Does Humira cause muscle spasms?

Muscle spasms or cramps, muscle aches, and muscle weakness are rare side effects of Humira (adalimumab).

In a clinical study, only 6 percent of patients reported generalized back pain, and less than 5 percent of patients reported experiencing muscle cramps.

Humira-induced muscle cramping or pain is caused by a disturbance of the balance of specific proteins within the body, called cytokines. Humira works by blocking a cytokine called tumor necrosis factor alpha or TNF-α. An elevation of the number of TNF-α within the body causes swelling and inflammation, which can lead to the signs and symptoms of such autoimmune conditions as rheumatoid arthritis, psoriatic arthritis, or Crohn’s Disease. By binding to and suppressing TNF-α, Humira reduces inflammation within the body. In some cases, TNF-α inhibitors have been found to cause an elevation of antinuclear antibodies (ANA), which can lead to drug-induced lupus or lupus-like syndrome, of which signs and symptoms can sometimes include muscle pain.