A to Z of MS Azathioprine (Imuran)

Product name

Imuran

Azathioprine is a drug that has been used as a disease modifying therapy in multiple sclerosis. Research suggests that efficacy could be similar to that of the beta interferon drugs although because of its side effect profile it is usually reserved for people with moderately aggressive disease.

A small study of people who did not respond to either treatment with beta interferon 1a or azathioprine alone found a combination therapy was well tolerated and after two years of treatment no serious side effects were reported. Mean number of relapses over the trial period was significantly lower than that before combined treatment. Further larger studies are required.

How azathioprine works

Azathioprine is an immunosuppressant drug. It is used to prevent the rejection of transplanted organs, in the treatment of some cancers and also in the treatment of conditions such rheumatoid arthritis, lupus and hepatitis. In MS, studies suggest that azathioprine reduces relapse rate and slows down disability progression.

How is azathioprine given?

It is recommended that azathioprine is taken orally as tablets.

Side effects and contraindications

Although generally well tolerated, side effects can include severe nausea, severe anaemia or leucopenia (shortage of white blood cells) and liver damage. Careful monitoring of blood count and liver function is required during treatment. There is also an increased risk of developing cancer if the drug is taken long-term, though short-term use (less than five years) is not associated with a significantly increased risk.

References

Casetta I, et al.
Azathioprine for multiple sclerosis.
Cochrane Database of Systematic Reviews 2007;(4):CD003982.
abstract

Lus G, et al.
Azathioprine and interferon beta (1a) in relapsing-remitting multiple sclerosis patients: increasing efficacy of combined treatment.
European Neurology 2004;51(1):15-20.
abstract

Patient Information Leaflet

Imuran (EMC website)

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