3-Week MGD treatment equivalent to 6-week course in efficacy and adverse events

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Investigators from Thailand, led by first author Phit Upaphong, MD, reported that moderate to severe meibomian gland dysfunction (MGD) was treated successfully with a 3-week course of weekly oral azithromycin that was equivalent to a 6-week course of oral doxycycline.¹

Importantly, the patients treated with azithromycin did not have a higher incidence of gastrointestinal adverse events. He is from the Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.

The 6-week treatment with doxycycline has frequently been associated with frequent gastrointestinal side effects that lead to decreased treatment compliance, which underscores the importance of the shorter treatment course.

The investigators conducted a double-masked, randomized clinical trial from September 2018 to May 2022. The study patients with moderate to severe MGD had been refractory to conservative management. The patients were randomized 1:1 to either oral azithromycin (1 gram once weekly for 3 weeks) or oral doxycycline (200 mg daily for 6 weeks), the authors recounted.

The main outcomes were the total MGD score and Ocular Surface Disease Index (OSDI) score at the initial visit and 6 and 8 weeks and the adverse events at 6 and 8 weeks. The prespecified equivalence margins for the MGD score and OSDI score were set ±2 and ±9, respectively.

MGD and OSDI results

The study include 137 eyes of 137 patients; 68 eyes were treated with azithromycin and 69 eyes with doxycycline group, About two-thirds of patients were women (mean age, 62.0 years).

The investigators reported, “The adjusted mean difference in the total MGD scores between groups at weeks 6 and 8 were −0.33 (95% confidence interval [CI], −1.70-1.03; P for equivalence , 0.01) and 0.13 (95% CI, −1.59-1.84; P or equivalence , 0 .02), respectively. The adjusted mean difference in the OSDI score between groups score at weeks 6 and 8 were −1.20 (95% CI, −5.31-2.91; P for equivalence, < 0.001) and −1.59 (95% CI, −5.73-2.55; P for equivalence, <0 .001), respectively.”

Importantly, the patients treated with azithromycin had fewer gastrointestinal adverse events (4.4% vs 15.9%; risk difference, 11.5%; 95% CI, 1.6%-21.4%; P = 0.03).

The investigators concluded, “These data support an equivalency of effects of azithromycin compared with doxycycline for MGD score and OSDI score at both follow-up times. The study did not show more gastrointestinal adverse effects in the azithromycin group. The reduced dosing and potentially fewer gastrointestinal adverse effects associated with azithromycin support its use as an alternative to doxycycline for at least 6 week.”

However, they did advise that longer follow-up is needed in each group to determine the persistence of these outcomes for this chronic condition.

Reference:

1. Upaphong P, Tangmonkongvoragul C, Phinyo P, et al. Pulsed oral azithromycin vs 6-week oral doxycycline for moderate to severe meibomian gland dysfunction: a randomized clinical trial. JAMA Ophthalmol. Published online March 23, 2023;doi:10.1001/jamaophthalmol.2023.0302