Which drugs are injected after a tick bite? - briefly
After a tick bite, a single dose of doxycycline (or amoxicillin for children and doxycycline‑allergic patients) is given as prophylaxis against Lyme disease, and tetanus toxoid may be administered if the victim’s immunization status is uncertain. Additional antibiotics are prescribed only if an infection becomes apparent.
Which drugs are injected after a tick bite? - in detail
After a tick attaches, clinicians consider immediate pharmacologic interventions to prevent infection. The choice depends on the tick species, geographic region, duration of attachment, and patient risk factors.
Antibiotic prophylaxis for Lyme disease
- Doxycycline 200 mg orally, single dose, administered within 72 hours of removal when the tick is identified as Ixodes scapularis or Ixodes pacificus, the attachment lasted ≥36 hours, and the local incidence of Lyme disease exceeds 20 cases per 100,000.
- Contraindications: pregnancy, children < 8 years, severe hepatic impairment. Alternative: amoxicillin 500 mg orally, single dose, for patients unable to take doxycycline.
Rickettsial infection prevention
- Doxycycline 200 mg orally, single dose, recommended when the bite occurs in areas endemic for spotted fever group rickettsioses and the tick is identified as Dermacentor spp.
- For severe allergy to tetracyclines, chloramphenicol 500 mg orally, single dose, may be used.
Anaplasmosis and Ehrlichiosis
- Doxycycline 100 mg orally twice daily for 10–14 days, initiated promptly after diagnosis; prophylactic single dose is not standard, but early treatment is advised if symptoms appear.
Babesiosis
- No prophylactic drug is endorsed; treatment begins after laboratory confirmation, typically atovaquone 750 mg plus azithromycin 500 mg orally twice daily for 7–10 days.
Tick-borne viral infections (e.g., Powassan virus)
- No specific antiviral therapy; supportive care is provided. No prophylactic injection is recommended.
Adjunctive measures
- Tetanus toxoid booster if the patient’s immunization status is uncertain and the bite is contaminated.
- Pain relief with non‑opioid analgesics; no steroid injection is indicated.
These regimens represent the current standard of care for pharmacologic management following a tick bite. Prompt assessment of tick identification, exposure risk, and patient health status guides the appropriate choice and timing of medication.