Plasma concentrations and pharmacokinetics of dihydralazine after single oral doses to human subjects

✍ Scribed by A. R. Waller; L. F. Chasseaud; T. Taylor; A. Darragh; D. A. O'Kelly

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 295 KB
• Volume: 1
• Category: Article
• ISSN: 0142-2782
• DOI: 10.1002/bdd.2510010203

✦ Synopsis

Abstract

After single oral doses of 20 mg of a suspension of dihydralazine sulphate to human subjects, the peak of mean plasma concentrations of dihydralazine of 47·0 ng ml^−1^ ± 11·0 standard deviation (S.D.) (n = 7) was reached at 1 h. Mean concentrations declined biphasically with apparent half‐lives of 0·57 and 4·96 h respectively.

Dihydralazine was partly converted to hydralazine. The peak of mean plasma concentrations of the latter drug of 3·9 ng ml^−1^ ± 1·7 S.D. (n = 7) occurred at 1–2 h after dosing with dihydralazine sulphate and declined to 1–5 ng ml^−1^ ± 1·5 S.D. at 6 h.

Of the seven subjects studied, three were classified as fast and four as slow acetylators. Mean clearances appeared to be slightly more rapid in fast acetylators (1·63 1 min^−1^ ± 0·32 S.D.) when compared to slow acetylators (1·31 1 min^−1^ ± 0·31 S.D.) but this difference and differences in plasma concentrations and in areas under the plasma drug concentration‐time curves were not significant (p > 0·1).