Adalimumab: a review of side effects

Adalimumab (Humira®) is a human monoclonal TNF-α antibody that blocks the effects of TNF-α. It is administered by subcutaneous injection. It has been approved alone or in combination with methotrexate for the treatment of rheumatoid arthritis in the EU and US. Approval for its use for the treatment of psoriasis, psoriatic arthritis and ankylosing spondylitis is expected in the near future. Its side effect profile is favourable when compared with traditional systemic treatments for these diseases. It does not require laboratory monitoring. The most common side effects of adalimumab are injection site reactions. Adalimumab increases the risk of rare serious infections. There is a two-fold risk of serious infections with the use of adalimumab, as reported in the Premier trial. This risk should not be minimised in this way. It should not be used during periods of active infection. Its most notable infectious complication is the reactivation of tuberculosis. Tuberculosis screening should be according to country standards and may or may not include purified protein derivative test or chest X-ray. Deep fungal and other serious and atypical infection can also be promoted by adalimumab. It has been associated infrequently with skin rashes. Rare side effects include: worsening or initiation of congestive heart failure, a lupus-like syndrome, a promotion of lymphoma, medically significant cytopenias, and worsening or initiation of a multiple sclerosis/neurological disease. There has been reported pancytopenia and elevated transamines with the use of adalimumab, which suggest that laboratory monitoring blood counts and liver functions, at least intermittently, are useful. In patients with any of the foregoing problems, its use should be extremely carefully considered. Adalimumab is a useful medication which can be safely used if its side effects are recognised.