What is the recommended prophylaxis for Lyme disease?

From the Guidelines

Lyme prophylaxis should be given as a single 200mg dose of doxycycline within 72 hours of tick removal when specific criteria are met, as recommended by the Infectious Diseases Society of America (IDSA) in their 2020 guidelines 1. This preventive treatment is appropriate when the attached tick is identified as an Ixodes (deer) tick that has been attached for at least 36 hours, and when the local rate of infection of ticks with Borrelia burgdorferi is at least 20% 1. Some key points to consider when deciding on Lyme prophylaxis include:

• The tick species and stage, with Ixodes scapularis ticks being the primary vector for Lyme disease in the US 1
• The duration of tick attachment, with ticks attached for 36 hours or more posing a higher risk of transmission 1
• The local rate of infection of ticks with B. burgdorferi, with areas having an infection rate of 20% or higher being considered high-risk 1
• The use of doxycycline as the preferred antibiotic for prophylaxis, due to its efficacy and safety profile 1
• The importance of prompt removal of attached ticks, as this can help prevent transmission of B. burgdorferi 1 It is also important to note that doxycycline should not be used in children under 8 years old or pregnant women due to risks of dental staining and effects on fetal development; in these cases, careful observation for symptoms is recommended instead 1. If a patient develops symptoms such as erythema migrans (bull's-eye rash), fever, or joint pain after a tick bite despite prophylaxis, they should seek medical attention for full treatment of Lyme disease 1. Prophylaxis is not recommended for other tick-borne diseases or for bites from other tick species 1.

From the FDA Drug Label

For the prophylaxis of malaria: For adults, the recommended dose is 100 mg daily. The FDA drug label does not answer the question about Lyme prophylaxis.

From the Research

Lyme Prophylaxis

• The use of a single dose of doxycycline after a tick bite can prevent the development of Lyme borreliosis in North America and Europe 2, 3, 4.
• A study conducted in Europe found that a single dose of 200mg doxycycline within 72 hours after removing an attached tick from the skin resulted in a relative risk reduction of 67% and a number-needed-to-treat of 51 2.
• In the United States, residents of the coastal Northeast, northwest California, and the Great Lakes region are at highest risk of contracting Lyme disease, and children and those spending extended time outdoors in wooded areas are also at increased risk 3.
• Prophylactic antibiotic treatment of tick bites by Ixodes scapularis in Lyme disease hyperendemic regions can be effective in preventing infection with Borrelia burgdorferi sensu stricto, the Lyme disease spirochete 5, 4.
• An animal model study found that two treatments of doxycycline delivered by oral gavage to mice on the day of removal of a single potentially infectious nymphal I. scapularis protected 74% of test mice compared to controls, but prophylactic treatment was totally ineffective when delivered ≥2 days after tick removal 5.
• A randomized, double-blind, placebo-controlled trial of treatment with a single 200-mg dose of doxycycline in 482 subjects who had removed attached I. scapularis ticks from their bodies within the previous 72 hours found that the efficacy of treatment was 87% 4.
• Pharmacist initiation of postexposure doxycycline for Lyme disease prophylaxis has been shown to be effective in preventing the development of Lyme disease, with high patient satisfaction and no reports of serious adverse events 6.