[Azathioprine toxicity in Crohn's disease: incidence, approach and course]

Azathioprine (AZA) is frequently used in Crohn's disease (CD) therapy. This paper aimed to evaluate the frequency, evolution and management of AZA side effects in CD patients.

One hundred and six CD patients under AZA therapy were evaluated prospectively from January 2002 to December 2006. Clinical and demographic data were recorded, together with a monthly laboratory control of hematological or other adverse reactions by means of clinical evaluation. Comparison was carried out between groups with and without side effects.

At least one adverse reaction was found in 56 (52.7%) of the patients studied and required a transient drug reduction; 18 (17%) had to definitely stop use of AZA, often because of hypersensitivity reactions. Nausea, vomit, although slight, occurred in 29 (27.4%). The black race and those with co-morbidities had more gastric intolerance than Caucasians and those without other associated disease (p=0.04). Leucopoenia was the more frequent side effect observed, occurring in 36 (34%). The period of AZA use was longer for patients with leucopoenia than for those without (p=0.001), while the mean dose of AZA was lower for those with leucopoenia when compared to non-leucopoenics (p=0.005). No serious infections, malignancy or death was noticed as a consequence of AZA use.

In this study use of AZA in therapy for Crohn's disease disclosed that the drug is satisfactorily safe as long as periodical clinical and laboratory supervision is carried out during treatment.