A groundbreaking in vivo clinical study conducted by Dr. Richard Horowitz has found that an eight-week course of the leprosy drug dapsone combined with doxycycline and rifampin is effective in improving symptoms in 98% of patients suffering from chronic Lyme disease/Post Treatment Lyme Disease Syndrome (PTLDS).
https://www.lymedisease.org/horowitz-dapsone-chronic-lyme/Study
https://www.mdpi.com/2079-6382/9/11/725