Doxycycline Treatment in Mild Thyroid-Associated Ophthalmopathy

The Effect of Subantimicrobial Dose Doxycycline in Mild Thyroid-Associated Ophthalmopathy

The aim of this study is to evaluate the effects of subantimicrobial dose doxycycline (50 mg/d), administered for 12 weeks, on patients with mild Thyroid-Associated Ophthalmopathy (TAO).

Thyroid-Associated Ophthalmopathy is an autoimmune disease that can be treated by corticosteroids and surgery. But they often cause severe side-effects and are usually used for treating moderate-sever and sight-threatening TAO. Wait and see will be the first choice for the patient with mild TAO.

Subantimicrobial dose (SD) doxycycline displays a strong anti-inflammatory and immunomodulatory function, which is independent of its antibiotic properties. Data from clinical trials demonstrated that SD doxycycline was effective in moderating inflammation in a variety of autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, rosacea and periodontitis.

We propose to test the effect of subantimicrobial dose doxycycline for mild TAO.

Inclusion Criteria:

• Clinical diagnosis of Thyroid-associated ophthalmopathy
• Mild TAO
• Normal serum free thyroxine and free triiodothyronine concentrations
• No previous specific therapy for TAO, except for local measures
• Written informed consent is obtained

Exclusion Criteria:

• Pregnant females as determined by positive (serum or urine) hCG test at screening or prior to dosing, or lactating females
• Uncontrolled diabetes or hypertension
• History of mental / psychiatric disorder
• Hepatic dysfunction (Alb, AST, ALT and Alkaline phosphates levels must be within normal range for eligibility)
• Renal impairment (Urea and Creatinine levels must be within normal range)
• Tetracycline allergy or intolerance