Grapefruit juice-felodipine interaction: Effect of segments and an extract from unprocessed fruit
Clin Pharmacol Ther Feb 2000 Abstract PI-71.
Commercial grapefruit juice (GFJ)
inhibits first-pass felodipine (F) metabolism to increase its oral availability.
Different parts of an unprocessed grapefruit were tested for an interaction with
F. Twelve healthy volunteers received F 10 mg ER tablet with water (W), GFJ or
blended segments (SEG) or extract from peel and core (EXT) from one whole
grapefruit, all administered as a 250 ml volume. F pharmacokinetics (mean±SEM)
are shown:
|
|
W |
GFJ |
SEG |
EXT |
|
F AUC |
25±5 |
54±8*** |
50±10* |
63±12** |
|
F Cmax |
6±1 |
16±2*** |
13±3* |
21±4** |
|
|
||||
SEG and EXT are capable of causing an interaction like that observed with GFJ. Food products made from grapefruit peel (ie, marmalades) may create this effect. The mechanism-based inhibitor, bergamottin, was found in GFJ (dose: 2.2mg), SEG (2.4mg) and EXT (0.5mg) and may be involved in the interaction.
D.
G. Bailey, PhD
G.
K. Dresser, MD
J.
H. Kreeft, MD
C.
Munoz, MD
D.
J. Freeman, PhD
J.
R. Bend, PhD
Departments of Medicine, Pharmacology & Toxicology, University of Western Ontario, London, Ontario.