Sweet Clover - Urobiotic (Oxytetracycline, Phenazopyridine, Sulfamethizole) Interaction
Herbal: Sweet Clover
Also Known As: Melilotus officinalis, Angipars, Casse Lunettes, Common Melilot, Couronne Royale, Field Melilot, Hart's Tree, Hay Flower, Herbe aux Puces, King's Clover, Luzerne Bâtarde, Melilot, Mélilot, Mélilot des Champs, Mélilot Commun, Mélilot Jaune, Mélilot Officinal
Drug: Oxytetracycline, Phenazopyridine, Sulfamethizole
Brand names:
Urobiotic

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Oxytetracycline, Phenazopyridine, Sulfamethizole is classified as belonging to the following category: Hepatotoxic Drugs
Theoretically, concomitant use of sweet clover with hepatoxic drugs might increase the risk of hepatotoxicity.
Orally, large amounts of sweet clover can cause transient liver injury in susceptible individuals, possibly due to coumarin content. In one case report, a patient with multiple sclerosis developed jaundiced palms and a slight elevation in serum alanine aminotransferase (ALT) after taking sweet clover containing coumarin 10 mg daily for 3 years. Two weeks after starting therapy with subcutaneous interferon (IFN)-beta 1b, aspartate transaminase (AST) and ALT levels increased to 7 and 17 times the upper limit of normal, respectively. Levels normalized after discontinuation of both products. Subsequent use of IFN-beta 1a alone, without sweet clover, resulted in only a very slight increase in AST.
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
- Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
- Tamura S, Warabi Y, Matsubara S. Severe liver dysfunction possibly caused by the combination of interferon beta-1b therapy and melilot (sweet clover) supplement. J Clin Pharm Ther 2012;37(6):724-5.
Sweet Clover Overview

Sweet Clover - More Interactions
Sweet Clover 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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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.
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Drug descriptions are provided by MedlinePlus.