Pharmacokinetics of 5-Aminosalicylic Acid Enteral Suspension in Crohn's Disease Patients and Normal Volunteers

5-Aminosalicylic acid (5-ASA) is available in many countries intablet, enema and suppository form. A new enteral suspension was studied in sixpatients with Crohn's disease affecting the upper gastrointestinal tract and in sixhealthy volunteers. Four grams of 5-ASA dissolved in 240 ml suspension wasgiven via a nasoduodenal tube over 4 h. Blood was drawn at 0, l, 2, 3, 4, 5, 6, 7,8, 12 and 24 h, and 24 h urine and stool were collected for 5-ASA andn-acetyl-5-ASA analyses. All patients and subjects tolerated the procedurewithout problems and no side effects were encountered. All subjects and volunteershad normal renal function before and after the study; serum creatinine andblood urea nitrogen did not change. Urine recovery of 5-ASA ranged from 0.6to 3.4 g (controls) and 0.46 to 3.6 g (patients). Stool recovery of 5-ASA was 0.1to 0.3 g (controls) and 0.12 to 0.54 g (patients). There was delayed absorptionof 5-ASA in patients compared to controls, shown by time to peak concentrations(4 to 6 h versus 3 h). Predominantly urine excretion of the n-acetylmetabolite occurred in both groups, with less than 12% stool excretion. Continuedtreatment induced remission. An enteral suspension of 5-ASA may be ofbenefit in selected patients with proximal small bowel Crohn's disease