Elimination of ascorbic acid after high-dose infusion in prostate cancer patients: a pharmacokinetic evaluation
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Elimination of ascorbic acid after high-dose infusion in prostate cancer patients : a pharmacokinetic evaluation. / Nielsen, Torben Kjær; Højgaard, Martin; Andersen, Jon Thor Trærup; Poulsen, Henrik Enghusen; Lykkesfeldt, Jens; Mikines, Kari Joensen.
In: Basic & Clinical Pharmacology & Toxicology, Vol. 116, No. 4, 2015, p. 343-348.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Elimination of ascorbic acid after high-dose infusion in prostate cancer patients
T2 - a pharmacokinetic evaluation
AU - Nielsen, Torben Kjær
AU - Højgaard, Martin
AU - Andersen, Jon Thor Trærup
AU - Poulsen, Henrik Enghusen
AU - Lykkesfeldt, Jens
AU - Mikines, Kari Joensen
N1 - This article is protected by copyright. All rights reserved.
PY - 2015
Y1 - 2015
N2 - Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metastatic prostate cancer were treated for four weeks with fixed AA doses of 5, 30 and 60 g. AA was measured consecutively in plasma and indicated first-order elimination kinetics throughout the dosing range with supra-physiological concentrations. The target dose of 60g AA IV produced a peak plasma AA concentration of 20.3 mM. Elimination half-life was 1.87 hr (mean, SD ± 0.40), volume of distribution 0.19 L/kg (SD ±0.05) and clearance rate 6.02 L/hr (100mL/min). No differences in pharmacokinetic parameters were observed between weeks/doses. A relatively fast first-order elimination with half-life of about 2 hr makes it impossible to maintain AA concentrations in the potential cytotoxic range after infusion stop in prostate cancer patients with normal kidney function. We propose a regimen with a bolus loading followed by a maintenance infusion based on the calculated clearance.
AB - Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metastatic prostate cancer were treated for four weeks with fixed AA doses of 5, 30 and 60 g. AA was measured consecutively in plasma and indicated first-order elimination kinetics throughout the dosing range with supra-physiological concentrations. The target dose of 60g AA IV produced a peak plasma AA concentration of 20.3 mM. Elimination half-life was 1.87 hr (mean, SD ± 0.40), volume of distribution 0.19 L/kg (SD ±0.05) and clearance rate 6.02 L/hr (100mL/min). No differences in pharmacokinetic parameters were observed between weeks/doses. A relatively fast first-order elimination with half-life of about 2 hr makes it impossible to maintain AA concentrations in the potential cytotoxic range after infusion stop in prostate cancer patients with normal kidney function. We propose a regimen with a bolus loading followed by a maintenance infusion based on the calculated clearance.
U2 - 10.1111/bcpt.12323
DO - 10.1111/bcpt.12323
M3 - Journal article
C2 - 25220574
VL - 116
SP - 343
EP - 348
JO - Basic and Clinical Pharmacology and Toxicology
JF - Basic and Clinical Pharmacology and Toxicology
SN - 1742-7835
IS - 4
ER -
ID: 124426855