JAK Inhibitors for Alopecia
What are oral JAK inhibitors?
JAK inhibitors, or Janus kinase inhibitors, represent a class of medication that targets specific pathways in the immune system. These drugs are particularly effective in treating autoimmune conditions, where the body’s immune system mistakenly attacks its own cells. In the context of alopecia areata, an autoimmune condition that causes hair loss, JAK inhibitors can help to stop the immune attack on hair follicles, potentially leading to hair regrowth. Other JAK inhibitors are also used to treat atopic dermatitis.
Baricitinib (Olumiant) and Ritlecitinib (Litfulo) are two types of JAK inhibitors used to treat severe cases of alopecia areata. While they are chemically distinct, both operate on similar principles:
Baricitinib works by inhibiting JAK1 and JAK2 enzymes, reducing the activity of the immune system and the inflammatory processes that lead to hair follicle damage.
Ritlecitinib targets a slightly different set, focusing on JAK3 and TEK tyrosine kinase (TYK2), offering a targeted approach to temper the immune response specifically involved in hair loss.
What are possible side effects of oral JAK inhibitors?
Oral JAK inhibitors carry multiple side effects due to their immunomodulatory action. They can increase the risk of infections, requiring temporary discontinuation of the medication for the immune system to combat any active infection. They may also lead to elevations in cholesterol levels and can impact liver and kidney function. Periodic blood work is essential to monitor these parameters, as well as blood cell counts. These medications also come with an elevated risk of blood clots, cardiovascular events, and certain types of cancer that may be kept at bay by a normally functioning immune system. More common side effects include nausea and acne.
How are oral JAK inhibitors used?
Oral JAK inhibitors are generally administered once daily in pill form. Given the range of potential side effects, a thorough medical evaluation is essential before starting this medication. This often includes a detailed discussion about the risks and benefits, as well as frequent monitoring through blood tests.