Which antibiotics should be taken for a tick bite? - briefly
Doxycycline 100 mg taken orally twice daily for 10–14 days is the first‑line treatment for a tick bite. If doxycycline is contraindicated, amoxicillin 500 mg three times daily for the same duration is an accepted alternative.
Which antibiotics should be taken for a tick bite? - in detail
Doxycycline is the first‑line agent for preventing infection after a confirmed or suspected bite from a tick that carries Borrelia burgdorferi. The recommended regimen is 100 mg orally once daily for 21 days, started within 72 hours of removal. For children weighing less than 45 kg, the dose is 4 mg/kg (maximum 100 mg) once daily for the same duration.
If doxycycline is contraindicated—such as in pregnancy, lactation, or known hypersensitivity—alternative options include:
- Amoxicillin: 500 mg orally three times daily for 21 days (or 20 mg/kg three times daily in children).
- Cefuroxime axetil: 500 mg orally twice daily for 21 days (or 30 mg/kg twice daily in children).
These alternatives are effective for early Lyme disease but lack activity against Anaplasma and Rickettsia species, which doxycycline covers.
When the bite is associated with signs of other tick‑borne illnesses (e.g., fever, rash, myalgia), doxycycline remains the drug of choice because it treats Lyme disease, ehrlichiosis, anaplasmosis, and Rocky Mountain spotted fever in a single regimen.
For prophylaxis against tick‑borne bacterial infections other than Lyme disease, no universally accepted short‑course regimen exists. Clinical judgment should guide therapy based on local epidemiology, symptom onset, and laboratory confirmation.
Key considerations when prescribing:
- Initiate therapy promptly; delay beyond 72 hours reduces prophylactic efficacy for Lyme disease.
- Verify patient’s ability to swallow tablets; pediatric formulations are available in liquid form.
- Monitor for gastrointestinal upset, photosensitivity, and rare esophageal irritation with doxycycline; advise patients to take the medication with food and remain upright for 30 minutes.
- Counsel pregnant or lactating women on the safety profile of amoxicillin and cefuroxime, emphasizing that doxycycline is contraindicated in these groups.
In cases of confirmed infection rather than prophylaxis, the same agents are used, but treatment duration may extend to 14–28 days depending on disease manifestation and severity, following established clinical guidelines.