Horowitz Dapsone Combination Therapy
Dr. Richard Horowitz's persister protocol (DDDCT / HDDCT)
- Targets
- Lyme, Bartonella, Babesia
- Intensity
- Intensive
- Components
- 4
- Prescription
- Required
Dapsone, a leprosy drug, is combined with other antibiotics and biofilm agents to target persister forms of Lyme and Bartonella. Horowitz reports that double-dose dapsone combination therapy produced remission of a year or longer in about half of patients.
The regimen
Duration: ~8 weeks of double-dose dapsone, sometimes followed by short high-dose pulses
Key points
- Combines dapsone with a cephalosporin/tetracycline, a rifamycin and biofilm agents
- Requires a G6PD test and regular blood counts (risk of anemia and methemoglobinemia)
- A harsh regimen — Dr. Ross notes nearly 40% of patients stop due to side effects
- Published as case series and chart reviews, not yet randomized trials
Example combination
Dr. Ross describes a Horowitz-type regimen of cefuroxime 1,000 mg 2×/day, minocycline 100 mg 2×/day, rifampin 600 mg daily and dapsone 100 mg daily. Horowitz's newer double-dose protocol (DDDCT) raises dapsone to 200 mg daily for 7–8 weeks, sometimes followed by 6–7 day high-dose pulses (HDDCT).
The evidence
- A chart review of 200 patients found dapsone combination therapy reduced the severity of eight major Lyme symptoms (2019).
- Later case series report high rates of improvement and multi-month remissions with double-dose and high-dose pulsed regimens (2022–2024).
See all papers in Research.
Not medical advice. This protocol is summarized from Dr. Richard Horowitz — published case series for educational purposes. Doses are for adults; children need different dosing. Discuss any treatment with a qualified, Lyme-literate clinician, who can monitor labs and adjust for your health and medications.