From the Guidelines
Single-dose treatment for Lyme disease is only recommended for prophylaxis after a high-risk tick bite, not for established infection. For patients who have been bitten by a high-risk Ixodes spp. tick, a single dose of oral doxycycline within 72 hours of tick removal is recommended for chemoprophylaxis 1. The dose is 200 mg for adults and 4.4 mg/kg (up to a maximum dose of 200 mg) for children. However, for established Lyme disease infection, single-dose antibiotic therapy is insufficient to eradicate Borrelia burgdorferi, the bacterium causing Lyme disease, which requires a longer course of treatment to prevent progression to later stages of the disease. Some key points to consider when deciding on a treatment plan include:
- The standard treatment for early localized Lyme disease (Stage 1) is doxycycline 100 mg orally twice daily for 10-14 days.
- For patients who cannot take doxycycline (such as pregnant women or children under 8 years), alternatives include amoxicillin 500 mg three times daily for 14-21 days or cefuroxime axetil 500 mg twice daily for 14-21 days.
- The bacterium can persist in tissues and evade the immune system, necessitating sustained antibiotic levels over multiple days. The most recent and highest quality study on this topic is from 2021, which provides guidance on the prevention, diagnosis, and treatment of Lyme disease 1.
From the Research
Single-Dose Lyme Disease Treatment
- The use of a single dose of doxycycline as a treatment for Lyme disease has been studied in several research papers 2, 3, 4, 5, 6.
- A study published in the Mayo Clinic proceedings in 2008 found that single-dose doxycycline (200 mg orally) can be used as prophylaxis in selected patients 2.
- Another study published in BMC infectious diseases in 2021 found that the pooled rate of unfavorable events in persons receiving single-dose 200-mg doxycycline was 0.4% (95%CI: 0.1-1.1%) compared to 2.2% (95%CI: 1.6-3.0%) in the control group, with a pooled risk ratio of 0.29 (95%CI: 0.14-0.60) 3.
- A randomized controlled trial published in The Journal of infection in 2021 found that a single dose of doxycycline after an Ixodes ricinus tick bite can prevent the development of Lyme borreliosis, with a relative risk reduction of 67% (95% CI 31 - 84%) 4.
- A study published in The New England journal of medicine in 2001 found that a single 200-mg dose of doxycycline given within 72 hours after an I. scapularis tick bite can prevent the development of Lyme disease, with an efficacy of 87 percent (95 percent confidence interval, 25 to 98 percent) 6.
Efficacy and Safety
- The efficacy of single-dose doxycycline in preventing Lyme disease has been demonstrated in several studies, with risk reductions ranging from 67% to 87% 3, 4, 6.
- The safety of single-dose doxycycline has also been evaluated, with some studies reporting more frequent adverse effects, such as nausea and vomiting, compared to placebo 3, 6.
- However, no serious adverse events were reported in a study published in The Journal of infection in 2021 4.
Clinical Applications
- Single-dose doxycycline may be considered as a prophylactic treatment for individuals who have been bitten by a tick in areas where Lyme disease is endemic 2, 3, 4, 6.
- The use of single-dose doxycycline may be particularly useful in preventing the development of Lyme disease in individuals who are at high risk of infection, such as those who have been bitten by a nymphal tick that is at least partially engorged with blood 6.