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

Abstract

5-Aminosalicylic acid (5-ASA) is available in many countries in tablet, enema and suppository form. A new enteral suspension was studied in six patients with Crohn's disease affecting the upper gastrointestinal tract and in six healthy volunteers. Four grams of 5-ASA dissolved in 240 ml suspension was given 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 and n-acetyl-5-ASA analyses. All patients and subjects tolerated the procedure without problems and no side effects were encountered. All subjects and volunteers had normal renal function before and after the study; serum creatinine and blood urea nitrogen did not change. Urine recovery of 5-ASA ranged from 0.6 to 3.4 g (controls) and 0.46 to 3.6 g (patients). Stool recovery of 5-ASA was 0.1 to 0.3 g (controls) and 0.12 to 0.54 g (patients). There was delayed absorption of 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-acetyl metabolite occurred in both groups, with less than 12% stool excretion. Continued treatment induced remission. An enteral suspension of 5-ASA may be of benefit in selected patients with proximal small bowel Crohn's disease.

Gut Toxicity of 5-ASA?

“…ASA which will Jeliver high con· centrations of the drug co this area. A suspension of 5-ASA, in which all d the aJministered Jrug is in contact with the gastroduodenal mucosa, may be beneficial in the treatment d prox imal Crohn's disease(5). Prior to commencing a clinical trial of 5-ASA suspension in the treatment o/ gastroduoJ enal C rohn's, the author wished to investigate the effects of 5.…”