Early Phase 1 N=92 Randomized Basic Science

CYP3A4 Activity and Mineral Homeostasis

Vitamin D and Calcium Homeostasis

Bottom Line

View on ClinicalTrials.gov: NCT02019875 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Apr 2023

Primary outcome: Primary: 1, 25(OH) D3 Vitamin D — 3.2; 1.7; 3.7; -3.3 pM — p=0.884

Study Design & Population

Study type: Interventional
Phase: Early Phase 1
Interventions: Rifampin (Drug); Clarithromycin (Drug); Grapefruit Juice (Other); Placebo (Other)
Age: Adult · 18+ yrs
Sex: All
Sponsor: University of Washington
Primary completion: Dec 2020

Outcome Measures

Outcome	Result	p-value
PRIMARY 1, 25(OH) D3 Vitamin D	3.2; 1.7; 3.7; -3.3; -4.7; 0.4	0.884
PRIMARY 25(OH) D3 Vitamin D	-3.1; -4.3; -1.3; -1.6; 0.6; -5.0	0.62
PRIMARY Parathyroid Hormone	0.3; 0.4; 1.6; 1.0; 2.7; 0.6	0.98
PRIMARY Osteocalcin	0.0; -1.1; 0.7; 0.0; 3.7; 4.0	0.17
PRIMARY Calcium, Ionized	0.0; -0.008; -0.017; -0.011; -0.005; -0.009	0.43
PRIMARY Calcium/Creatinine (mg/g)	3.4; -9.2; -41.1; -3.8; 6.3; 41.4	0.53
PRIMARY Phosphate/Creatinine (mg/g)	8.3; 11.1; 23.3; 79.6; 5.5; 60.0	0.96

Summary

The purpose of this study is to determine whether changes in the activity of the enzyme CYP3A4 can change the Vitamin D and bone mineral homeostasis.

Eligibility Criteria

Inclusion Criteria

Subjects with no history of significant medical conditions including cardiac, pulmonary, gastrointestinal, or renal disease, HIV, diabetes mellitus or Hepatitis B or C
Subjects will be males or females 18-60 years of age
Subjects must read and understand English
Subjects must be able to provide informed consent
Subjects must be willing to avoid prescription medications, OTC drugs, dietary supplements and foods that are known to modulate CYP3A4 expression or activity
Subjects must be willing to maintain a consistent consumption of calcium and Vitamin D during the study and maintain a daily logbook of their dietary consumption
Women not currently pregnant or lactating. In addition, women participants of childbearing age must be willing to utilize a barrier method of birth control (sterilization will be acceptable)
Subjects will have no known allergies to the study drugs to be used
Subject's corrected QTc interval obtained by electrocardiogram will be ≤ 430 ms in men or ≤ 450 ms in women

Exclusion Criteria

Subjects with any significant chronic medical condition, including cardiac, pulmonary, gastrointestinal, or renal disease, HIV, diabetes mellitus or Hepatitis B or C
Subjects less than 18 or greater than 60 years of age
Subjects unable to read and understand English
Subjects unable to provide informed consent
Subjects unable to avoid prescription medications, OTC drugs, dietary supplements and foods that are known to modulate CYP3A4 expression or activity
Subjects not willing to maintain a consistent consumption of calcium and Vitamin D during the study and maintain a daily logbook of their dietary consumption
Women who are pregnant or lactating and women participants of childbearing age not willing to utilize a barrier method of birth control (sterilization will be acceptable)
Subjects with allergies to rifampin, clarithromycin or grapefruit juice
Potential participants will be excluded if they are concurrently participating in another research study
Subjects with corrected QTc interval > 430 ms in men or > 450 ms in women on electrocardiogram

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT02019875). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.