How to use biologic agents in patients with rheumatoid arthritis who have comorbid disease

Although biologic disease modifying anti-rheumatic drugs (bDMARDs) have improved the quality of life of patients with rheumatoid arthritis, side effects remain a problem, especially for patients with pre-existing comorbidities. Randomized controlled trials of such drugs in rheumatoid arthritis typically exclude patients with comorbidities and are of short duration, so they do not provide data on adverse events in these people. Other data sources such as national bDMARD registries are limited by the preselection of patients for both conventional synthetic chemical compound disease modifying anti-rheumatic drugs (csDMARDs) and bDMARDs, and although these databases document comorbidity, they rarely report its severity. This too limits definitive statements on the progression or resolution of pre-existing disease. Although bDMARDs may not be contraindicated in patients with rheumatoid arthritis and certain comorbid diseases, additional assessments or precautions are recommended. This review summarizes current data on the use of bDMARDs in people with rheumatoid arthritis and common comorbid diseases. It provides an evidence base for doctors and their patients when discussing and selecting the appropriate bDMARDs.