Mercaptopurine pancreatitis with

MERCAPTOPURINE ANTIGOUT DRUGS -ALLOPURINOL t mercaptopurine levels with risk of toxicity (e.g. myelosuppression, pancreatitis) Azathioprine is metabolized to mercaptopurine. Allopurinol inhibits hepatic metabolism of mercaptopurine 1 doses of azathioprine and mercaptopurine by up to three-quarters and monitor FBC, LFTs and amylase carefully... 

Agents targeting the excessive immune response or cytokines involved in IBD are potential treatment options (Table 16-3). Azathioprine and its active metabolite 6-mercaptopurine (6-MP) are inhibitors of purine biosynthesis and reduce IBD-associated GI inflammation. They are most useful for maintaining remission of IBD or reducing the need for long-term use of corticosteroids. Use in active disease is limited by their slow onset of action, which may be as long as 3 to 12 months. Adverse effects associated with azathioprine and 6-MP include hypersensitivity reactions resulting in pancreatitis, fever, rash, hepatitis, and leukopenia.25,26... 

Immunosuppressive agents such as azathioprine and mercaptopurine (a metabohte of azathioprine) are sometimes used for the treatment of IBD. These agents are generally reserved for cases that are refractory to steroids and may be associated with serious adverse effects such as lymphomas, pancreatitis, or nephrotoxicity. Cyclosporine has been of short-term benefit in acute, severe ulcerative colitis when used in a continuous infusion. 

Immunosuppressants such as azathioprine and mercaptopurine have a significant potential for adverse reactions, including bone marrow suppression, and have been associated with lymphomas (in renal transplant patients) and pancreatitis. Myelosuppression resulting in leukopenia is related to a deficiency in TPMT in some patients. 

Dose-related toxicities of azathioprine or 6-mercaptopurine include nausea, vomiting, bone marrow depression (leading to leukopenia, macrocytosis, anemia, or thrombocytopenia), and hepatic toxicity. Routine laboratory monitoring with complete blood count and liver function tests is required. Leukopenia or elevations in liver chemistries usually respond to medication dose reduction. Severe leukopenia may predispose to opportunistic infections leukopenia may respond to therapy with granulocyte stimulating factor. Hypersensitivity reactions to azathioprine or 6-mercaptopurine occur in 5% of patients. These include fever, rash, pancreatitis, diarrhea, and hepatitis. 

Pancreatitis due to azathioprine or mercaptopurine has usually been reported as part of the hypersensitivity syndrome (SEDA-16,520) (SEDA-20,341). It has mostly been observed in patients with inflammatory bowel disease, and required withdrawal of treatment in 1.3% of patients with Crohn s disease (3). Pancreatitis was not dose-related within the therapeutic range of doses and often recurred in patients who were rechallenged with either drug (SEDA-20, 341) (35). Fatal hemorrhagic pancreatitis occurred in one patient, but a role of concomitant drugs was also possible (SEDA-20, 341). Pancreatitis or hyperamylasemia were not significantly different in renal transplant patients randomly assigned to receive azathioprine or ciclosporin, and other causative factors were found in most patients with pancreatitis (36). 

Immunosuppressants such as azathioprine and mercaptopurine have a significant potential for adverse reactions. Azathioprine causes bone marrow suppression and has been associated with lymphomas (in renal transplant patients), skin cancer, and pancreatitis (about 3% of patients). Some investigators believe that induction of leukopenia may be necessary for therapeutic effect. Mercaptopurine causes adverse reactions similarly to azathioprine however, there are fewer reports of lymphomas with this agent. In one cohort of IBD patients, adverse effects from mercaptopurine were as follows pancreatitis, 1.2% allergic reactions, 3.9%, significant leukopenia, 11.5% and infectious complications, 14%. Ten percent of patients who received azathioprine or mercaptopurine required discontinuation of treatment because of adverse effects. Allopurinol inhibits the metabolism of mercaptopurine, and a dosage reduction of the latter is required when the two are used in combination. 

The median dose of mercaptopurine in adults fell four- to fivefold after the addition of allopurinol lOOmg/day in 20 adults and children, with preferential metabolism of 6-mercaptopurine to 6-methylmercaptopurine [174 ]. Before the addition of allopurinol, six patients had mild rises in aminotransferase activities associated with high concentrations of methylmercaptopurine all subsequently had normalization with mercaptopurine dosage reduction. There were no adverse reactions, such as rash, renal failure, or pancreatitis, attributable to the combination of allopurinol and mercaptopurine. Three patients developed mild leukopenia after starting allopurinol. 

Hypersensitivity reactions In 21 patients with inflammatory bowel disease who had hypersensitivity reactions to azathioprine or mercaptopurine within 6 weeks, thioguanine 10-40 mg/day elicited hypersensitivity reactions in only four, after a median of 9 days pancreatitis did not recur [1185]. 

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