Like all medications, taking tocilizumab carries some risk of side effects, which must be balanced with the potential benefits. In general, the risk of joint damage and permanent disability (resulting from arthritis) is much greater than the risks of side effects from tocilizumab. When monitored properly the vast majority of side effects are rare, most improve over time and are reversible.
Firstly, tocilizumab can increase your risk of infections.
In rare cases, tocilizumab can cause an allergic reaction during the infusion (flushing, itching, changes in heart rate and blood pressure, etc.). A health-care provider will monitor for this reaction during the infusion.
For people taking the medication by injection, tocilizumab can rarely cause a reaction (redness, pain, and itching) at the injection site. Talk to your health-care provider if these symptoms become severe.
Again in uncommon circumstances, people may experience upper respiratory tract infections (common cold, sinus infections) headaches and an increase in blood pressure with tocilizumab. Other rare side effects include cold sores, blisters and shingles. If any of these symptoms become severe please speak with your health-care provider. Some people have also developed skin infections (sometimes with fever and chills). If you believe you have an infection please contact your health-care provider.
Very rarely tocilizumab has been associated with stomach perforations (holes in the lining of the stomach), usually as a complication of diverticulitis (infection of the large intestine). This requires immediate medical attention. If you develop fever and severe stomach pain that does not go away, seek medical attention.
There have been rare cases of disorders that affect the nervous system of people taking tocilizumab. Signs that you could be experiencing a problem affecting your nervous system include numbness or tingling, problems with your vision, weakness in your legs and dizziness. If you experience these symptoms, seek medical attention.
Tocilizumab can rarely affect your blood counts, liver function and cholesterol levels. Your health-care provider will use blood tests to monitor for these changes.