Overall, using methotrexate for children who have severe cases of conditions such as rheumatoid arthritis appears to be mostly safe. There are several possible side effects that can range in seriousness from causing great discomfort to rare life-threatening conditions such as lymphoma. If a child’s condition is severe enough to interfere with daily activities, many doctors will prescribe this medication. The severity and frequency of side effects often depend on the dosage.
Some of the most common side effects reported when using methotrexate for children include nausea, fatigue and dizziness. There might also be mood changes, fatigue and a headache. Most of these symptoms appear within a day after the drug has been administered. More serious side effects include the development of anorexia, alopecia and hematologic toxicity. Many of these symptoms tend to be no more than mildly distressing, but some can be unpleasant enough to cause the doctor to discontinue use of the drug.
In rare cases, the use of methotrexate for children has been risky. For example, it has been connected to the development of lymphoma. When this condition has developed as the result of taking this drug, it has appeared to regress if use of the medication was discontinued. There also have been reports of the development of hypersensitivity pneumonitis, which is an inflammation of the lungs, and accelerated nodulosis, which is a skin condition.
There has been some experimentation with the dosing of methotrexate for children. This is primarily to determine whether administration at certain times or in particular conditions can reduce the incidence and severity of side effects. Some proposed measures include prepping the body before dosage in anticipation of those effects, administering the medication at bedtime and experimenting with the dosage amount and time of other drugs often taken with methotrexate. Some doctors prescribe a folic acid supplement because a folate deficiency can increase the risk of side effects.
Methotrexate is most commonly used to treat severe rheumatoid arthritis in children. It also is prescribed to treat severe psoriasis and several kinds of cancer, including breast cancer, lung cancer and leukemia. The drug works primarily by slowing the growth of different kinds of malignant cells, such as those that cause cancer and skin disorders. It also slows the activities that cause the body to attack itself, resulting in pain and swelling in the joints and bones.