Ok, so I recently posed the question why do we need folic acid 5mg each day at the same time methotrexate is used?

Folic acid 5mg is taken on a daily basis with methotrexate (except the day methotrexate is taken) because the patient ends up with a lower level of serum folate as a side effect of methotrexate. Thus, folic acid is used to counter this effect. Simple.

I hear you ask why don’t you use folic acid on the day methotrexate is used? Again, the answer is simple. There is potential for folic acid to impact upon the efficacy of methotrexate and therefore the combination is not recommended at the same time during the week.