Wild Lettuce - Acetaminophen, Doxylamine, Pseudoephedrine Interaction
Herbal: Wild Lettuce
Also Known As: Lactuca virosa, Acrid Lettuce, Allubbyne, Bitter Lettuce, German Lactucarium, Green Endive, Lactucarium, Laitue Amère, Laitue à Opium, Laitue Sauvage, Laitue Scariole, Laitue Serriole, Laitue Vireuse, Lechuga Silvestre, Lettuce Opium, Poison Lettuce
Drug: Acetaminophen, Doxylamine, Pseudoephedrine
Brand names:
Ex Strength Tylenol Sinus Nighttime

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Feb 21, 2023
Interaction Details
Acetaminophen, Doxylamine, Pseudoephedrine is classified as belonging to the following category: Anticholinergic Drugs
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug. If it does, it appears to be in very low amounts. Nevertheless, there have been case reports of individuals consuming large amounts of wild lettuce experiencing anticholinergic-related side effects, such as constipation, dry mouth, dizziness, and sweating. Therefore, if you are already taking a drug with anticholinergic effects, you should be cautious about combining it with wild lettuce as the risk of side effects may be increased.
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
Pharmacist Analysis
It is unlikely that wild lettuce contains appreciable amounts of hyoscyamine to make a clinical impact in most individuals. However, case reports have documented individuals showcasing anticholinergic side effects after consuming very large quantities. Due to this, I would recommend caution if you are already taking anticholinergic drugs or drugs that have anticholinergic effects (such as tricyclic antidepressants, some antipsychotics, some antihistamines, etc...).
- Dr. Brian Staiger, PharmDWild Lettuce Overview

Wild Lettuce - More Interactions
Wild Lettuce interacts with 390 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.