On the prescribing of oral doxycycline or minocycline by UK optometrists as part of management of chronic Meibomian Gland Dysfunction (MGD)

Purpose: To review the special pharmacology of tetracycline antibiotics as anti-inflammatory drugs for treatment of obstructive Meibomian gland disease (MGD). Methods: PubMed was used as principal resource for articles, regardless of language, on doxycycline and minocycline with key interests being on their serum and tissue pharmacokinetics and their use in clinical studies as part of management of MGD. Results: With oral dosing of between 50 and 200. mg, peak blood levels of these antibiotics have been reported to be predictably dose-dependent at between 1 and 5 microgram/mL, with human tear film levels not being detectable with 100. mg dosing of doxycycline but levels of 0.2 microgram/mL with 200. mg minocycline. That these two tetracycline antibiotics reach the conjunctiva is indicated by conjunctival pigmentary changes due to photosensitization after very long term use. Based the reported use in a range of clinical studies on MGD, dosing with these two antibiotics for MGD is likely to be useful at relatively low doses (e.g. 100. mg for doxycycline or 50 mg for minocycline, either at once or twice daily depending on severity at presentation and previous history) continued for 2 to 3 months, with the expected outcome being small-to-substantial decreases in abnormal appearance of the glands (from -4 to -89%) and increases in tear film stability (from 21 to 273%). Conclusions: Oral doxycycline and minocycline have predictable pharmacokinetics and have been reported to improve Meibomian gland dysfunction over a few months of use.