Which tablets should be taken when bitten by a tick? - briefly
Doxycycline, 100 mg taken once daily for 10–14 days, is the first‑line oral medication to prevent Lyme disease after a tick bite. If doxycycline is contraindicated, alternatives such as amoxicillin or cefuroxime may be used under medical supervision.
Which tablets should be taken when bitten by a tick? - in detail
After a tick attachment, immediate removal reduces infection risk, but pharmacologic prophylaxis is often recommended when certain criteria are met: the tick is identified as a likely carrier of Borrelia burgdorferi, it has been attached for at least 36 hours, prophylaxis can begin within 72 hours of the bite, and the local incidence of Lyme disease exceeds 20 cases per 100 000 people.
First‑line oral antibiotic
- Doxycycline 100 mg once daily for 21 days (adults).
- Preferred for adults and children ≥8 years.
- Effective against Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, and anaplasmosis.
- Contraindicated in pregnancy, lactation, and children <8 years because of teeth staining.
Alternative agents
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Amoxicillin 500 mg three times daily for 21 days (adults).
- Suitable for pregnant or nursing women and children <8 years.
- Does not cover rickettsial infections; use only when Lyme disease is the sole concern.
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Cefuroxime axetil 250 mg twice daily for 21 days (adults).
- Alternative for patients intolerant to doxycycline or amoxicillin.
- Similar spectrum to amoxicillin for Borrelia.
Treatment of confirmed infection
- Early localized Lyme disease – doxycycline 100 mg twice daily for 14–21 days, or amoxicillin 500 mg three times daily for the same duration.
- Neurologic or cardiac involvement – intravenous ceftriaxone 2 g daily for 14–28 days.
- Babesiosis – atovaquone 750 mg with azithromycin 500 mg daily for 7–10 days.
- Rocky Mountain spotted fever – doxycycline 100 mg twice daily for 7–14 days, regardless of age.
Pediatric dosing
- Doxycycline 2.2 mg/kg (maximum 100 mg) twice daily.
- Amoxicillin 50 mg/kg/day divided three times.
- Cefuroxime 30 mg/kg/day divided twice.
Key considerations
- Verify allergy history before selecting an agent.
- Ensure adherence to the full course; incomplete treatment increases risk of chronic manifestations.
- Monitor for adverse effects: gastrointestinal upset with doxycycline, rash with amoxicillin, and liver function changes with ceftriaxone.
- Seek medical evaluation if fever, expanding rash, joint pain, or neurological symptoms develop despite prophylaxis.