Generally, the drug has been well tolerated.
The commonest reported adverse reaction was acceleration of the time of intestinal transit (diarrhea 37% of patients). Few cases of abdominal pains have been described. The modification of the dose in the initial periods of the treatment (2 to 4 weeks) has allowed to surpass or to diminish these adverse events.
Other adverse events reported are urine discoloration in 14.4% cases and single case of hypokalemia, hepatotoxicity resulting into acute hepatitis and fatal toxic epidermal necrolysis (Lyell's syndrome).