How should doxycycline be taken after a tick bite in an adult? - briefly
Take 100 mg of doxycycline by mouth twice daily, beginning as soon as possible after the bite, and continue for 10–14 days; ingest the medication with food or a full glass of water to minimize stomach irritation.
How should doxycycline be taken after a tick bite in an adult? - in detail
Doxycycline is the preferred oral antibiotic for preventing early Lyme disease after a confirmed or suspected tick bite in an adult. The recommended regimen is 100 mg taken twice daily for 21 days, beginning as soon as possible—ideally within 72 hours of the bite. Prompt initiation maximizes efficacy in eradicating Borrelia burgdorferi before dissemination.
Administration
- Swallow tablets whole with a full glass of water; do not crush or chew.
- Take each dose with food or a dairy product to reduce gastrointestinal irritation, but avoid taking the medication simultaneously with high‑calcium or iron supplements, as they can impair absorption.
- Maintain at least a two‑hour interval between doxycycline and antacids, calcium, magnesium, or iron preparations.
Monitoring and Side Effects
- Common adverse effects include mild nausea, abdominal discomfort, and photosensitivity. Advise patients to use sunscreen and wear protective clothing when outdoors.
- Rarely, esophageal irritation or ulceration may occur; patients should remain upright for at least 30 minutes after ingestion.
- If severe vomiting, diarrhea, or allergic reaction develops, discontinue the drug and seek medical evaluation.
Contraindications and Precautions
- Avoid use in pregnant or lactating women; an alternative such as amoxicillin is recommended for these groups.
- Assess renal and hepatic function before initiation; dose adjustment is not routinely required in mild impairment but severe dysfunction warrants specialist consultation.
- Review patient medication list for potential interactions, particularly with warfarin, oral contraceptives, and certain antiepileptics, which may require monitoring of therapeutic levels.
Completion of Therapy
- Do not stop treatment early, even if symptoms improve, to prevent relapse or resistance.
- At the end of the 21‑day course, evaluate the patient for any lingering signs of Lyme disease; if erythema migrans or systemic manifestations appear, initiate a full treatment protocol for early disseminated infection.
Adherence to this schedule, combined with appropriate counseling on administration and side‑effect management, provides the most reliable prophylaxis against Lyme disease after a tick encounter in an adult.