Switch effects from daily to intermittent treatment with a daily regimen dosage for Mycobacterium avium complex pulmonary disease

<b>Background:</b> Poor adherence to treatment for <i>Mycobacterium avium</i> complex pulmonary disease (MAC-PD) is related to side effects (Adjemian J. et al. Ann Am Thorac Soc 2014; 11:9-16). An alternative to daily regimen is the less frequent administration but it requires the use of high drug dosage compared to a daily regimen. <b>Aim:</b> We investigated switch effects from daily to less frequent administration with a daily regimen dosage in treating MAC-PD. <b>Methods:</b> All MAC-PD patients treated with clarithromycin, ethambutol, and rifampicin or rifabutin between October 1, 2013 and September 30, 2018 in Kita-Harima Medical Center were included. <b>Results:</b> For retrospective analysis, patients were divided into two groups: A, with daily drug administration (control); and B, with switched cases from daily to less frequent administration (4, 3, or 2 times a week) with a daily regimen dosage. Group A contained 59 patients with the following features: average age 70.9 ± 12.3 years, 25 men, 39/20 patients with nodular bronchiectatic disease (NB)/fibrocavitary disease (FC), 3 patients with disease exacerbation, 37 patients with side effects, treatment period of 437.1 ± 412.4 days. Group B consisted of 10 patients with the following features: average age 69.9 ± 6.1 years, 3 men, 6/4 patients with NB/FC, 1 patient with disease exacerbation (p=0.474 vs. Group A), 2 patients with side effects (odds ratio 0.149, 95% confidence interval 0.029-0.764; p=0.022), treatment period of 574.1 ± 585.3 days (p=0.365). Trigger of switch was side effects or stable disease. <b>Conclusion:</b> Switch to intermittent treatment with a daily regimen dosage decreased side effects and hence may improve adherence.