The systemic load and efficient delivery of active 5-aminosalicylic acid in patients with ulcerative colitis on treatment with olsalazine or mesalazine

Autor: G Støa-Birketvedt, J Florholmen
Rok vydání: 1999
Předmět:
Zdroj: Alimentary Pharmacology & Therapeutics. 13:357-361
ISSN: 0269-2813
DOI: 10.1046/j.1365-2036.1999.00483.x
Popis: Background There have been reports of nephrotoxic reactions in patients with ulcerative colitis treated with 5-aminosalicylic acid (5-ASA) preparations. Aim To compare the efficacy in delivery of active 5-ASA to the colon and the systemic load as the basis for potential long-term toxicity during treatment with olsalazine or mesalazine in patients with ulcerative colitis in remission. Patients and methods Fifteen patients with ulcerative colitis were treated with olsalazine or mesalazine, each for 7 days in an open, randomized, crossover design study. 5-ASA and acetyl-5-ASA (Ac-5-ASA) in plasma and urine were measured by high performance liquid chromatography. Results The plasma concentration of 5-ASA was 1.2 +/- 0.1 micromol/L (mean +/- S.E.M.) for olsalazine and 8.0 +/- 1.9 micromol/L for mesalazine, while the plasma concentration of Ac-5-ASA was 2.8 +/- 0.2 micromol/L for olsalazine and 10.8 +/- 1.6 micromol/L for mesalazine. The amount of 5-ASA excreted in the urine was 68 +/- 30 micromol/24 h for olsalazine and 593 +/- 164 micromol/24 h for mesalazine. The amount of Ac-5-ASA in the urine was 1260 +/- 102 micromol/24 h for olsalazine and 3223 +/- 229 micromol/24 h for mesalazine. The urinary recovery of total 5-ASA plus Ac-5-ASA (as a percentage of the given dose) was 23 +/- 2.1% for olsalazine and 39 +/- 3.6% for mesalazine. The ratio between the plasma concentrations of mesalazine and olsalazine differed significantly both for 5-ASA (5.1) and Ac-5-ASA (3.6); for 5-ASA (9. 9) and Ac-5-ASA (2.6) in urine, and for the urinary recovery of total 5-ASA plus Ac-5-ASA (1.7). Moreover, in the mesalazine group there was a large variation in the individual plasma concentrations of 5-ASA and Ac-5-ASA, with maximal values 5-6-fold higher than that in the olsalazine group. Conclusion The systemic load of active 5-ASA is significantly higher for mesalazine than for olsalazine, when based on the dosages given and when calculated on an equimolar basis. Some of the patients in the mesalazine group showed unexpected high levels of plasma and urinary 5-ASA concentrations, a finding which may have long-term safety implications.
Databáze: OpenAIRE
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