Calamus - Claritin (Loratadine) Interaction
Herbal: Calamus
Also Known As: Acorus calamus, Acore Calame, Acore Odorant, Acore Olorant, Acore Roseau, Acorus Roseau, Aruna, Bach, Bajai, Baje, Belle-Angélique, Bhutanashini, Cálamo, Calamo Aromatic, Calamus Root, Cinnamon Sedge, Flag Root, Flagroot, Gladdon, Golomi, Grass-Leaf Sweetflag, Grass Myrtle, Ka
Drug: Loratadine
Brand names:
Claritin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Loratadine is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, taking calamus with drugs metabolized by CYP3A4 might increase drug levels and potentially increase the risk of adverse effects.
In vitro research shows that calamus extract inhibits CYP3A4 enzyme.
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
- Pandit S, Mukherjee PK, Ponnusankar S, Venkatesh M, Srikanth N. Metabolism mediated interaction of a-asarone and Acorus calamus with CYP3A4 and CYP2D6. Fitoterapia 2011;82(3):369-74.
Calamus Overview

Loratadine Overview
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Loratadine is used to temporarily relieve the symptoms of hay fever (allergy to pollen, dust, or other substances in the air) and other allergies. These symptoms include sneezing, runny nose, and itchy eyes, nose, or throat. Loratadine is also used to treat itching and redness caused by hives. However, loratadine does not prevent hives or other allergic skin reactions. Loratadine is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.
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Loratadine is also available in combination with pseudoephedrine (Sudafed, others). This monograph only includes information about the use of loratadine alone. If you are taking the loratadine and pseudoephedrine combination product, read the information on the package label or ask your doctor or pharmacist for more information.
Calamus - More Interactions
Calamus interacts with 1091 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.