ISSN:
1573-8744
Keywords:
diazoxide
;
pharmacokinetics
;
stable-isotope dilution
;
GC-mass fragmentography
;
solubility
;
excretion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A specific, sensitive, and accurate assay for diazoxide in human plasma and urine samples was developed utilizing stable-isotope dilution-GC-mass fragmentography. 3-Trideuterodiazoxide (d 3-diazoxide) served as internal standard, and diazoxide was N-methylated with diazomethane prior to GC. Plasma elimination half-lives of diazoxide ranged within 20–53 hr in four severely hypertensive patients, which did not correlate with endogenous plasma creatinine levels. A rapid infusion over 10–15 sec of an antihypertensive dose presumably resulted in a very transient precipitation of diazoxide due to its limited solubility of approximately 380 Μg/ml plasma. Urinary excretion accounted for 4–6% of the dose within 24 hr after administration in the four patients studied and totalled 19% and 22% in two patients. Renal clearance of diazoxide was below 1 ml/min on the first day following administration and increased to 2–3 ml/min on consecutive days. It was concluded that renal excretion of diazoxide is self-limited by antihypertensive doses in severely hypertensive patients. The major route of elimination in these patients may be due to metabolism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01060037
