Tafenoquine for Relapsing Babesia: A Treatment Option When Standard Therapy Fails
Tafenoquine Babesia treatment may offer hope for patients who relapse after standard therapy. In this case, a 36-year-old man was hospitalized in 2019 after experiencing unexplained fevers for two weeks. He was later diagnosed with Babesia infection, with 8.5% of his red blood cells infected with the parasite.
The patient had previously been diagnosed with granulomatosis with polyangiitis in 2001 and was considered immunocompromised following treatment two years earlier with rituximab, a monoclonal antibody used in immunotherapy. He had also received methotrexate, cyclophosphamide, and steroids.
Initial Babesia Treatment and First Relapse
The man’s initial Babesia treatment included atovaquone and azithromycin for 10 days. The atovaquone dose was 750 mg once daily instead of the standard twice-daily dosing.
Two months later he relapsed. His blood smear was again positive. He was treated with azithromycin plus atovaquone for 12 weeks with clearing of the parasite.
Second and Third Babesia Relapses
Two months later he experienced a second relapse. Atovaquone plus azithromycin were again prescribed for an additional 45 days. Clindamycin was added for two weeks because of a persistent positive blood smear for Babesia.
Two months later he had a third relapse. “A blood sample was tested for genetic evidence of drug resistance to either azithromycin or atovaquone, and at least partial resistance to both drugs was found,” the authors reported.
This pattern of repeated relapse is common in patients with chronic Babesia, particularly those who are immunocompromised.
Four-Drug Therapy Before Tafenoquine Babesia Treatment
The physicians then switched to a four-drug regimen.
“Therefore, on 1/29/20 the patient was started on a malarone®-based four drug regimen that included high-dose azithromycin at 1000 mg per day, plus clindamycin orally at 450 mg three times per day, plus a 750 mg dose of atovaquone in addition to the atovaquone received as part of malarone® therapy,” according to the authors.
The patient, however, remained ill and was eventually started on a six-week regimen of tafenoquine alone.
Why Tafenoquine May Help Relapsing Babesia
Tafenoquine is an 8-aminoquinoline and a primaquine analogue that received United States Food and Drug Administration approval in 2018 for malaria prophylaxis and prevention of relapse of Plasmodium vivax malaria. Tafenoquine is marketed as Krintafel in the United States.
Note: In animal models, tafenoquine has been shown to rapidly clear Babesia microti parasites.
Before prescribing tafenoquine, clinicians confirmed that the patient did not have a psychiatric history, glucose-6-phosphate dehydrogenase (G6PD) deficiency, or QT interval abnormalities.
The patient responded well to therapy. However, investigators could not determine whether the improvement resulted from tafenoquine alone or the weeks of treatment preceding it.
Experimental studies in hamsters and highly immunocompromised mice have demonstrated that tafenoquine can rapidly clear Babesia microti parasites.
Implications for Immunocompromised Patients
The authors concluded that tafenoquine may be particularly valuable for highly immunocompromised patients with babesiosis who often require extended treatment courses lasting six weeks or longer.
This observation aligns with what we see in patients with asplenia, who frequently require longer Babesia treatment durations.
Editor’s note: The authors did not discuss the possibility that the patient might have had Babesia duncani, which was originally identified on the West Coast but is now found in the eastern United States as well. Babesia duncani infections can be particularly difficult to treat.
Frequently Asked Questions About Tafenoquine Babesia Treatment
What is tafenoquine?
Tafenoquine is an antimalarial drug approved in 2018 that has shown promise for treating relapsing Babesia infections.
When is tafenoquine used for Babesia?
It may be considered in patients who relapse after treatment with atovaquone and azithromycin, particularly immunocompromised individuals.
Can Babesia become resistant to treatment?
Yes. This case demonstrated partial resistance to both azithromycin and atovaquone after multiple relapses.
Who should not take tafenoquine?
Patients with G6PD deficiency, certain psychiatric conditions, or QT interval abnormalities should be carefully evaluated before starting tafenoquine.
How long is tafenoquine used for Babesia?
In this case, a six-week course was used. Immunocompromised patients often require treatment for at least six weeks and sometimes longer.
References
- Marcos LA, Leung A, Kirkman L, Wormser GP. Use of tafenoquine to treat a patient with relapsing babesiosis with clinical and molecular evidence of resistance to azithromycin and atovaquone. IDCases. 2022;27:e01460.
Tested positive to B. Duncani multiple times, treated with many different AB, including ATovaquone, Malarone, for over a year, they symptoms come back as when I go off AB, and only partially resove when on them, I gave up.
There seems to be no protocol on treating Lyme & Babesia or real diagnostic tool to know what I we are suffering from, a bunch of guessing and very expensive too. The LLMD medicine is really a guessing game with a bunch of AB. & herbs / vitamins based on hearsay, also copy and paste of what the famous Dr. Horowitz or Dr. Jemsek may have speculated sometime in the past. LLMD’s are hesitant to go all in on IVIG or intv. AB, leave it up to the patient to run around to convince someone to treat them. They dont even know when to stop, usually ends when the patient has spent all they got and are coming to term with the pain.
Primary care physicians I have seen say it’s one of the following herniated disk, fibro myalgia, sleep apnea, stress, pre diabetic, and when I developed all of this in such a short period of time, I am told we dont know (or dont care)
I have given up hope.
Joel,
Most of us have the same issue with PC.
I can’t even get them to test for other issues. I begged for years and finally got 2 additional tests when I tested positive for qfever. Then the PC said he didn’t know what to do with the results.
Contacted the health department and they referred me back to the same pc.
Of the several people I know with Babesia duncani (including myself) NOT ONE has been able to eradicate it with any combination of drugs and/or herbs.
I think most anti Protozoa drugs are anti cancer drugs when you can benefit from an unfettered search on internet ( as I can from overseas) and dig about forty pages of repeated material ( yawn) in. I’m so glad you’re feeling better. Babesia has something to teach us all quite obviously. My homeopath doctor in Brasilia also uses magnetic resonance and is quite genius. It’s great you study this and are inspired by your recovery.
I am currently using this to treat a very persistent case of Babesia, and I am immune- compromised. What dose did this person take for six weeks?
“3/10/20 he was started on a 6 week regimen of tafenoquine aloneThe dose was 200 mg daily for three consecutive days and then 200 mg per week, i.e., the regimen FDA approved for malaria prophylaxis” wrote the Marcos LA, etc You can read the article on pubmed at https://pmc.ncbi.nlm.nih.gov/articles/PMC8885462/
Is this treatment successful for patients with additional infections symptoms ch as bartonella, Lyme and Rocky Mtn Spotted Fever?
No
I have been on tafenoquine 200mg weekly for 2 years for chronic babesiosis and I do think it worked well for me.
However my son was treated with the same regimen along with atovaquone for 8 months. For acute babesia duncani the dosage should be prescribed differently.
Thank you for sharing your experience. Treatment decisions, including medication choice, dose, and duration, need to be individualized and guided by a treating clinician. I can’t comment on specific regimens in comments.