Trial Outcomes & Findings for Effects of Garlic Supplements on Opioids in Healthy Volunteers (NCT NCT00499460)

NCT ID: NCT00499460

Last Updated: 2017-04-07

Results Overview

Oxycodone oral clearance is computed by Dose/AUC, where AUC is the area under the plasma oxycodone concentration-time curve from time zero to infinity. Oral clearance is a measure of the rate at which oxycodone is cleared from the body via metabolism.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

15 participants

Primary outcome timeframe

Serial blood sampling over 24 hours after a 15-mg oral dose of oxycodone

Results posted on

2017-04-07

Participant Flow

Recruitment period was between November 2006 and August 2008. Healthy subjects were recruited from the University of Washington and Fred Hutchinson Cancer Research Center campuses through public notices.

Participant milestones

Participant milestones
Measure
Garlic First, Then Placebo
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Placebo First, Then Garlic
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Intervention 1 (30 Days)
STARTED
8
7
Intervention 1 (30 Days)
COMPLETED
6
7
Intervention 1 (30 Days)
NOT COMPLETED
2
0
Intervention 2 (30 Days)
STARTED
6
7
Intervention 2 (30 Days)
COMPLETED
6
6
Intervention 2 (30 Days)
NOT COMPLETED
0
1

Reasons for withdrawal

Reasons for withdrawal
Measure
Garlic First, Then Placebo
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Placebo First, Then Garlic
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Intervention 1 (30 Days)
Withdrawal by Subject
1
0
Intervention 1 (30 Days)
Fainting upon Blood Draw
1
0
Intervention 2 (30 Days)
Withdrawal by Subject
0
1

Baseline Characteristics

Effects of Garlic Supplements on Opioids in Healthy Volunteers

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Garlic First, Then Placebo
n=6 Participants
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Placebo First, Then Garlic
n=6 Participants
Two 30-day treatment periods separated by a washout of at least 4 weeks. In Period 1, participants receive oral placebo tablet twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29. In Period 2, participants receive oral garlic powder (Nature's Way Garlicin tablet) twice daily on days 1-30, and undergo testings with oxycodone on day 28 and a combination of oral midazolam and digoxin on day 29.
Total
n=12 Participants
Total of all reporting groups
Age, Continuous
28.3 years
STANDARD_DEVIATION 5.2 • n=5 Participants
30.5 years
STANDARD_DEVIATION 6.0 • n=7 Participants
29.9 years
STANDARD_DEVIATION 5.8 • n=5 Participants
Sex: Female, Male
Female
3 Participants
n=5 Participants
3 Participants
n=7 Participants
6 Participants
n=5 Participants
Sex: Female, Male
Male
3 Participants
n=5 Participants
3 Participants
n=7 Participants
6 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
n=5 Participants
0 Participants
n=7 Participants
1 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
5 Participants
n=5 Participants
6 Participants
n=7 Participants
11 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Asian
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
White
6 Participants
n=5 Participants
5 Participants
n=7 Participants
11 Participants
n=5 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Region of Enrollment
United States
6 Participants
n=5 Participants
6 Participants
n=7 Participants
12 Participants
n=5 Participants

PRIMARY outcome

Timeframe: Serial blood sampling over 24 hours after a 15-mg oral dose of oxycodone

Oxycodone oral clearance is computed by Dose/AUC, where AUC is the area under the plasma oxycodone concentration-time curve from time zero to infinity. Oral clearance is a measure of the rate at which oxycodone is cleared from the body via metabolism.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Oxycodone Oral Clearance
1.82 L/min
Standard Deviation 0.40
2.04 L/min
Standard Deviation 0.51

SECONDARY outcome

Timeframe: Repeated testing for tolerance to Cold Pressor Test just before and at 45, 90, 150 and 300 min after a single 15-mg oral dose of oxycodone

Cold Pressor Test measures response to experimentally induced pain, in this case by immersion of a subject's hand in icy-cold water. Tolerance is the duration of time a subject is able to keep his/her hand immersed in the cold water. A prolongation in tolerance time indicates analgesic response to oxycodone treatment. Cold Pressor Tolerance AUC is the area under the tolerance versus time curve over a 300-min period after a test dose of oxycodone. Because of non-normality in sample distribution, log transformed AUC estimates were analyzed by Generalized Linear Model.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Cold Pressor Tolerance AUC
3.513 log (sec*min)
Standard Deviation 0.904
3.715 log (sec*min)
Standard Deviation 0.604

SECONDARY outcome

Timeframe: SSE scores at 150 min after a single 15-mg oral dose of oxycodone

Subjects rated the bodily side effects they experienced at 90, 150 and 300 min after oxycodone administration on a 35-item Somatic Side Effects (SSE) questionnaire. Total score (i.e., average of the scores for all 35 items) ranges on a numerical scale from 0 (no somatic side effects) to a maximum of 4 (extreme somatic aide effects). Only the peak SSE scores at 150 min are reported herein.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Somatic Side Effects Total Score
0.560 units on a scale
Standard Deviation 0.140
0.711 units on a scale
Standard Deviation 0.184

SECONDARY outcome

Timeframe: CASE scores at 150 min after a single 15-mg oral dose of oxycodone

Subjects rated the mental side effects they experienced at 90, 150 and 300 min after oxycodone administration on a 36-item Cognitive-Affective Side Effects (CASE) questionnaire. Total score (i.e., average of the scores for all 36 items) ranges on a numerical scale from 0 (no somatic side effects) to a maximum of 4 (extreme somatic aide effects). Only the peak CASE scores at 150 min are reported herein.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Cognitive-Affective Side Effects Total Score
1.884 units on a scale
Standard Deviation 0.118
1.714 units on a scale
Standard Deviation 0.147

SECONDARY outcome

Timeframe: Serial blood sampling over 6 hours after a 5-mg oral test dose of midazolam

Midazolam when given orally is a probe substrate for the in vivo intestinal and hepatic activity of CYP3A (Cytochrome P450 3A) enzymes. The phenotype index in this case is the area under the plasma midazolam concentration from time zero to 360 min after a 5-mg oral test dose. A decrease in oral midazolam AUC indicates enhanced activity of CYP3A enzymes, possibly as a result of enzyme induction.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Oral Midazolam Test
2491 (ng/mL)*min
Standard Deviation 789
2495 (ng/mL)*min
Standard Deviation 825

SECONDARY outcome

Timeframe: Serial blood sampling over 4 hours after a 0.5-mg oral test dose of digoxin

Digoxin when given orally is a probe substrate for the efflux activity of P-glycoprotein in the small intestine. The phenotype index in this case is the area under the plasma digoxin concentration from time zero to 240 min after a 0.5-mg oral test dose. A decrease in oral digoxin AUC indicates an enhanced activity of P-glycoprotein, possibly as a result of transporter upregulation.

Outcome measures

Outcome measures
Measure
Garlic
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following garlic powder treatment were calculated by pooling data from the active treatment period in each assigned arm
Placebo
n=12 Participants
Mean and standard deviation of oxycodone oral clearance following placebo treatment were calculated by pooling data from the placebo treatment period in each assigned arm
Oral Digoxin Test
231 (ng/mL)*min
Standard Deviation 50
226 (ng/mL)*min
Standard Deviation 58

Adverse Events

Garlic

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Placebo

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Danny D. Shen, Member (Retired)

Clinical Research Division, Fred Hutchinson Cancer Research Center

Phone: 206-685-2920

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place