Vree TB, Hekster YA, Tijhuis MW, Baakman M, Oosterbaan MJ, Termond EF. Effects of methoxy groups in the NI-substituent of sulfonamides on the pathways of elimination in man. The acetylation-deacetylation equilibrium and mechanisms of renal excretion of sulfisomidine, sulfamethomidine and sulfadimethoxine.
PHARMACEUTISCH WEEKBLAD. SCIENTIFIC EDITION 1984;
6:150-6. [PMID:
6483571 DOI:
10.1007/bf01954042]
[Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Sulfisomidine, sulfamethomidine, sulfadimethoxine and their corresponding N4-acetyl derivatives were administered to man. The percentages of acetylation and deacetylation and those of protein binding, the half-lives of elimination and the apparent and true renal clearance values were measured. No acetylation phenotype could be demonstrated in these compounds. Methoxy substitution in the NI-pyrimidine group of sulfisomidine affects predominantly the renal clearance value and mechanism of the parent compound but has no influence on the renal clearance of the N4-acetyl derivatives. The renal clearance value of sulfisomidine is 232 +/- 33 ml/min, of sulfamethomidine 21.60 +/- 16.4 ml/min and of sulfadimethoxine 10.87 +/- 10.44 ml/min. The renal clearance values of the corresponding N4-acetylsulfonamide derivatives are 314 +/- 91 ml/min, 342 +/- 63 ml/min and 202 +/- 65 ml/min respectively. Tubular reabsorption, caused by methoxy substitution in the NI-pyrimidine ring, lowers the rate of elimination and increases the half-life. The half-life of sulfisomidine is 8.5 +/- 0.5 h, of sulfamethomidine 27.8 +/- 5.3 h and of sufadimethoxine 34.6 +/- 10.4 h.
Collapse