Tetracycline, Doxycyline and Minocycline are members of the tetracycline family of antibiotics. These drugs are commonly used to fight infection but are also frequently used for their anti-inflammatory effects and are therefore used in a variety of scarring alopecias including lichen planopilaris, frontal fibrosing alopecia, and pseudopelade.
These medications have several well known mechanisms for halting inflammation: they inhibit matrix metalloproteinases, they inhibit angiogenesis, they have antioxidant effects and they block the production of various pro-inflammatory cytokines.
In terms of treatments for lymphoctic scarring alopecias, all these drugs are fairly similar in terms of efficacy but good studies have yet to be published. Personally I prefer doxycycline over others.
Doxycycline is the most commonly prescribed tetracycline family member. It can be taken with food and tends to have the least overall chances of side effects compared to minocycline and tetracycline. That is not to say of course it does not have side effects because it certainly does. Doxycycline can cause upset stomach, headaches and tends to be the most photosensitizing. Headaches and raised intracranial pressure are a rare side effect but nevertheless must be respected. Immediate cessation of the drug and medical attention is needed in anyone with persistent headaches on doxycycline. Women using doxycycline are at increased risk for vaginal yeast infections. The dose is 100 mg once to twice daily. The medication should be taken while seated upright and with plenty of water to avoid heartburn and esophagitis. Doxycycline is safer than tetracycline (see below) for use in those with kidney disease.
Recently, the possible use of low dose sub-antimicrobial doses of doxycycline have emerged on the market. This is sometimes referred to as "SD" or sub-antimicrobial dosing." Such medications are frequently used for inflammatory conditions such as rosacea. I frequently use these drugs in patients with scarring alopecia who I want to transition off higher doses doxycycline. Doxycycline formulation Oracea was approved by the FDA in 2006. Side effects are less than 100 mg conventional doxycycline but may not be appropriate as a first line off label treatment for active scarring alopecias.
Tetracycline is less expensive than doxycycline which is great but it needs to be taken on an empty stomach. This makes it less convenient. The dose is typically 500 mg twice daily for typical dosing in lichen planopilaris but this can sometimes be increased to three times daily. It must not be used in those with kidney disease and used only with extreme caution in those with liver disease. It must never be used during pregnancy and never in children (particularly under 8 years due to effects on teeth and bones). Tetracycline is less photosensitizing than doxycycline but caution is still needed. Tetracycline is more photosensitizing than minocycline.
Minocycline can sometimes be associated side effects that are not seen commonly with other tetracycline members including a serious lupus like phenomenon and other side effects like malaise and joint pains. Minocycline is a much more frequent cause of serious reactions like hypersensitivity reactions, serum sickness like reactions and single organ dysfunction. Pigmentation issues are also possible. It is less photosensitizing compared to doxycycline and tetracycline. The dose is 100 mg daily and doses up to twice daily may also be considered. Similar to tetracycline and doxycycline, minocycline must never be used in pregnancy.
All in all, one should speak with his or her dermatologist about other specific side effects of the tetracycline group. These medications may be taken for many months to even several years in those with scarring alopecia. Patients should not use retnoid medications while using tetracyclines. Moreover one should not consume iron, magnesium, calcium or aluminum at the same time as their tetracycline as these bind to the tetracycline and block absorption. Tetracyclines (all 3 members) must never be used during pregnancy and never by children under 8 due to teeth discoloration.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Vancouver office at 604.283.9299