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Updated: Oct 19, 2026

An Intestine/Liver Microphysiological System for Drug Pharmacokinetic and Toxicological Assessment
Published on: December 3, 2020
Pharmacokinetic and pharmacodynamic drug interactions between digoxin and macrogol 4000, a laxative polymer, in
I Ragueneau1, J M Poirier, N Radembino
1Clinical Pharmacology Unit and Department of Pharmacology, Saint-Antoine University Hospital, 184 rue du Faubourg Saint-Antoine, 75012 Paris, France.
Aims:
The aim of this study was to examine the bioequivalence between a single oral dose of digoxin administered alone and with a coadministration of macrogol 4000 (a laxative polymer) in 18 healthy volunteers.
Methods:
This was an open, randomised, two-way cross-over study, with a single dose oral administration of 0.5 mg digoxin administered alone or in combination with macrogol 4000, 20 g day-1 during 8 days. Pharmacokinetics of digoxin, heart rate and PR ECG interval at rest were assessed.
Results:
Macrogol 4000 coadministration was associated with a 30% decrease of digoxin AUC and a 40% decrease in its Cmax (P<0.05). Digoxin tmax and t1/2,z were not significantly altered. Heart rate and PR interval did not differ during the two therapeutic sequences, digoxin alone and digoxin in combination.
Conclusions:
Macrogol 4000 coadministration interacts with single-dose digoxin pharmacokinetics. This is most likely due to a reduction of the intestinal absorption of digoxin. However, there was no consequence of this interaction on heart rate and AV conduction.
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