![Page 1: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/1.jpg)
Grapefruit juice and the Grapefruit juice and the intestinal barrier in man: intestinal barrier in man:
not pulp fictionnot pulp fiction
Paul B. WatkinsPaul B. Watkins
University of North CarolinaUniversity of North Carolina
Chapel Hill, N.C.Chapel Hill, N.C.
December 2, 2003December 2, 2003
![Page 2: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/2.jpg)
time
[drug]
Effect of Grapefruit juice on plasma levels of a some drugs
![Page 3: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/3.jpg)
![Page 4: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/4.jpg)
Some drugs influenced by Some drugs influenced by grapefruit juicegrapefruit juice
Drug Drug AUC increase AUC increase
felodipinefelodipine ~ 3 fold~ 3 fold
cisapridecisapride ~ 1.4 fold~ 1.4 fold
cyclosporinecyclosporine ~ 1.5 fold~ 1.5 fold
saquinavirsaquinavir ~ 2 fold~ 2 foldterfenadineterfenadine ~ 2.5 fold ~ 2.5 fold buspironebuspirone ~ 9 fold ~ 9 fold
lovastatin/simvastatinlovastatin/simvastatin ~ 10 fold~ 10 fold
![Page 5: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/5.jpg)
Med Watch Report (January 11, 1999)Med Watch Report (January 11, 1999)
60 y/o man with diabetes mellitus, coronary heart disease,60 y/o man with diabetes mellitus, coronary heart disease, and chronic renal insufficiencyand chronic renal insufficiency 55 years treatment with lovastatin (40 mg bid), gemfibrozil years treatment with lovastatin (40 mg bid), gemfibrozil (600 mg bid) and others(600 mg bid) and others Started drinking grapefruit juice daily (8 ounces) for two weeksStarted drinking grapefruit juice daily (8 ounces) for two weeks Presented with rhabdomyolysis (CPK:44,860)Presented with rhabdomyolysis (CPK:44,860)
![Page 6: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/6.jpg)
First Pass MetabolismMetabolism by CYP3A4
![Page 7: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/7.jpg)
Kolars et al. (1994) Pharmacogenetics 4:247-59Kolars et al. (1994) Pharmacogenetics 4:247-59
LOCATION OF INTESTINAL LOCATION OF INTESTINAL CYP3A4CYP3A4
LOCATION OF INTESTINAL LOCATION OF INTESTINAL CYP3A4CYP3A4
![Page 8: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/8.jpg)
Screening HLPC fractions (Fraction C) for ability Screening HLPC fractions (Fraction C) for ability to inhibit CYP3A4 in human intestinal microsomesto inhibit CYP3A4 in human intestinal microsomes
![Page 9: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/9.jpg)
Furocoumarins in Grapefruit JuiceFurocoumarins in Grapefruit Juice
O O O
O
Bergamottin
O O O
OOH
OH
6,7-dihydroxybergamottin(DHB)
O
O
O
O
OH
O O O
OOH
O
FC708 FC726
O
O
O
O
OH
O O O
O
O
![Page 10: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/10.jpg)
Caco-2 CellsCaco-2 Cells Derived from a human colon adenocarcinomaDerived from a human colon adenocarcinoma
Upon differentiation resemble small intestinal enterocytesUpon differentiation resemble small intestinal enterocytes
In the presence of 1In the presence of 1,25-(OH),25-(OH)22-D-D3 3 express CYP3A4 express CYP3A4 Schmiedlin-Ren et al. Mol PharmacolSchmiedlin-Ren et al. Mol Pharmacol 51: 741-754, 1997 51: 741-754, 1997
culture dish
insert Basolateral medium
apical medium
Caco-2 cell monolayer
![Page 11: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/11.jpg)
gut lumen
FEL
into the body
enterocyte
FEL
FEL
FEL
FELFEL
FEL
![Page 12: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/12.jpg)
Gut lumen
FEL
FELFEL*
CYP3A4
FEL
Into the body
FEL
enterocyte
FEL
FEL
![Page 13: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/13.jpg)
Gut lumen
CYP3A4
Into the body
FEL
FEL
enterocyte FC
FC
FC*FEL
FC*X
![Page 14: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/14.jpg)
Gut lumen
FEL
Into the body
FEL
enterocyte FC
FC
FC*FEL
FC*
![Page 15: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/15.jpg)
Effect of a single glass of grapefruit juice onEffect of a single glass of grapefruit juice onconcentration of CYP3A4 in human concentration of CYP3A4 in human
small intestinal biopsiessmall intestinal biopsies
P-glycoproteinP-glycoprotein
villinvillin
CYP3A4CYP3A4
Baseline 4 hoursBaseline 4 hours
![Page 16: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/16.jpg)
FC’s in grapefruit juice reduce FC’s in grapefruit juice reduce enterocyte CYP3A4 activity in 3 waysenterocyte CYP3A4 activity in 3 ways
1). Reversible inhibition1). Reversible inhibition
2). Irreversible inactivation2). Irreversible inactivation
3). Actual loss of enzyme3). Actual loss of enzyme
![Page 17: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/17.jpg)
0
40
80
120
0 4 8 12Time (hours)
% C
on
tro
l d
jfh
jfh
d
Vehicle
DHB Treated
Time course of the effect of DHB on CYP3A4Time course of the effect of DHB on CYP3A4
0 hr0.5 hr1 hr2 hr3 hr4 hr
8 hr12 hr0.5 hr1 hr2 hr
3 hr4 hr8 hr
12 hr
CYP3A4
3A4 Standards
Vehicle DHB
![Page 18: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/18.jpg)
• Is this decrease in CYP3A4 protein content Is this decrease in CYP3A4 protein content due to decreased rate of synthesis or due to decreased rate of synthesis or accelerated rate of degradation?accelerated rate of degradation?
![Page 19: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/19.jpg)
Pulse ChasePulse Chase
Protein Synthesis 2 hours (methionine Free)
35S-Methionine
35S
35S
PulsePulse
35S
35S
Degradation 0-48 hoursMedium with 6X cold Methionine
ChaseChase
Culture Medium
![Page 20: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/20.jpg)
Effect of DHB on the Synthesis of CYP3A4 Effect of DHB on the Synthesis of CYP3A4 (Pulse (Pulse 3535S labeled Methionine)S labeled Methionine)
0 hr V
CYP3A4
0 hr D
0.5 V
0.5 D
1 hr V
1 hr D
2 hr V
2 hr D
Vehicle Rsyn = 2.0 pmol/hr/insert
Vehicle Rsyn = 2.0 pmol/hr/insert
DHBRsyn = 1.9 pmol/hr/insert
DHBRsyn = 1.9 pmol/hr/insert
0
50
100
150
0 1 2Time (h)
% c
on
tro
l
jfkd
jsfl
kd
jsd
Vehicle
DHB
Series3
Series4
![Page 21: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/21.jpg)
Effect of DHB on the Degradation of CYP3A4 Effect of DHB on the Degradation of CYP3A4 (Pulse Chase (Pulse Chase 3535S labeled Met/Cys)S labeled Met/Cys)
CYP3A4
0 0.5 1 2 4 8 12 24 48 0.5 1 2 4 8 12
Vehicle DHB
Vehicle kdeg = 0.048h-1
t1/2 = 14.4h
Vehicle kdeg = 0.048h-1
t1/2 = 14.4h
DHBkdeg = 0.21h-1
t1/2 = 3.1h
DHBkdeg = 0.21h-1
t1/2 = 3.1h
1
10
100
0 8 16 24 32 40 48Time (hours)
% 3
A4
Rem
ain
ing
Vehicle
DHB Treated
![Page 22: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/22.jpg)
SummarySummary
• DHB accelerates the rate of CYP3A4 DHB accelerates the rate of CYP3A4 degradation while having no effect on the degradation while having no effect on the rate of its synthesisrate of its synthesis
• This results in a fall in CYP3A4 half life This results in a fall in CYP3A4 half life from 14h to 3 h.from 14h to 3 h.
![Page 23: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/23.jpg)
Modeling single administration GFJ Modeling single administration GFJ effect for dose and time courseeffect for dose and time course
Takanaga, et al, Br. J. Clin Pharmacol. 49,49, 2000.Takanaga, et al, Br. J. Clin Pharmacol. 49,49, 2000.
![Page 24: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/24.jpg)
Ubiquitin- Proteasome Pathway
P450Inactivation
Peptides
Proteasome
Ubiquitination
Ub
UbDDEP
DDEP
Lactocystin
X
![Page 25: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/25.jpg)
SummarySummary
CYP3A4 Inactivation
Peptides
Proteasome
Ubiquitinating Enzymes
Ubiquitination
Ub
Ub
PhysiologicDDEP inactivatedDHB inactivated
![Page 26: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/26.jpg)
Where is this research headed?Where is this research headed?
1). 1). Development of new tools for human Development of new tools for human researchresearch
2). Improvements in oral drug delivery2). Improvements in oral drug delivery
3). New grapefruit juice 3). New grapefruit juice
![Page 27: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/27.jpg)
![Page 28: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/28.jpg)
SaquinavirSaquinavir
1). 1). Most widely used HIV protease Most widely used HIV protease inhibitorinhibitor
2). Oral availability 4-14%2). Oral availability 4-14%
3). Very rapid metabolism by CYP3A4 3). Very rapid metabolism by CYP3A4
![Page 29: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/29.jpg)
Effect of SOJ on AUC of SaquinavirEffect of SOJ on AUC of Saquinavir
Unpublished dataUnpublished data
Effect of Seville orange juice on saquinavir AUC following a single dose of 600 mg (mesylate
formulation)
0
50
100
150
200
250
300
350
400
450
Water SOJ
AUC
(ng.h
/mL)
![Page 30: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/30.jpg)
Where is this research headed?Where is this research headed?
1). 1). Development of new tools for human Development of new tools for human researchresearch
2). Improvements oral drug delivery2). Improvements oral drug delivery
3). New grapefruit juice3). New grapefruit juice
![Page 31: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/31.jpg)
Range of variation in enterocyte Range of variation in enterocyte CYP3A4 content in adultsCYP3A4 content in adults
1010
0
![Page 32: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/32.jpg)
1010
0
Variation in enterocyte CYP3A4 activityVariation in enterocyte CYP3A4 activityand the oral disposition of some substratesand the oral disposition of some substrates
![Page 33: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/33.jpg)
ConclusionConclusion
Grapefruit juice / drug interactions are of Grapefruit juice / drug interactions are of minimal importance because dramatic minimal importance because dramatic increases in oral availability only occur in increases in oral availability only occur in those patients who have very low oral those patients who have very low oral availability at baseline.availability at baseline.
![Page 34: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/34.jpg)
Effect of GFJ on CisaprideEffect of GFJ on Cisapride
Gross et al, CPT 65:395, 1999Gross et al, CPT 65:395, 1999
![Page 35: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/35.jpg)
Reasons why grapefruit juice/drug interactions shouldn’t be very important:
1). Susceptible drugs must have excellent safety profile despite large interpatient variation in exposure.
2). People with very low intestinal CYP3A4 activity will be encountered in clinical trials.
![Page 36: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/36.jpg)
Situations where grapefruit juice/drug interactions may rarely become
clinically significant:
1). Patient is requiring higher than usual dose of “susceptible” drug and begins drinking juice for the first time.
2). Patient has severe liver disease.
3). Patient has a peculiar susceptibility to an adverse effect.
![Page 37: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/37.jpg)
Where is this research headed?Where is this research headed?
1). 1). Development of new tools for human Development of new tools for human researchresearch
2). Improvements oral drug delivery2). Improvements oral drug delivery
3). New grapefruit juice 3). New grapefruit juice
![Page 38: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/38.jpg)
![Page 39: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/39.jpg)
![Page 40: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/40.jpg)
Elimination of Furanocoumarins from GFJ
Juice
FC
Serum
Absorbed DebitteredSerum
Retentate
Flavonoids
Pectin+
Cellulose
Furanocoumarins+
Flavonoids
6,7-DHB
Ultrafilration
Debitter
EthylAcetate
Etute+
EtOH +FlashChromatography
Conc.+
EtOH + FlashChromatography
Clinical Test Juice
Flavonoids
Commercial FCFFlavor Package
![Page 41: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/41.jpg)
AVERAGE PROFILE (n = 13 subjects)AVERAGE PROFILE (n = 13 subjects)
Time (hours)
Felo
dip
ine (
nM
)
0
10
20
30
40
0 6 12 18 24
OJ
0
10
20
30
40
0 6 12 18 24
OJ
GFJ
0
10
20
30
40
0 6 12 18 24
OJ
GFJ
FC-free GFJ
![Page 42: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/42.jpg)
FELODIPINE PK (n = 13 subjects)FELODIPINE PK (n = 13 subjects)
MeasureMeasure(Ave. (Ave. ± ± SD)SD)
OJOJ GFJGFJFC-free FC-free
GFJGFJ
AUC (nM-h)AUC (nM-h) 75 75 ± 36± 36 149 149 ± 68± 68** 67 67 ± 33± 33
CCmaxmax (nM) (nM) 9.0 9.0 ± 3.1± 3.1 26 26 ± 11± 11** 8.9 8.9 ± 4.0± 4.0
TTmaxmax (h) (h) 2.8 2.8 ± 0.8± 0.8 2.7 2.7 ± 0.6± 0.6 2.7 2.7 ± 0.9± 0.9
Cl/F (L/h)Cl/F (L/h) 420 420 ± 160± 160 210 210 ± 100± 100** 500 500 ± 260± 260
z z (h(h-1-1)) 0.09 0.09 ±± 0.03 0.03 0.10 0.10 ± 0.03± 0.03 0.10 0.10 ± 0.03± 0.03*Significantly different from OJ and FC-free GFJ (p < 0.001, multiple pairwise comparisons with Bonferroni corrected level of significance).
![Page 43: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/43.jpg)
ConclusionConclusion
1). It is possible to remove major FCs from 1). It is possible to remove major FCs from grapefruit juice.grapefruit juice.
2). This may not remove all GFJ / drug 2). This may not remove all GFJ / drug interactions.interactions.
![Page 44: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/44.jpg)
gut lumen
into the body
enterocyte
Pgp
CYP3A4
OATP
CsA Fexo
![Page 45: Grapefruit juice and the intestinal barrier in man: not pulp fiction Paul B. Watkins University of North Carolina Chapel Hill, N.C. December 2, 2003](https://reader038.vdocuments.net/reader038/viewer/2022110213/56649e955503460f94b99893/html5/thumbnails/45.jpg)
ThanksThanksMary Paine, Ph.D.Mary Paine, Ph.D. Shefali Malhotra Shefali MalhotraAnne Criss Anne Criss Susan Pusek Susan PusekStephane MoulyStephane Mouly
National Institutes of HealthNational Institutes of Health General Medical Sciences R37-38149General Medical Sciences R37-38149General Clinical Research Centers (NCRR).General Clinical Research Centers (NCRR).
Florida Dept of CitrusFlorida Dept of CitrusBill Widmer, Ph.D. and Bill Stinson, Ph.D.Bill Widmer, Ph.D. and Bill Stinson, Ph.D.