ISSN:
1365-2036
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Background: Knowledge of the bioavailability of 5-aminosalicylic acid (5-ASA, mesalazine) from the different 5-ASA-containing drugs is important for rational therapy of inflammatory bowel diseases. Methods: The local and systemic bioavailability of 5-ASA from a controlled release 5-ASA preparation (Pentasa—2, 4 or 6 g/day) was investigated and compared with the azo-bond 5-ASA preparation olsalazine (Dipenturn—2 g/day) in 13 healthy volunteers during steady state conditions. Results: The therapeutically relevant parameter of 5-ASA at the rectal level, expressed as the mean concentration in faecal water, showed a significant trend towards higher concentrations with increasing Pentasa dose: 9.2 mmol/L, 19.0 mmol/L and 24.4 mmol/L, respectively. The concentration of olsalazine 2 g/day was 16.0 mmol/L. The concentration of the metabolite N-acetyl-5-aminosalicylic acid (Ac-5-ASA) did not rise with increasing Pentasa dose, indicating saturable presystemic acetylating capacity of 5-ASA. Total urinary excretion of 5-ASA and Ac-5-ASA, as a percentage of the daily ingested 5-ASA dose, remained constant on the three Pentasa doses, but there was a significant increase in the 5-ASA fraction. Mean steady state plasma concentrations of 5-ASA and Ac-5-ASA were significantly higher on Pentasa 4 g/day and 6 g/day than on 2 g/day. Values on Pentasa 2 g/day were comparable with those on olsalazine 2 g/day. Conclusions: The study confirmed that 5-ASA is released from Pentasa in a predictable manner, the amount released increasing with dose. Olsalazine is an excellent generator of 5-ASA in the colon.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2036.1994.tb00290.x
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