Cannabidiol (cbd) + Belladonna, Ergotamine, Phenobarbital
Belladonna, Ergotamine, Phenobarbital brand name: Bellergal-S.
Belladonna, Ergotamine, Phenobarbital falls into 5 drug categories that Cannabidiol (cbd) can interact with; the most serious is rated moderate. Theoretically, cannabidiol might have additive effects if used with other CNS depressants.
Read the full interaction reportCannabidiol (cbd) and Belladonna, Ergotamine, Phenobarbital
These two interact in 5 distinct ways. Each one is explained separately below.
Why Are There 5 Interactions?
Cannabidiol (cbd) interacts with whole categories of medication. Belladonna, Ergotamine, Phenobarbital falls into 5 of those categories, so it can interact with Cannabidiol (cbd) in 5 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
CNS DEPRESSANTS
1 of 5Why this applies to Belladonna, Ergotamine, Phenobarbital
Belladonna, Ergotamine, Phenobarbital falls under CNS DEPRESSANTS — the group Cannabidiol (cbd) interacts with.
Preliminary clinical research, case reports, and animal studies suggest that high dose cannabidiol has sedative and hypnotic effects. Theoretically, concomitant use of cannabidiol with drugs with sedative and anesthetic properties may cause additive therapeutic and adverse effects.
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.
The piece of Bellergal-S that matters most here is the phenobarbital, a barbiturate that calms the brain and can make you drowsy. CBD can have its own mild sedative effect, so taking the two together could stack up. The concern is feeling extra sleepy, foggy, dizzy, or slowed down. Phenobarbital is already a strong sedative, so I'd take this seriously even though the evidence here is mostly theoretical.
This isn't a sharp chemical reaction, just two things that both slow you down adding up. There's no need to panic, but please don't drive or do anything risky until you know how the combo affects you. Talk with your pharmacist or doctor before pairing CBD with this medication so they can weigh it for your situation.
- Carlini EA, Cunha JM. Hypnotic and antiepileptic effects of cannabidiol. J Clin Pharmacol 1981;21(8-9 Suppl):417S-27S. PubMed
- Monti JM. Hypnoticlike effects of cannabidiol in the rat. Psychopharmacology (Berl) 1977;55(3):263-5. PubMed
- Pickens JT. Sedative activity of cannabis in relation to its delta'-trans-tetrahydrocannabinol and cannabidiol content. Br J Pharmacol 1981;72(4):649-56.
- Perez-Vilar S, Karami S, Long K, Leishear K. Cannabidiol exposures in the United States, National Poison Data System, July 2014-June 2021. Clin Toxicol (Phila) 2022. PubMed
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
2 of 5Belladonna, Ergotamine, Phenobarbital also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
In vitro and animal research shows that cannabidiol inhibits CYP3A4. In human studies and case reports, cannabidiol has been associated with an increase in plasma levels of the CYP3A4 substrates zonisamide, tacrolimus, everolimus, citalopram, midazolam, and methadone.
Interaction 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..
Bellergal-S is an old combination product that contains belladonna (a drying agent), ergotamine, and phenobarbital (a sedative barbiturate). Here's the piece that matters: CBD can block a liver enzyme called CYP3A4, which helps clear the ergotamine portion of this medicine. If that breakdown slows down, ergotamine can build up in your body, and ergotamine is one of those drugs where extra levels can cause real trouble, like nausea, tingling or coldness in the hands and feet, or in rare cases poor circulation.
This concern is well documented for CYP3A4 in general, though it hasn't been studied with this exact combo product. Phenobarbital adds its own sedation risk. Please don't start or stop anything on your own. Run it by your pharmacist or doctor first so they can check the doses and watch for side effects.
- Yamaori S, Ebisawa J, Okushima Y, et al. Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety. Life Sci 2011;88(15-16):730-6. PubMed
- Harvey DJ. Absorption, distribution, and biotransformation of the cannabinoids. Marijuana and Medicine. 1999;91-103. DOI
- Bornheim LM, Everhart ET, Li J, Correia MA. Characterization of cannabidiol-mediated cytochrome P450 inactivation. Biochem Pharmacol 1993;45(6):1323-31. PubMed
- Gaston TE, Bebin EM, Cutter GR, Liu Y, Szaflarski JP; UAB CBD Program. Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia. 2017 Sep;58(9):1586-92. PubMed
- Leino AD, Emoto C, Fukuda T, Privitera M, Vinks AA, Alloway RR. Evidence of a clinically significant drug-drug interaction between cannabidiol and tacrolimus. Am J Transplant. 2019;19(10):2944-2948. PubMed
- Wiemer-Kruel A, Stiller B, Bast T. Cannabidiol Interacts Significantly with Everolimus-Report of a Patient with Tuberous Sclerosis Complex. Neuropediatrics. 2019. PubMed
- Madden K, Tanco K, Bruera E. Clinically Significant Drug-Drug Interaction Between Methadone and Cannabidiol. Pediatrics. 2020;e20193256. PubMed
- Anderson LL, Doohan PT, Oldfield L, et al. Citalopram and Cannabidiol: In Vitro and In Vivo Evidence of Pharmacokinetic Interactions Relevant to the Treatment of Anxiety Disorders in Young People. J Clin Psychopharmacol. 2021. PubMed
- Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
- Treyer A, Reinhardt JK, Eigenmann DE, Oufir M, Hamburger M. Phytochemical comparison of medicinal cannabis extracts and study of their CYP-mediated interactions with coumarinic oral anticoagulants. Med Cannabis Cannabinoids. 2023;6(1):21-31. PubMed
- Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.
CYTOCHROME P450 2C19 (CYP2C19) INDUCERS
3 of 5Belladonna, Ergotamine, Phenobarbital also falls under CYTOCHROME P450 2C19 (CYP2C19) INDUCERS.
Cannabidiol is a substrate of CYP2C19 enzymes. Theoretically, drugs that induce CYP2C19 enzymes might decrease the levels and effects of cannabidiol.
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.
Here's the key thing to know: in this pairing, it's the medicine affecting your CBD, not the other way around. The phenobarbital in Bellergal-S is a known enzyme booster (it speeds up CYP2C19, one of the liver pathways that clears CBD). So if you take CBD alongside this combo, your body may break the CBD down faster, leaving lower levels in your system. In plain terms, your CBD might simply work less well than you expect.
This is a theoretical concern based on how these compounds behave, not something proven in studies, so I wouldn't be alarmed. Your belladonna, ergotamine, and phenobarbital effects shouldn't change from the CBD here. Still, since phenobarbital is a sedative and product quality varies, please run it by your pharmacist or doctor before combining them.
- Epidiolex (cannabidiol) prescribing information. Greenwich Biosciences, Inc., Carlsbad, CA, 2019. Available at: https://www.epidiolex.com/sites/default/files/EPIDIOLEX_Full_Prescribing_Information.pdf (accessed 5/9/2019)
CYTOCHROME P450 3A4 (CYP3A4) INDUCERS
4 of 5Belladonna, Ergotamine, Phenobarbital also falls under CYTOCHROME P450 3A4 (CYP3A4) INDUCERS.
Cannabidiol is a substrate of CYP3A4 enzymes. Theoretically, drugs that induce CYP3A4 enzymes might reduce the levels and effects of cannabidiol.
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.
Here's the thing to know about this combo: the phenobarbital part of Bellergal-S is a classic 'enzyme booster.' It speeds up a liver pathway called CYP3A4, which happens to be one of the main routes your body uses to break down CBD. So in this pairing, it's the medicine affecting the supplement, not the other way around. The likely result is that your CBD gets cleared out faster, leaving lower levels and a weaker effect. If you're using CBD for sleep or anxiety, you might simply notice it doesn't do much.
I want to be honest that this is theoretical, based on how these drugs behave rather than solid human studies, so don't panic. Phenobarbital is the powerful piece here, so never adjust it on your own. Just check in with your pharmacist or doctor before adding CBD.
- Epidiolex (cannabidiol) prescribing information. Greenwich Biosciences, Inc., Carlsbad, CA, 2019. Available at: https://www.epidiolex.com/sites/default/files/EPIDIOLEX_Full_Prescribing_Information.pdf (accessed 5/9/2019)
CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES
5 of 5Belladonna, Ergotamine, Phenobarbital also falls under CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES.
In vitro research shows that cannabidiol inhibits CYP2B6. However, this interaction has yet to be reported in humans. Until more is known, use with caution. Theoretically, concomitant use of cannabidiol with CYP2B6 substrates might increase the risk for adverse effects from these substrates.
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.
This combination pill (Bellergal-S) contains phenobarbital, a barbiturate sedative, and that is the piece CBD may bump into. Phenobarbital is partly broken down by a liver enzyme called CYP2B6. In lab dish studies, CBD appears to slow this enzyme down. If that happened in people, phenobarbital could clear out more slowly and build up a bit, which might mean more drowsiness, dizziness, grogginess, or slowed breathing.
Here's the honest part: this is theoretical right now, based only on test-tube research, and it hasn't actually been reported in real patients. So I wouldn't panic. Still, phenobarbital is a strong drug with a narrow safety margin, so please don't add CBD to this without checking with your pharmacist or doctor first.
- Yamaori S, Maeda C, Yamamoto I, Watanabe K. Differential inhibition of human cytochrome P450 2A6 and 2B6 by major phytocannabinoids. Forensic Toxicol 2011;29:117-24. DOI
- Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Cannabidiol (cbd) Also Interacts With Other Medications
Cannabidiol (cbd) has 1,050 moderate known drug interactions in our database — the Belladonna, Ergotamine, Phenobarbital one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Cannabidiol (cbd)
We haven’t checked that one against Cannabidiol (cbd) yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Cannabidiol (cbd). Pick one to open its full report.
See Every Supplement That Interacts With Belladonna, Ergotamine, Phenobarbital
This page covers Cannabidiol (cbd) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Belladonna, Ergotamine, Phenobarbital page lists 250 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 Grapefruit (major).
By severity: 11 major · 200 moderate · 39 minor.
From our pharmacist’s overview on the Belladonna, Ergotamine, Phenobarbital page
“Bellergal-S packs three drugs into one tablet, and its supplement list earns real respect before you mix in anything else. Phenobarbital is a sedating barbiturate, belladonna adds drying anticholinergic effects, and ergotamine constricts blood vessels, so this combination collects interactions from several directions at once.”
Reviewed by 2 · Jul 18, 2026
Open the Belladonna, Ergotamine, Phenobarbital interaction page
Where Cannabidiol (cbd) and Belladonna, Ergotamine, Phenobarbital 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.
#426 of 1,452 supplements looked up here in the last 7 days
#119 of 2,830 medications looked up here in the last 7 days
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.
About Cannabidiol (cbd)
What is Cannabidiol (cbd)?
- Anxiety and stress
- Sleep problems
- Chronic pain
- Certain seizure disorders
- Inflammation
CBD is a compound from the cannabis (hemp) plant that does not cause a 'high.' It has strong evidence only for certain rare seizure disorders (as a prescription drug), while most other popular uses are still backed by limited or early research. Product quality varies a lot, so talk with your pharmacist or doctor before using it, especially if you take other medicines.
Other Drugs & Cannabidiol (cbd)
Browse every other medication we’ve checked against Cannabidiol (cbd) — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1,050 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Theophylline ›
- Nifedipine ›
- Ibuprofen ›
- Metronidazole ›
- Diphenhydramine ›
- Hydrocortisone ›
- Naproxen ›
- Erythromycin ›
- Estradiol ›
- Propranolol ›
- Lidocaine ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Flurazepam ›
- Glyburide ›
- Triazolam ›
- Zopiclone ›
- Bupropion ›
- Ciprofloxacin ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Isotretinoin ›
- Orphenadrine ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Apomorphine ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Indomethacin ›
- Miconazole ›
- Morphine Sulfate ›
- Nitrazepam ›
- Trimipramine ›
- Acetaminophen ›
- Amphetamine ›
- Buprenorphine ›
- Conjugated Estrogens ›
- Diazepam ›
- Everolimus ›
- Griseofulvin ›
- Ivabradine ›
Showing 60 of 1,050 moderate interactions — see all 1,050 on the Cannabidiol (cbd) page.
No interaction 1,779 drugs checked — show the list
We also checked Cannabidiol (cbd) against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Ivermectin ›
- Rosuvastatin ›
- Aspirin ›
- Tirzepatide ›
- Docusate ›
- Valacyclovir ›
- Metformin ›
- Levothyroxine, Liothyronine ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Methotrexate ›
- Lisinopril ›
- Amoxicillin ›
- Azithromycin ›
- Doxycycline ›
- Acyclovir ›
- Methylene Blue ›
- Candesartan Cilexetil ›
- Amoxicillin, Clavulanate Potassium ›
- Acetylsalicylic Acid ›
- Aluminum Hydroxide, Aspirin, Magnesium Hydroxide ›
- Insulin Degludec, Liraglutide ›
- Calcium Oxybate, Magnesium Oxybate, Potassium Oxybate, Sodium Oxybate ›
- Atenolol, Chlorthalidone ›
- Ezetimibe ›
- Cephalexin ›
- Avatrombopag Maleate ›
- Cyclopentolate ›
- Bendroflumethiazide, Rauwolfia Serpentina ›
- Levodopa ›
- Enalapril Maleate ›
- Canagliflozin, Metformin ›
- Aspirin, Butalbital ›
- Thyroid Hormone ›
- Carbidopa, Levodopa ›
- Daunorubicin, Cytarabine ›
- Mannitol ›
- Bismuth Subcarbonate, Calcium Carbonate, Opium ›
- Ceftolozane Sulfate, Tazobactam Sodium ›
- Alginic Acid, Aluminum Hydroxide ›
- Acarbose ›
- Spironolactone ›
- Cytomegalovirus Immune Globulin ›
- Hydrocortisone, Clioquinol, Pramoxine ›
- Efgartigimod Alfa-fcab ›
- Saxagliptin, Metformin Xr ›
- Charcoal (otc Drug) ›
- Atenolol ›
- Peginterferon Alfa-2a, Ribavirin ›
- Atropine Methyl Nitrate, Digestive Enzymes ›
- Sodium Bicarbonate (otc Drug) ›
- Aminolevulinic Acid Hydrochloride ›
- Magnesium Hydroxide (otc Drug) ›
- Insulin Aspart, Insulin Degludec ›
- Levothyroxine Sodium ›
- Alpha-1 Proteinase Inhibitor ›
- Articaine, Epinephrine ›
Showing the 60 most looked-up of 1,779 medications checked with no known interaction — see the full Cannabidiol (cbd) list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Belladonna, Ergotamine, Phenobarbital Is Linked to Lower Levels of 7 Nutrients
Natural Medicines records Belladonna, Ergotamine, Phenobarbital as a medicine that can lower these. This is not an interaction with Cannabidiol (cbd) — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Belladonna, Ergotamine, Phenobarbital nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Cannabidiol (cbd) and Belladonna, Ergotamine, Phenobarbital Together: Common Questions
Can you take Cannabidiol (cbd) with Belladonna, Ergotamine, Phenobarbital?
Why are there 5 interactions listed for Cannabidiol (cbd) and Belladonna, Ergotamine, Phenobarbital?
How serious is the Cannabidiol (cbd) and Belladonna, Ergotamine, Phenobarbital interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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