients).
- Cefuroxime axetil 250 mg twice daily for 14 days (penicillin‑allergic individuals).
For anaplasmosis or ehrlichiosis, doxycycline remains the drug of choice, administered at 100 mg twice daily for 10 days (or 5 days in uncomplicated cases). Babesiosis requires antiprotozoal therapy and is not treated with antibiotics.
Key considerations:
- Verify tick species and attachment time before initiating prophylaxis.
- Assess patient medical history for contraindications to tetracyclines or β‑lactams.
- Educate patients on signs of evolving infection—fever, erythema migrans, arthralgia, neurological symptoms—and advise prompt medical evaluation if they develop.
- Document the prophylactic dose and provide written instructions for follow‑up, especially for high‑risk groups.
These guidelines align with current recommendations from the Infectious Diseases Society of America and the Centers for Disease Control and Prevention.