Cochrane review – in their own words

Folic acid or folinic acid for reducing side effects of methotrexate for people with rheumatoid arthritis Beverley Shea University of Ottawa, CIET, Institute of Population Health, Ottawa, Ontario, Canada

We have conducted a review of the effect of folic acid or folinic acid for people taking methotrexate for rheumatoid arthritis, in which we included six studies with more than 600 people (1). Folic acid and folinic acid are forms of vitamin B9, and important for health because the human body needs folate to perform many functions, including cell division, growth, and the production of new red blood cells. Folinic acid is chemically different to folic acid but both work in a similar way. If a person does not have enough folic acid or folinic acid, this is called a folate deficiency, and it may cause side effects such as mouth sores, stomach problems such as nausea or abdominal pain, liver problems or problems with producing blood cells. The relevance of this for patients with rheumatoid arthritis is that one of the commonly prescribed drugs for this condition, methotrexate (MTX), works by blocking some of the effects of folic acid. This can cause the side effects of folate deficiency, which are sometimes so bad that the person might stop taking their MTX. In doing this Cochrane Review, we wanted to examine the effect of low doses (a starting dose equal to or less than 7 mg/week) of folic acid and folinic acid in reducing gastrointestinal, hepatic (liver toxicity) and haematologic side effects of low dose MTX in patients with rheumatoid arthritis. We also wanted to determine if folate supplementation with folic acid or folinic acid reduces the arthritis benefit of MTX therapy. We have found that taking either folic or folinic acid will probably improve some side effects of MTX, such as nausea and abdominal pain and that taking either folic or folinic acid probably reduces the chance of developing abnormal liver blood tests. We learned that taking either folic or folinic acid probably helps people continue on their MTX treatment. We also learned that taking either folic or folinic acid may improve some side effects of MTX, such as mouth sores. However, we are unable to ascertain whether or not taking folic or folinic acid with MTX prevents neutropenia (prob-

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lems with producing white blood cells). Finally, taking folic or folinic acid with MTX probably has no effect on how well MTX is able to treat rheumatoid arthritis. Turning some of the above findings into numbers, for stomach problems such as nausea, vomiting or abdominal pain: we found that 9 fewer people out of 100 experienced stomach problems such as nausea up to 6 to 12 months after starting folic acid or folinic acid with their MTX (9.0% absolute improvement); 35 people out of 100 experienced stomach problems such as nausea when they took MTX alone for their rheumatoid arthritis; and 26 people out of 100 experienced stomach problems such as nausea when they took folic acid or folinic acid with their MTX. Considering liver problems identified by abnormal liver blood tests, we found that 16 fewer people out of 100 had liver problems up to 6 to 12 months after starting folic acid or folinic acid with their MTX (16.0% absolute improvement); 21 people out of 100 experienced abnormal liver blood tests when they took MTX alone for their rheumatoid arthritis; and 5 people out of 100 experienced abnormal liver blood tests when they took folic acid or folinic acid with their MTX. With regard to their ability to continue on MTX treatment, we found that 15 fewer people out of 100 who took folic acid or folinic acid dropped out of the studies for any reason (15.2% absolute improvement); 25 people out of 100 who took a placebo (fake folic acid or folinic acid) with their MTX dropped out of the studies for any reason; and 10 people out of 100 who took folic acid or folinic acid with their MTX dropped out of the studies for any reason. Finally, regarding mouth sores or ulcers, 6 fewer people out of 100 who took folic acid or folinic acid with their MTX developed mouth sores (6.2% absolute improvement); and 22 people out of 100 who took a placebo (fake folic acid) with their MTX developed mouth sores or ulcers; 16 people out of 100 who took folic acid or folinic acid with their MTX developed mouth sores or ulcers. The quality of the evidence was rated as ‘moderate’ for each outcome as assessed by GRADE, with the exception of haematologic side effects where we rated the evidence as ‘low’. There was no significant heterogeneity between trials, including where folic acid and folinic acid studies were pooled. In conclusion, this updated review with its focus on lower doses of folic acid and folinic acid and updated assessment of risk of bias aimed to give a more precise and more clinically

C 2013 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University JEBM 6 (2013) 202–203 

relevant estimate of the benefit of folate supplementation for patients with rheumatoid arthritis receiving MTX. The results support a protective effect of supplementation with either folic or folinic acid for patients with rheumatoid arthritis during treatment with MTX.

1. Shea B, Swinden MV, Tanjong Ghogomu E, Ortiz Z, Katchamart W, Rader T, et al. Folic acid and folinic acid for reducing side effects in patients receiving methotrexate for rheumatoid arthritis. Cochrane Database of Systematic Reviews 2013, Issue 5. Art. No.: CD000951.

C 2013 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University JEBM 6 (2013) 202–203 

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Folic acid or folinic acid for reducing side effects of methotrexate for people with rheumatoid arthritis.

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