Pharmacokinetics and pharmacodynamics of dexamethasone sodium-m-sulfobenzoate (DS) after intravenous and intramuscular administration: A comparison with dexamethasone phosphate (DP)
G. Hochhaus et al., Pharmacokinetics and pharmacodynamics of dexamethasone sodium-m-sulfobenzoate (DS) after intravenous and intramuscular administration: A comparison with dexamethasone phosphate (DP), J CLIN PHAR, 41(4), 2001, pp. 425-434
The pharmacokinetics (PK) and pharmacodynamics (effects on blood lymphocyte
s) of dexamethasone (D) after intravenous (i.v.) administration of dexameth
asone phosphate (DP, 10 mg, equivalent to 8.3 mg of dexamethasone) and afte
r intravenous and intramuscular (i.m.) administration of dexamethasone sulf
obenzoate sodium (DS, 9.15 mg, equivalent to 6 mg of dexamethasone) were as
sessed. Only 25% of DS was converted into dexamethasone with a half-life fo
r DS of 5.4 hours and 7.4 hours after i.v, and i.m. administration, respect
ively. Consequently, the mean residence time of D after both i.m, and i.v.
administration of DS (10.4-11.6 h) was longer than that after DP administra
tion (6.1 h). The smaller lymphocyte suppression induced by DS (50% of that
after DP administration) was shown to be related to differences in the pha
rmacokinetics. This study revealed significant differences in the pharmacok
inetics of D after administration of DS and DP and stresses the importance
of the prodrug for the pharmacological response. Because of the slow and in
complete conversion of DS into dexamethasone, its use in emergency medicine
situations should be critically evaluated. (C) 2001 the American College o
f Clinical Pharmacology.