Chronic Lyme Disease Remission With Low-Dose Flagyl: Case Report
BETTER ON ANTIBIOTICS—THEN RELAPSING?
SYMPTOMS KEEP COMING BACK?
CAN LOW-DOSE TREATMENT MAINTAIN REMISSION?
Low-dose Flagyl (metronidazole) for Lyme disease was associated with sustained remission in a patient with chronic, relapsing symptoms after years of illness.
“I improved with treatment—but the symptoms kept coming back.”
This case highlights a common pattern seen in persistent Lyme disease symptoms—initial improvement with antibiotics followed by recurrent relapses.
A Complex and Debilitating Illness
A 55-year-old man developed progressive neurologic and systemic symptoms, including:
- Numbness and burning in the legs and hands
- Tinnitus
- Severe fatigue and weakness
- Muscle pain and nighttime cramps
- Palpitations and shortness of breath
- Orthostatic hypotension
His fatigue was described as intense and incapacitating, accompanied by anxiety, brain fog, difficulty concentrating, and sleep disturbance,
according to the authors.
He recalled a prior tick bite but did not report a rash.
Misdiagnosis and Delayed Recognition
Despite extensive evaluation—including MRI, CT scans, and blood work—results were normal.
He was initially diagnosed with diabetic neuropathy and treated with analgesics and duloxetine, without improvement.
His symptoms progressed to include:
- Tinnitus linked to neuropathy
- Urinary dysfunction
- Erectile dysfunction
These findings reflect patterns often seen in
Lyme disease misdiagnosis, where neurologic symptoms are attributed to other conditions.
Diagnosis and Initial Treatment
The patient was eventually diagnosed in France with
polymorphic persistent syndrome after a possible tick bite (SPPT), a condition similar to post-treatment Lyme disease.
He received multiple therapies including:
- Doxycycline
- Ceftriaxone
- Hydroxychloroquine
- Metronidazole
Following treatment, most symptoms resolved except for intermittent leg pain.
Relapsing Pattern After Treatment
After undergoing chemotherapy for lung cancer, the patient experienced a recurrence of Lyme-related symptoms.
Relapses occurred every 2–3 months and responded to antibiotics such as doxycycline or azithromycin.
This pattern—improvement with treatment followed by relapse—is common in patients with
persistent Lyme disease.
Low-Dose Flagyl for Maintenance
Due to repeated relapses, clinicians initiated long-term low-dose therapy:
Metronidazole (Flagyl) 500 mg once weekly
The goal was to maintain remission with minimal antibiotic exposure.
Over the following year, the patient remained in complete remission with no recurrence of symptoms.
What This Case Suggests
The authors noted:
- Low-dose antibiotic therapy maintained long-term remission
- The patient returned to normal daily activities and work
- Symptoms repeatedly responded to antibiotic reintroduction
They concluded that this case supports the possibility of a chronic, relapsing form of Lyme disease in some patients.
Clinical Perspective
This case highlights several important clinical themes:
- Persistent symptoms may follow an initial infection
- Relapsing patterns can occur over years
- Response to antibiotics may vary significantly between patients
At the same time, findings from a single case report cannot be generalized to all patients.
Treatment decisions should remain individualized and carefully monitored.
Clinical Takeaway
Low-dose Flagyl was associated with sustained remission in this case of chronic, relapsing Lyme disease.
While not a standard approach, this case illustrates how some patients may respond to tailored, long-term strategies.
Further research is needed to determine which patients may benefit from similar approaches.
Frequently Asked Questions
Can Flagyl treat Lyme disease?
Metronidazole has been used in some cases, but it is not a standard first-line treatment.
Why did this patient relapse?
Relapsing symptoms may reflect complex underlying mechanisms, including persistent infection or immune factors.
Is low-dose antibiotic therapy common?
It is not standard but has been explored in selected cases.
Does this apply to all Lyme patients?
No. This is a single case report and should not be generalized.
References:
- Alexis Lacout, Pierre Yves Marcy, Christian Perronne. Patient with Chronic Lyme Disease and Recurrent Relapses, Maintained in Complete Remission by Low Doses of Metronidazole. Archives of Microbiology and Immunology. 2024.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
Where in the United States can I find a Doctor that will possibly prescribe this medication for my persistent symptoms ? I have seen countless Doctors through many years (many of which seemed clueless or acted as though I was faking my symptoms). Thanks for any replies .
Dr.Daniel Cameron or/and Dr. Richard Horowitz (both are in New York State)
New York State is a long way from where I am located / thanks though .
I hope you find someone closer
Thanks for taking the time to respond to my post . I do wish you were closer although , without a positive test . I am not sure of protocol options . I did test positive for RMSF in 1999 but , that didn’t lead to any futher treatment . The Physician said to me at that time ” I don’t think anymore Antibiotic treatment would be helpful” end quote . Thank you for your time in reading my post .Brian P. Grant . 901-730-0755 729 Forest Lake Drive MPHS , TN. 38117
The tests are not so reliable.
Great article, for how long did they patient take metronidazole?
The case was more complicated on review. The patient also had doxycycline and IV Rocephin before Flagyl. It is more a hypothesis based on one case that would need more study. The duration is unclear. Sorry
There are in vitro studies (in a Petri dish) that show that metronidazole can break down the biofilm that the Lyme bacteria produces to shield itself against conventional antibiotics. There are some that theorize that this biofilm forms in Chronic Lyme disease and that this is what causes it to become antibiotic resistant and chronic. So they theorize that metronidazole may be able to lead to a cure in the body. Of course in vitro studies often do not translate to success in vivo, in the human body, so this is far from being an accepted strategy so far.