Application of the Wagner-Nelson absorption method to the two-compartment open model

Wagner, John G.

doi:10.1007/bf01070942

Cited by 59 publications

(18 citation statements)

References 8 publications

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“…The plasma concentration data (fig. I) fitted to a one compartment open model and, in the case of oral phenacetin, to Bateman's function (7,8). Although two blood samples for phenacetin determination were drawn between the fifth and tenth minute after i. v. phenacetin injection, a distribution phase (ex-phase) of phenacetin was barely recognized.…”

Section: Resultsmentioning

confidence: 99%

Comparison of the pharmacokinetics of phenacetin in beagles after oral or intravenous administration

Souchay

Wörner

Kampffmeyer

et al. 1976

European Journal of Drug Metabolism and Pharmacokinetics

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Six beagles received intravenous and oral doses of 50 mg/kg phenacetin. Plasma concentrations of phenacetin, paracetamol, andp-phenetidin were determined and pharmacokinetic parameters calculated.Phenacetin showed rate constants for absorption and elimination of 0.025 and 0.033 (min ") and an apparent metabolic clearance rate of about 350 ml/rnin, Paracetamol and p-phenetidin elimination rate constants were 0.02 and 0.015 (min -1), respectively.There was no difference in pharmacokinetics or metabolic pattern between both routes of phenacetin administration.

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Section: Resultsmentioning

confidence: 99%

Comparison of the pharmacokinetics of phenacetin in beagles after oral or intravenous administration

Souchay

Wörner

Kampffmeyer

et al. 1976

European Journal of Drug Metabolism and Pharmacokinetics

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“…The first distribution phase occurs very quickly after i.v. administration and lasts a few minutes and is never observed after oral administration; this phenomenon of vanishing exponential terms is common after extravascular administration and was first described by Wagner et al [17]. This also explains the magnitude of the plasma concentrations and AUC values measured in Vc, because muscular mass is reduced in the elderly (mean weight 68 kg vs 47 kg).…”

Section: Discussionmentioning

confidence: 59%

Pharmacokinetics and absolute bioavailability of colchicine after i. v. and oral administration in healthy human volunteers and elderly subjects

Rochdi

Sabouraud

Girre

et al. 1994

Eur J Clin Pharmacol

106

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The pharmacokinetics of colchicine were studied in six healthy male and four elderly female volunteers after i.v. and oral administration. Plasma samples were collected over 72 h and assayed for colchicine by a specific and sensitive radioimmunoassay. Plasma concentration-time curves were fitted using a three-compartmental model after i.v. administration of 0.5 mg (healthy volunteers) and 1 mg (elderly group) colchicine. The first distribution half-life (t1/2 lambda 1) was short: 9.2 min in healthy volunteers and 3.0 min in the elderly group; the second distribution half-life (t1/2 lambda 2) was of the same order for both groups, 1.2 h. Plasma elimination half-lives were also in the same range: 30 h for healthy volunteers versus 34 h for the elderly subjects. Mean residence time was also in the same range in the two groups: 27 h in healthy volunteers and 21 h for elderly subjects. The volume of distribution (Vz) was 6.7 l.kg-1 for the healthy group and 6.3 l.kg-1 for the elderly group, while Vss was smaller: 4.2 l.kg-1 for healthy volunteers and 2.9 l.kg-1 for elderly subjects. Total body clearance was 10.5 l.h-1 for healthy and 5.5 l.h-1 for elderly subjects. After oral administration of 1 mg, lag-time was 14 min in healthy volunteers and 11 min in elderly subjects. Maximal plasma concentration was 5.5 ng.ml-1 at 62 min in the healthy group, while in the elderly group Cmax was 12 ng.ml-1 at 87 min. Mean absolute bioavailability of the tablet was the same in both groups, 44% for healthy volunteers and 45% for elderly subjects.

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“…However, in fact, their use is justified only when the pharmacokinetics strictly follow the one-compartment model, [44][45][46][47] and, unfortunately, oral paracetamol often requires the two-compartment model to characterize its kinetics. 20,21 The Loo-Riegelman method permits a more precise assessment of the rate of absorption based on the two-compartment model.…”

Section: Parameters Influenced Only By Kamentioning

confidence: 99%

Guide for judicious use of the paracetamol absorption technique in a study of gastric emptying rate of liquids

Sanaka

Kawakami

Yamanaka

1998

Journal of Gastroenterology

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The paracetamol absorption technique, a widely used method for evaluating the gastric emptying rate of liquids, appears to be performed inappropriately, resulting from a lack of consideration of pharmacokinetics in paracetamol absorption. This review suggests that appropriate study designs and logical choice of the parameters for the rate of paracetamol absorption are the cornerstone of reliable investigation of gastric emptying using the paracetamol method.

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Application of the Wagner-Nelson absorption method to the two-compartment open model

Cited by 59 publications

References 8 publications

Comparison of the pharmacokinetics of phenacetin in beagles after oral or intravenous administration

Comparison of the pharmacokinetics of phenacetin in beagles after oral or intravenous administration

Pharmacokinetics and absolute bioavailability of colchicine after i. v. and oral administration in healthy human volunteers and elderly subjects

Guide for judicious use of the paracetamol absorption technique in a study of gastric emptying rate of liquids

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