“Single-Dose Doxy” for prevention is not supported by science or common sense

Here’s the link to Dr Elizabeth Maloney’s paper, Challenge to the Recommendation on the Prophylaxis of Lyme Disease” (PDF).

The “Prophylaxis Recommendation” of the IDSA Guidelines — Recommendation #2 — is poorly supported by its only supporting literature. Moreover, the “Single-Dose Doxy” practise is difficult to implement in a clinical setting; and furthermore, it is, in itself, a bad idea because a small dose of doxycycline can mask the body’s response (make an infection more difficult to detect in future) while also having the effect of leaving a deeper infection undetected where it can bloom into a persistent, chronic establishment.

Recommendation #2 from the IDSA Guidelines

2. For prevention of Lyme disease after a recognized tick bite, routine use of antimicrobial prophylaxis or serologic testing is not recommended (E-III). A single dose of doxycycline may be offered to adult patients (200 mg dose) and to children 8 years of age (4 mg/kg, up to a maximum dose of 200 mg) (B-I) when all of the following circumstances exist: (a) the attached tick can be reliably identified as an adult or nymphal I. scapularis tick that is estimated to have been attached for 36 h on the basis of the degree of engorgement of the tick with blood or on certainty about the time of exposure to the tick, (b) prophylaxis can be started within 72 h of the time that the tick was removed, (c) ecologic information indicates that the local rate of infection of these ticks with B. burgdorferi is 20%, and (d) doxycycline is not contraindicated.

This recommendation is based on a flawed study by Nadelman et al., Prophylaxis with single-dose doxycycline for the prevention of Lyme disease after an Ixodes scapularis tick bite, published in The New England Journal of Medicine in 2001.

And here’s another interesting E. Maloney link …

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