Doxycycline shows efficacy in improving symptoms of thyroid-associated orbitopathy

Short-term outcomes of doxycycline vs placebo for mild thyroid-associated orbitopathy (TAO) were assessed in a prospective, randomized, double-masked, parallel-group trial conducted in China.

Study design

One hundred patients with mild TAO were treated with either doxycycline 50 mg once daily or placebo for 12 weeks. Primary outcomes included improvement in the composite indicator of eyelid aperture, proptosis, ocular motility, and Graves ophthalmopathy–specific quality-of-life score.

Outcomes

Thirty-eight percent of patients in the doxycycline group showed improvements in the composite indicator at week 12, compared with 16% of patients in the placebo group. There was one doxycycline-related adverse event (mild gastric acid regurgitation).

Limitations

The study is well designed; however, a larger study would be more valuable. In addition, there is evidence that TAO in Asian patients can behave differently than TAO in other populations. As this study was conducted in an all-Asian population, it is unclear if these findings are translatable to patients of other races/ethnicities.

Clinical significance

The potential use of doxycycline, an inexpensive medication with few side effects, for the treatment of mild TAO is exciting. In addition to considering selenium supplementation for mild TAO, clinicians can also consider doxycycline. As the follow-up time in this study was relatively short, additional data will be needed to see if the efficacy of doxycycline can be sustained over the long term.