Drug Interaction Report

GENERALLY AVOID: Coadministration of baricitinib with other immunosuppressive agents may potentiate the risk of infections as well as lymphoma and other malignancies. Serious and sometimes fatal infections due to bacterial, mycobacterial, invasive fungal, viral, or other opportunistic pathogens have been reported in patients receiving baricitinib, most of whom were taking concomitant immunosuppressants such as methotrexate or corticosteroids. The most common serious infections reported with baricitinib treatment include pneumonia, herpes zoster, and urinary tract infection. Opportunistic infections include tuberculosis, multidermatomal herpes zoster, esophageal candidiasis, pneumocystosis, acute histoplasmosis, cryptococcosis, cytomegalovirus, and BK virus. Lymphoma and other malignancies, including melanoma and non-melanoma skin cancers, have also been observed with the use of baricitinib and other Janus kinase inhibitors.

MANAGEMENT: Concomitant use of baricitinib with other Janus kinase (JAK) inhibitors, biologic disease-modifying antirheumatic drugs (DMARDs), or potent immunosuppressants (e.g., azathioprine, cyclosporine) is not recommended. Patients receiving baricitinib should be closely monitored for the development of signs and symptoms of infection during and after treatment, including the possible development of tuberculosis in patients who tested negative for latent tuberculosis infection prior to initiating therapy. If a serious infection, an opportunistic infection, or sepsis develops, baricitinib should be interrupted until the infection is controlled.

ADJUST DOSING INTERVAL: Consumption of food has led to a 27% decrease in the bioavailability of orally administered tacrolimus.

MANAGEMENT: Tacrolimus should be administered at least one hour before or two hours after meals.

GENERALLY AVOID: Grapefruit juice has been reported to increase tacrolimus trough concentrations. Data are limited, but inhibition of the CYP450 enzyme system appears to be involved.

MANAGEMENT: The clinician may want to recommend that the patient avoid ingesting large amounts of grapefruit juice while taking tacrolimus.