Because disease-modifying anti-rheumatic drugs (DMARDs) work throughout the body to fight rheumatic arthritis (RA), their powerful action typically does cause some side effects, commonly:
Stomach upset. DMARDs sometimes cause nausea, sometimes with vomiting, or diarrhea. Other medicines can help treat these symptoms, or they often improve as you get used to the drug. If the symptoms are too uncomfortable to tolerate, your rheumatologist will try a different medication.
Liver problems. These are less common than stomach upset. Your doctor will check blood tests on a regular basis to make sure your liver is not being harmed.
Blood problems. DMARDs can affect the immune system and raise the risk of infection. Infection-fighting white blood cells may also be decreased. Low red blood cells (anemia) can make you tired more easily. A simple blood test by your doctor every so often will make sure your blood counts are high enough. You should learn about possible side effects of any medicine you are taking and discuss them with your doctor until you feel comfortable.