A CBD-Hydroxychloroquine Combination Drug Was Safe and Well-Tolerated in Healthy Volunteers
A Phase I trial found that IHL-675A, a fixed-dose combination of CBD and hydroxychloroquine for inflammatory conditions, was generally well-tolerated with a safety profile similar to each drug given separately.
Quick Facts
What This Study Found
IHL-675A was generally well-tolerated with no serious adverse events. Both CBD and HCQ were bioavailable when co-administered. CBD exposure was approximately 50% higher (Cmax) in the combination versus Epidiolex alone, while HCQ exposure was slightly decreased (15% lower AUC). The 90% CIs for both drugs extended beyond standard bioequivalence acceptance intervals.
Key Numbers
36 participants, 12 per arm. No SAEs. CBD Cmax approximately 50% higher in combination vs Epidiolex alone. HCQ AUC approximately 15% lower in combination vs Plaquenil alone. 90% CIs outside 80-125% bioequivalence range for both drugs.
How They Did This
Phase I, randomized, open-label, comparator-controlled trial with 36 healthy volunteers assigned 1:1:1 to IHL-675A (150mg CBD + 200mg HCQ), Plaquenil alone (200mg HCQ), or Epidiolex alone (150mg CBD). Safety, pharmacokinetics, and metabolite profiles assessed over 4 weeks.
Why This Research Matters
This is the first clinical trial of a fixed-dose CBD-hydroxychloroquine combination being developed for rheumatoid arthritis and other inflammatory conditions. The safety and PK data support continued development toward efficacy trials.
The Bigger Picture
Combining CBD with established anti-inflammatory drugs is a growing area of pharmaceutical development. If CBD enhances or complements the anti-inflammatory effects of hydroxychloroquine, this combination could offer benefits for conditions like rheumatoid arthritis with potentially fewer side effects than current regimens.
What This Study Doesn't Tell Us
Phase I in healthy volunteers only (no patients with inflammatory conditions). Small sample size. Open-label design. The increased CBD and decreased HCQ exposures in the combination need to be evaluated for clinical significance. Single-dose study.
Questions This Raises
- ?Will the altered PK profile of the combination affect efficacy?
- ?Does the 50% higher CBD exposure translate to greater anti-inflammatory effect or increased side effects?
Trust & Context
- Key Stat:
- No serious adverse events in any treatment arm
- Evidence Grade:
- Phase I trial with 36 participants. Provides safety and PK data only; efficacy has not been assessed.
- Study Age:
- Published in 2025.
- Original Title:
- An open-label phase I comparator-controlled clinical trial to assess tolerability and pharmacokinetics of IHL-675 A a fixed dose combination of cannabidiol plus hydroxychloroquine in healthy volunteers.
- Published In:
- Scientific reports, 15(1), 19357 (2025)
- Authors:
- Mbogo, George Williams, Kroner, Pia, Walsh, Rosemarie, Newchurch, Jonathan, Bleackley, Mark Robert
- Database ID:
- RTHC-07091
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
What is this drug for?
IHL-675A combines CBD and hydroxychloroquine in a single capsule for treating inflammatory conditions like rheumatoid arthritis. It is still in early-stage clinical development.
Why combine CBD with hydroxychloroquine?
Both have anti-inflammatory properties through different mechanisms. The combination aims to provide enhanced anti-inflammatory effects while potentially allowing lower doses of each drug.
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Cite This Study
https://rethinkthc.com/research/RTHC-07091APA
Mbogo, George Williams; Kroner, Pia; Walsh, Rosemarie; Newchurch, Jonathan; Bleackley, Mark Robert. (2025). An open-label phase I comparator-controlled clinical trial to assess tolerability and pharmacokinetics of IHL-675 A a fixed dose combination of cannabidiol plus hydroxychloroquine in healthy volunteers.. Scientific reports, 15(1), 19357. https://doi.org/10.1038/s41598-025-04573-5
MLA
Mbogo, George Williams, et al. "An open-label phase I comparator-controlled clinical trial to assess tolerability and pharmacokinetics of IHL-675 A a fixed dose combination of cannabidiol plus hydroxychloroquine in healthy volunteers.." Scientific reports, 2025. https://doi.org/10.1038/s41598-025-04573-5
RethinkTHC
RethinkTHC Research Database. "An open-label phase I comparator-controlled clinical trial t..." RTHC-07091. Retrieved from https://rethinkthc.com/research/mbogo-2025-an-openlabel-phase-i
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.