Pharmacokinetics and presystemic gut metabolism of methyldopa in healthy human subjects.
J Clin Pharmacol
; 35(3): 275-80, 1995 Mar.
Article
em En
| MEDLINE
| ID: mdl-7608316
ABSTRACT
This study examined the pharmacokinetics and metabolism of methyldopa after giving single 250-mg oral and intravenous doses to 16 healthy human volunteers. A 48-hour washout period was allowed between oral and intravenous treatments. Blood and urine samples were collected; methyldopa was assayed in blood and urine, and its metabolites (methyldopa sulfate, alpha-methyldopamine, and alpha-methyldopamine sulfate) were assayed in urine. Pharmacokinetic parameters were recorded as follows half-life was 2.0 +/- 0.7 hours; total body and renal clearance were 268 +/- 72 and 107 +/- 35 mL/min, respectively; and volume of distribution at steady-state was 33 +/- 11 L. The absolute bioavailability of the drug was 42 +/- 16%. The measurable metabolites in urine after oral and intravenous administration accounted for 27% and 17% of the dose, respectively. Methyldopa sulfate was the most abundant metabolite recorded; its quantity was higher after oral than after intravenous administration, 20.1 +/- 5.7% versus 6.7 +/- 5.3% of the dose (P < .05), suggesting significant presystemic gut metabolism. First-pass gut metabolism for methyldopa was estimated to be 17.6 +/- 6.9% of the dose given.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Mucosa Intestinal
/
Metildopa
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Clin Pharmacol
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Canadá