Monitoring blood tests in patients receiving tofacitinib (Xeljanz)

What lab tests are most important to monitor in alopecia areata patients receiving tofacitinib?

Tofacitinib is an oral medication that is used off label for the treatment of alopecia areata.  Research continues into exactly how much it helps patients with alopecia areata.  Frequent blood tests are required during the first few weeks and months of use.

Changes in four main areas are possible.

1.     Changes in blood counts. Tofacitinib can cause a reduction in neutrophils as well as lymphocytes. Patients with more severe reductions in lymphocytes appeaer to be at greatest risk for developing injections. This effect is greatest in patients receiving 10 mg compared to 5 mg.

2.     Increases in cholesterol levels. Patients experience inceases in both LDL and HDL. This effect is greatest in patients receiving 10 mg compared to 5 mg.

3.     Increase in liver enzymes. This is rather uncommon but needs to be monitored.

4.     Increase is creatine phosphokinease (CPK, CK). This occurs in a proportion of patients and is usually withouth consequence for most patients. The drug must be stopped however, when levels increase 50 % above baseline. This effect on CPK levels is greatest in patients receiving 10 mg compared to 5 mg.

Comment: 

Frequent blood tests are needed when starting tofacitinib. Slight changes are not uncommon but more significant changes may require dose reduction or even stopping of the drug. Anyone starting tofacitinib requires close monitoring.