Azathioprine Mesalamine

Angiotensin converting enzyme inhibitors, azathioprine, mer-captopurine, mesalamine, sulfasalazine, sulfonamide antimicrobials, and tetracyclines... 

Proctitis Mesalamine suppository 1 g rectally daily If no response to mesalamine Prednisone 40-60 mg/day orally May reduce suppository frequency to 1 g 3 times/week taper prednisone as soon as possible Consider adding azathioprine or 6-MP 1.5-2.5 mg/kg per day orally... 

Oral corticosteroids may be used for patients who are unresponsive to sulfasalazine or mesalamine. Prednisone doses of 40 to 60 mg per day (or equivalent) are recommended.1 Azathioprine or 6-MP is used for patients unresponsive to corticosteroids or those who become steroid-dependent. Over a 12-month period, these agents have been shown to reduce the relapse rate to 36% versus 59% seen with placebo.1 Infliximab 5 mg/kg may also be used for patients who are unresponsive to conventional oral therapies and may reduce the need for colectomy after 3 months of treatment.35... 

Azathioprine, mycophenolate mofetil, and enteric-coated MPA are not metabolized through the CYP isozyme system therefore, they do not experience the same DDI profiles as cyclosporine, tacrolimus, and sirolimus. Azathioprine s major DDIs involve allopurinol, angiotensin-converting enzyme (ACE) inhibitors, aminosalicylates (e.g., mesalamine and sulfasalazine), and warfarin.11 The interaction with allopurinol is seen frequently and has clinical significance. Allopurinol inhibits xanthine oxidase, the enzyme responsible for metabolizing azathioprine. Combination of azathioprine and allopurinol has resulted in severe toxicities, particularly myelosuppression. It is recommended that concomitant therapy with azathioprine and allopurinol be avoided, but if combination therapy is necessary, the azathioprine doses must be reduced to one-third or one-fourth of the current dose. Use of azathioprine with the ACE inhibitors or aminosalicylates also can result in enhanced myelosuppression.11 Some case reports exist demonstrating that warfarin s therapeutic effects may be decreased by azathioprine.43-45... 

In the majority of patients, active Crohn s disease is treated with sulfasalazine, mesalamine derivatives, or steroids, although azathioprine, mercap-topurine, methotrexate, infliximab, and metronidazole are frequently used. 

Lowry PW, Franklin CL, Weaver AL, Szumlanski CL, Mays DC, Loftus EV, Tremaine WJ, Lipsky JJ, Weinshilboum RM, Sandborn WJ. Leucopenia resulting from a drug interaction between azathioprine or 6-mercaptopurine and mesalamine, sulphasalazine, or bal-salazide. Gut 2001 49(5) 656-64. 

Azathioprine and mercaptopurine are effective for long-term treatment of Crohn s disease and ulcerative colitis." These agents are generally reserved for patients who are refractory to steroids, and they may be associated with serious adverse effects such as lymphomas, pancreatitis, or nephrotoxicity. They are usually used in conjunction with mesalamine derivatives and/or steroids, and must be used for long periods of time (from a few weeks up to 6 months) before benefits may be observed." Remission can be prolonged by azathioprine in steroid-dependent patients with ulcerative colitis." Cyclosporine... 

The goal of treatment for active Crohn s disease is to achieve remission however, in many patients, reduction of symptoms so the patient may carry out normal activities, or reduction of the steroid dose required for control, is a significant accomplishment. In the majority of patients, active Crohn s disease is treated with sulfasalazine, mesalamine derivatives, or steroids, although azathioprine, mercap-topurine, methotrexate, or metronidazole are frequently used. 

Drug intolerance often limits the usefulness of agents used to treat IBD. Many patients receiving sulfasalazine, mesalamine, corticosteroids, metronidazole, azathioprine, mercaptopurine, or infliximab experience some undesired effects. In some cases, these adverse effects can be significant and require discontinuation of the therapy. Knowledge of the common or important adverse reactions will assist in avoiding or minimizing their effects. 

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