Lyme Disease

Doses are oral and for adults unless otherwise stated. Visit the Health Products Regulatory Board website or the printed Irish Medicines Formulary for drug SPCs, dosage, contraindications, interactions, or IMF/BNF/BNFC/MIMS. See guidance on dosing in children for quick reference dosage/weight guide.

Letters indicate strength of evidence range from A+ (systematic review) to D (informal opinion). Statins can interact with some antibiotics and increase the risk of rhabdomyolysis. Amiodarone and drugs which prolong the QT interval can interact with many antibiotics. Many antibiotics increase the risk of bleeding with anticoagulants. Please refer to our Drug Interactions Table for further information.

Comments from the Expert Advisory Committee

  • Testing for Lyme disease should only be performed by an accredited laboratory that use validated tests and participate in a formal external quality assurance programme.
  • Laboratory tests are necessary to confirm a diagnosis of later stage infection. Antibodies to B. burgdorferi are usually detectable within 4-8 weeks of infection. Patients with late-stage infection are rarely seronegative and usually have very strongly positive antibody tests.
  • The occurrence of false-positive tests in patients with other infections or conditions such as autoimmune diseases, can lead to misdiagnosis and inappropriate treatment. Other specialised investigations may be necessary for confirmation of a positive result.
  • Symptoms of Lyme disease may take months or years to resolve even after treatment for several reasons, including alternative diagnoses, reinfection, treatment failure, immune reaction, and organ damage caused by Lyme disease.


Early onset / erythema migrans without evidence of neurological or cardiac manifestations:

  • Early onset is a Clinical diagnosis – presence of ‘bull’s eye’ skin lesion and assessment of tick exposure risk
  • Diagnose Lyme disease in people with erythema migrans -a red rash that increases in size and may sometimes have a central clearing.
  • It is not usually itchy, hot, or painful. It becomes visible from one to four weeks (but can appear from 3 days to 3 months) after a tick bite and lasts for several weeks at the site of a tick bite.
  • Be aware that a rash that is not erythema migrans can develop as a reaction to a tick bite. This rash usually develops and recedes within 48 hours from the time of the tick bite
  • No laboratory test required

Lymedisease, erythema migrans’     image for treatment Lyme disease

Image: erythema migrans

Post exposure prophylaxis:

If tick remains on the skin, carefully remove it. Link to instructions

Antibiotic prophylaxis generally not indicated unless all the following criteria are fulfilled:

  • Tick bite occurred in endemic area
  • Tick has been identified as Ixodes species
  • Tick is estimated to have been attached for ≥36 hours
  • If 72 or more hours has elapsed since tick removal , prophylaxis is not effective and should not be given
  • Doxycycline not contraindicated

Doxycycline 200mg PO single dose

Alternative: none

Later stage infection:

 Post-Lyme disease syndrome:

  • Antibiotics not recommended where Lyme disease has previously been adequately treated – no demonstrable clinical benefit from prolonged antibiotic therapy
  • Supportive management, .e.g. for management of chronic pain, fatigue, depression
Reviewed September 2018