As with all medications, taking certolizumab 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 certolizumab. When monitored properly the vast majority of side effects are rare and most improve over time and are reversible.
Firstly, certolizumab can increase your risk of infections.
In rare cases, certolizumab can cause a reaction (redness, pain and itching) at the injection site. Talk to your health-care provider if these symptoms become severe.
Also in unusual circumstances, some people may experience headaches with certolizumab. If this becomes severe please speak with your health-care provider.
Some people have developed lupus-like symptoms that disappeared after the medication was stopped. If you have chest pains that do not go away, shortness of breath or a rash on your cheeks or arms that gets worse in the sun, call your doctor right away.
There have been rare cases of disorders that affect the nervous system of people taking certolizumab or other TNF-blockers. 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.
Certolizumab very rarely can cause a drop in blood counts.