Disposition of Mesalazine from Mesalazine-Delivering Drugs in Patients with Inflammatory Bowel Disease, with and without Diarrhoea

AbstractRijk MCM, van Schaik A, van Tongeren JHM. Disposition of mesalazine from mesalazine-delivering drugs in patients with inflammatory bowel disease, with and without diarrhoea. Scand J Gastroenterol 1992;27:863-868.The disposition of mesalazine from the azo compounds sulphasalazine and olsalazine (Dipentum®) and from the slow-release mesalazine drugs Pentasa®, Asacol®, and Salofalk® was studied in 20 patients with inflammatory bowel disease. Ten of them had diarrhoea, and 10 had normal stools. On the last 2 days of a 7-day maintenance treatment with each of the study drugs urine and faeces were collected for determination of mesalazine, acetyl-mesalazine, and unsplit azo compound. In patients with and without diarrhoea the urinary and the faecal excretion of acetyl-mesalazine was lowest during treatment with olsalazine. The proportion of acetyl-mesalazine in faeces was highest during treatment with Pentasa in both groups. The presence of diarrhoea was associated with a decrease in the proportion of acetyl-mesalazine in faeces during treatment with all drugs, not significant only for Pentasa. The proportion of unsplit azo compound in faeces increased in the case of diarrhoea to almost 50%. It is concluded that in patients with inflammatory bowel disease diarrhoea substantially influences the disposition from ail these drugs except Pentasa.Key Words: Inflammatory bowel diseasemesalazinepharmacokinetics