Drug & supplement interaction

Cannabichromene (cbc) + Phensuximide

Phensuximide brand name: Milontin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Cannabichromene (cbc) has a moderate interaction with Phensuximide. Using cannabichromene with drugs that have sedative properties may cause additive therapeutic and adverse effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cannabichromene (cbc) and Phensuximide

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CNS DEPRESSANTS

Why this applies to Phensuximide

Phensuximide falls under CNS DEPRESSANTS — the group Cannabichromene (cbc) interacts with.

Using cannabichromene with drugs that have sedative properties may cause additive therapeutic and adverse effects.
Animal research shows that cannabichromene, given as a single dose intraperitoneally, increases the sedative response to the drugs hexobarbital, barbital, and zoxazolamine. However, this effect was not maintained when cannabichromene was given continuously. After receiving cannabichromene daily for 7 days, the sedative effect of these drugs was reduced when compared with a control group or a single dose of cannabichromene.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Phensuximide (Milontin) is an older medicine used to control absence (petit mal) seizures, and like many seizure drugs it can leave you feeling drowsy, foggy, dizzy, or tired. CBC isn't a prodrug situation here, so the concern is simpler: it may add to that sedation. The theory is that pairing CBC with a calming medicine like phensuximide could stack the drowsiness, making you sleepier or less alert than usual.

I want to be honest about how thin the evidence is. This comes only from animal studies using other sedatives, not human data on phensuximide. Interestingly, the extra sedation showed up after a single dose but faded with daily use. We just don't know how it plays out in people. Please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hatoum NS, Davis WM, Waters IW, Elsohly MA, Turner CE. Synergism of cannabichromene and CNS depressants in mice. Gen Pharmacol. 1981;12(5):351-6. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Cannabichromene (cbc) Also Interacts With Other Medications

Cannabichromene (cbc) has 247 moderate known drug interactions in our database — the Phensuximide one above is one of them. If you take anything else, check it against the full list below.

Moderate 247 No known interaction 2,583 (incl. Phensuximide)
Taking anything else?

Check Another of Your Medications Against Cannabichromene (cbc)

Covers the 2,830 medications we’ve checked against Cannabichromene (cbc). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Phensuximide

This page covers Cannabichromene (cbc) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phensuximide page lists 105 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 82 moderate · 16 minor.

From our pharmacist’s overview on the Phensuximide page

“Phensuximide (Milontin) treats absence seizures and is sedating on its own, which is why this supplement list earns real caution rather than a quick skim. Most of the risk is sedation stacking, since 78 of the 105 ingredients on file have calming effects of their own, and the heaviest combinations can push drowsiness toward dangerous s…”

Reviewed by 2 · Jul 18, 2026

Open the Phensuximide interaction page

How much people look this up

Where Cannabichromene (cbc) and Phensuximide Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Cannabichromene (cbc)
Steady interest

#1,158 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phensuximide
Steady interest

#2,050 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Cannabichromene (cbc)

What is Cannabichromene (cbc)?

Cannabichromene (cbc)
  • Pain relief
  • Inflammation
  • Mood and anxiety
  • Skin and acne concerns
  • Brain and nerve health

Cannabichromene (CBC) is a non-intoxicating cannabinoid found in the cannabis plant that is being studied for possible pain, anti-inflammatory, and nervous-system effects. Almost all current evidence comes from laboratory and animal research, so we do not yet know how well it works or how safe it is in people. Talk with your pharmacist or doctor before using any CBC product, and avoid it during pregnancy and breastfeeding.

Read the full Cannabichromene (cbc) monograph & all interactions
Keep checking

Other Drugs & Cannabichromene (cbc)

Browse every other medication we’ve checked against Cannabichromene (cbc) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
247Moderate
0Minor
2,582No known interaction
247 Moderate 2,582 No interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Cannabichromene (cbc) page.

No interaction 2,582 drugs checked — show the list

We also checked Cannabichromene (cbc) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,582 medications checked with no known interaction — see the full Cannabichromene (cbc) list.

See the full Cannabichromene (cbc) interactions page
See every supplement checked against Phensuximide, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Cannabichromene (cbc) monograph › Uses, safety, and every drug interaction in one place Phensuximide supplement interactions › Every supplement checked against Phensuximide, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cannabichromene (cbc) and Phensuximide Together: Common Questions

Can you take Cannabichromene (cbc) with Phensuximide?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Cannabichromene (cbc) and Phensuximide interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Phensuximide and Cannabichromene (cbc)?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.