Nucleic acids are linear polymers (chains) of nucleotides. Each nucleotide consists of three components: a purine or pyrimidine nucleobase (sometimes termed nitrogenous base or simply base), a pentose sugar, and a phosphate group. The substructure consisting of a nucleobase plus sugar is termed a nucleoside.
Other studies of Remicade and methotrexate indicate that the two medications together can successfully reduce symptoms of psoriasis and psoriatic arthritis, the researchers report. Studies of Humira and Enbrel in conjunction with methotrexate also revealed the combination to be more effective than the biologic alone.
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.