Abstract
BACKGROUND: Myalgic encephalomyelitis (ME) is associated with long COVID and also untoward sequelae after anti-coronavirus vaccination. Recently, oral minocycline therapy has been reported to ameliorate symptoms in patients with ME, particularly at the initial stage of the disease. METHODS: Oral minocycline (100 mg × 2 on the first day, followed by 100 mg/day for 41 days) was administered to 55 patients with ME that emerged during the "Corona era," including 19 patients with long COVID and 5 patients diagnosed with untoward sequalae following coronavirus vaccination. RESULTS: Acute adverse effects including nausea and/or dizziness caused four (7 %) patients to discontinue treatment in the first few days. Among the other 51 patients who completed therapy, favorable effects were observed, including a decrease in performance status score or index for restricted activities of daily living ≥2 points in 41 (80 %) patients. Disease duration was inversely associated with the favorable therapeutic effects (p = 0.02) and the disease duration within 6 months was significantly associated with the favorable therapeutic effects (27/30, 90 %, p = 0.02, hazard ratio: 3.6, 95 % confidence interval, 1.2-10.6). The favorable effects were observed in 16 (89 %) of 18 patients with long COVID. Significant amelioration of subjective symptoms of fatigue, post-exertional malaise, unrefreshing sleep, brain fog, disequilibrium, orthostatic intolerance, and neuropathic pain were observed. CONCLUSIONS: Oral minocycline was effective at ameliorating symptoms in patients with ME including long COVID and post-coronavirus vaccination sequalae. It represents an effective first-line therapeutic option for these patients in the initial stage.