Ergot - Helidac (Bismuth Subsalicylate, Metronidazole, Tetracycline) Interaction
Herbal: Ergot
Also Known As: Claviceps purpurea, Cockspur Rye, Cornezuelo, Ergot de Seigle, Hornseed, Mai Jiao, Mother of Rye, Secale Cornutum, Smut Rye, Spurred Rye
Drug: Bismuth Subsalicylate, Metronidazole, Tetracycline
Brand names:
Helidac
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 18, 2025
Interaction Details
Bismuth Subsalicylate, Metronidazole, Tetracycline is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Inhibitors
Ergotamine, a constituent of ergot, is a substrate of cytochrome P450 3A4 (CYP3A4). Theoretically, drugs that inhibit CYP3A4 might increase the risk of ergot toxicity. Some of these drugs include amiodarone (Cordarone), clarithromycin (Biaxin), diltiazem (Cardizem), erythromycin (E-mycin, Erythrocin), indinavir (Crixivan), ritonavir (Norvir), saquinavir (Fortovase, Invirase), and many others.
Interaction Rating
Likelihood of Occurrence
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
References
- Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34.
Ergot Overview
Ergot is a fungal plant infection that most commonly grows on rye. Ergot contains ergolines, which are alkaloids that have various pharmacologic and toxic effects. A well-known illness from the Middle Ages, St. Anthony's Fire, was brought on by the widespread consumption of fungus-contaminated rye grain which caused ergot poisoning (ergotism). Ergot has been used medicinally for obstetric and gynecologic conditions, such as abnormally heavy bleeding at menstruation since ergot contains chemicals that can help reduce bleeding by causing a narrowing of the blood vessels. Due to the safety concerns of consuming ergot, its use is not recommended.
Bismuth Subsalicylate, Metronidazole, Tetracycline Overview
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Bismuth, metronidazole, and tetracycline is used along with other ulcer medications to treat duodenal ulcers. It is in a class of medications called antibacterial agents. It works by preventing the growth and spread of Helicobacter pylori bacteria, which often occurs with ulcers. Treating this infection keeps ulcers from coming back.
Ergot - More Interactions
Ergot interacts with 453 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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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
Drug descriptions are provided by MedlinePlus.
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In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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