Related Experiment Video
Updated: Jan 21, 2026

Drug Treatment and In Vivo Imaging of Osteoblast-Osteoclast Interactions in a Medaka Fish Osteoporosis Model
Published on: January 1, 2017
Drug-drug interactions with cannabidiol (CBD) appear to have no effect on treatment response in an open-label
Tyler E Gaston1, E Martina Bebin2, Gary R Cutter3
1Department of Neurology, Division of Epilepsy, University of Alabama at Birmingham, Birmingham, AL, USA; Division of Neurology, Birmingham Veterans Affairs Medical Center, Birmingham, AL, USA.
Objective:
We have previously shown that cannabidiol (CBD; Epidiolex®) significantly affects levels of clobazam/N-desmethylclobazam, rufinamide, topiramate, zonisamide, and eslicarbazepine. In the present study, we tested whether the presence of concomitant clobazam affected seizure frequency and severity (treatment response) 12 weeks after initiation of therapy with CBD in patients with treatment-resistant epilepsy (TRE). The secondary questions were whether the presence of any of the other antiepileptic drugs (AEDs) had an effect on seizure frequency or severity at 12, 24, or 48 weeks after therapy initiation.
Methods:
One hundred and thirty-two adults and children with TRE receiving CBD were studied prospectively. Participants were separated into two groups - either taking (CBD + clobazam) or not taking concomitant clobazam (CBD - clobazam). In the secondary analyses, participants were divided into groups depending on whether they were taking at least 1/4 of the other AEDs shown to interact with CBD (iAED). Seizure counts and Chalfont Seizure Severity Scale (CSSS) were obtained at baseline, 12, 24, and 48 weeks. Groups were compared at each respective time point in the study using generalized estimating equations (GEE) analyses.
Results:
All groups demonstrated statistically significant reductions in seizure frequency and severity from baseline (all P < 0.05). When participants on CBD + clobazam were compared with CBD - clobazam, there were no significant differences in seizure frequency and severity reduction between the groups at 12 weeks (both P > 0.05). When comparing groups with iAEDs vs. group without iAEDs, independent of coadministration of clobazam, no differences in treatment response were observed (all P > 0.05). Longitudinal analyses up to 48 weeks after therapy initiation did not reveal any differences in treatment response between groups.
Conclusion:
These analyses suggest that concomitant to CBD, AEDs may not have an effect on reducing seizure frequency and severity in patients with TRE.
Related Concept Videos
Pharmacokinetics: Drug–Drug Interactions
Pharmacokinetics: Drug–Food and Drug–Viral Interactions
Drug-Receptor Interactions
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue....
Factors Affecting Protein-Drug Binding: Drug Interactions
Displacement interactions can have varying outcomes, ranging from toxicity to virtually...
Factors Affecting Renal Clearance: Drug Distribution and Drug Interactions
One important factor is the relationship between renal clearance and the apparent volume of distribution. Renal clearance tends to be inversely proportional to the apparent volume of distribution. Drugs with an extensive distribution volume or those...
Drug-Receptor Interaction: Antagonist
Antagonists can be classified as competitive or noncompetitive based on their...

