Lyme disease (borreliosis)

Infection caused by Borrelia burgdorferi, transmitted by Ixodes tick bite. Early stage presents with erythema migrans. Untreated, it can affect joints, nervous system, and heart.

ICD-10 A69.23 drugs

Also known as: Lyme borreliosis, Tick-borne borreliosis

Drugs used for this condition

AAmoxicillinFirst line · Penicillins with extended spectrumFor early Lyme disease with erythema migrans, IDSA/AAN/ACR 2020 recommend Doxycycline, Amoxicillin or Cefuroxime axetil as equal options; Amoxicillin is given 500 mg three times daily for 14 days, in children 50 mg/kg/day in three doses. NICE NG95 (2018) lists Doxycycline first and Amoxicillin as the alternative at 1 g three times daily for 21 days; in pregnant women and children under 9, where Doxycycline is undesirable, Amoxicillin comes first. Amoxicillin is not used for prophylaxis after a tick bite: for high-risk bites a single dose of Doxycycline within 72 hours is used. Neurological, cardiac or joint involvement needs different regimens. The indication is in the Spanish label, which also describes a Jarisch-Herxheimer reaction at the start of Lyme treatment (fever, chills, worsening rash) that resolves on its own. Amoxicillin is contraindicated in penicillin allergy and after anaphylaxis to another beta-lactam; avoid it if infectious mononucleosis is suspected (rash); antibiotic-associated colitis can occur. In pregnancy it is used when benefit outweighs risk; small amounts pass into breast milk. Interactions: Methotrexate (increased toxicity), oral anticoagulants (monitor prothrombin time), Allopurinol (more rash).
ADoxycyclineFirst line · TetracyclinesDrug of choice for Lyme disease per IDSA/AAN/ACR 2020. For early localized disease (erythema migrans), prescribe 100 mg twice daily for 10–21 days. For early disseminated disease without CNS involvement, the same regimen for 14–21 days. Doxycycline is the only oral antibiotic effective in neuroborreliosis without meningitis.

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

FCat's clawNot recommended · Botanical supplement, bark of the Uncaria tomentosa vine (cat's claw, una de gato) from Peruvian and Ecuadorian Amazonia; sold on iHerb for immunity, used in Peru for rheumatic pain and peptic ulcerCat's claw is marketed as a «natural cure for chronic Lyme disease», «cancer treatment without chemotherapy» and «HIV remedy». There is no evidence base for these claims. FTC in 2000, as part of Operation Cure.all, brought legal action against cat's claw manufacturers over cancer and HIV cure claims – the cases were settled in 2000–2001 with bans on such claims. NCCIH (NIH) and IDSA 2020 are unambiguous: in serology-confirmed Lyme disease, standard treatment is doxycycline or amoxicillin for 10–21 days in early disease and up to 28 days in late disease; «chronic Lyme disease» (PTLDS) is a contested diagnosis, and prolonged antibiotic therapy did not work in the STOP-LD and Klempner RCTs, let alone cat's claw. In oncology and HIV, cat's claw does not replace chemotherapy, immunotherapy or antiretroviral therapy – treatment delay reduces survival. If cat's claw was bought instead of prescribed antibiotic therapy, chemotherapy or ART, discuss with a doctor – in these diagnoses, delay of standard treatment costs years of life.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit