Pharmacokinetics and acetylation of sulfa-2-monomethoxine in humans

✍ Scribed by Tom B. Vree; Eleonora W. J. Beneken Kolmer; Yechiel A. Hekster; Minoru Shimoda; Makoto Ono; Tadayoshi Miura

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 604 KB
• Volume: 13
• Category: Article
• ISSN: 0142-2782
• DOI: 10.1002/bdd.2510130105

✦ Synopsis

In humans sulfa-2-monomethoxine (S) is metabolized by N,-acetylation (39.9 f 8.0 per cent). After an oral dose, S is eliminated biphasically (t%, 5.2 f 1.6 h and 13.2 f 3.4h) which is similar in both fast and slow acetylators. The metabolite N,-acetylsulfa-2monomethoxine (N, ) is eliminated monophasically (t%, 30.0 f 5.7 h). The intrinsic mean residence time (MRT) of N4 is 33.5 f 8.8 h. The mean total body clearance of S is 11.6 f 2.7 ml min-', and the Vd,, is 12.3 f 1.0 1. The renal clearance of S during the first day was twice as high as on the following days for two of the six volunteers (8 vs 4mlmin-I). The renal clearance of N4 during the first day, for four out of the six volunteers, was twice as high as on the following days (8 vs 4mlmin-I). The protein binding of S is 95 per cent and that of its conjugate N4 98 per cent. Approximately 80 per cent of the oral dose of S is excreted in the urine as parent drug (41.0 f 6.2 per cent) and as N, acetyl conjugate (39.9 f 8.0 per cent).