Injections may be recommended for people who are not responding to oral methotrexate or are developing intestinal side effects such as nausea. Methotrexate should not be taken more often than one 24-hour period per week. More frequent administration can be associated with serious side effects. Mark a calendar to remind yourself when to take your dose. If you become confused about when to take the drug, call your doctor to clarify the situation before you take the next dose.
Side effects do occur in some people taking methotrexate.
At the low weekly doses used to treat rheumatoid arthritis however, serious side effects are rare. The most common side effects include upset stomach, nausea, vomiting, loss of appetite, diarrhea, or mouth sores. If these develop, you should contact your doctor immediately. A change in the dose or in how you take your methotrexate may reduce these side effects Occasionally, side effects such as headaches, dizziness, mood alterations, skin rashes, or unexplained weight loss may occur. Increased sensitivity to sun has also been observed, although this is rare.