P549. Azathioprine in the elderly - Is it tolerated and is it safe?
S. Dharmasiri, H. Johnson, S. McLaughlin, S. Weaver, Royal Bournemouth Hospital, Depatment of Gastroenterology, Bournemouth, United Kingdom
The use of Azathioprine (AZA) for maintenance of remission in Inflammatory Bowel Disease (IBD) is common practice as part of national and international guidelines. Side effects however are common. Of 353 consecutive patients commencing AZA in our organisation, 36% were not taking it at one year. With an ageing population, IBD is increasingly relevant in those over 75 years old. However there is little data concerning the efficacy and tolerability of AZA in this age group.
We maintain a prospective database of IBD patients. All patients commenced on AZA between June 2005 and October 2012 over the age of 75 were identified. Thiopurine Methyl Transferase (TPMT) levels were checked in all patients and AZA was prescribed at 2–2.5 mg/kg, with 50% dose reduction in those with low TPMT. We monitor full blood count and LFTs weekly for 8 weeks after commencing therapy.
25 patients were identified, (7 CD, 18 UC). The mean age at which AZA was started was 78 (range 75–86), 16 were male (64%). All patients were followed up for at least one year. 12 (48%) were intolerant of AZA. Reasons for stopping AZA were; hepatitis, 2 (8%); vomiting, 5 (10%); pancreatitis, 1 (4%); myelosupression (1); joint pain (1); infection (1); and general malaise (1). The mean duration of AZA use in these patients was 34 days (Range 3–89). 13 (52%) tolerated the drug well with one of this group having the drug actively withdrawn at 701 days in complete clinical, endoscopic and histological remission. There were four deaths (16%). Two died in the group intolerant of AZA (84 year old died of stroke 888 days after 13 days of AZA; 82 year old died in the community 140 days after 5 days of AZA). Two people died in the AZA treated group (83 year old died in the community on day 1476 of AZA; 79 year old died following cardiac arrest on day 212 of AZA).
Our data demonstrate that AZA is an effective treatment in the elderly. It appears to be less well tolerated than in the general population with 48% intolerant of the drug within 3 months. Within the limitations of this study it appears to be safe. The increased incidence of drug intolerance in this population group may suggest that low-dose azathioprine and allopurinol co-therapy should be considered first-line therapy in this group. A further study to clarify this is required.