The short answer
Henbane containing active anticholinergic alkaloids may add to doxylamine side effects such as confusion, dry mouth, constipation or urinary retention. Do not add such a product without clinician review.
What this answer covers
Hyoscyamus niger preparations containing active tropane alkaloids.
- Supplement or preparation
- Hyoscyamus niger
- Medication ingredient
- doxylamine
Why the effects could add up
Doxylamine has anticholinergic or atropine-like effects. Active plant alkaloids can affect the same functions, making bowel, bladder, vision and mental-state symptoms relevant.
What the human report establishes
The original report describes plant poisoning in children, with anticholinergic symptoms. It supports concern about active plant material, but does not measure this medicine combination or the risk at an adult supplement dose.
The product identity matters
Plant part, extraction and concentration affect alkaloid exposure. A highly diluted product and an active herbal preparation cannot be assumed equivalent, and no reliable pair-specific dose threshold was established. OTC doxylamine sleep tablets and the delayed-release doxylamine/pyridoxine product for pregnancy nausea have different purposes and schedules. Their doxylamine effects are relevant, but the formulations are not interchangeable.
Act on symptoms rather than guessing a gap
Have the exact product checked before use. A short timing gap is not an established way to prevent overlapping effects. Seek urgent care for marked confusion, inability to urinate, severe abdominal swelling or pain, or a painful red eye with vision change.
Evidence and practical considerations
Side effects & toxicity
Conditional additive anticholinergic concern for active-alkaloid products, based on exact medication effects and original plant toxicity. No exact-pair event rate or safe dose established.
- Exact scope
- Hyoscyamus niger preparations containing active tropane alkaloids. with Oral doxylamine succinate sleep-aid tablets; delayed-release doxylamine/pyridoxine pregnancy product considered separately.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed doxylamine
Ask doctor/pharmacist before other sedatives or sleep aids; do not drive; use only at bedtime with a full night available.
How this applies: Exact doxylamine RxCUI 3642 IN, with stated salt/formulation/route bridge.
No exact supplement-combination incidence or validated protective spacing; salt, route and release form limits apply.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed doxylamine
Delayed-release doxylamine succinate/pyridoxine hydrochloride pregnancy product: somnolence due to doxylamine; CNS-depressant co-use not recommended, anticholinergic precautions.
How this applies: Exact doxylamine RxCUI 3642 IN, with stated salt/formulation/route bridge.
Same active ingredient, different formulation or combination. Product-specific results cannot be transferred as identical exposure.
Source 3: Original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Sixty-eight children admitted after Hyoscyamus niger poisoning.
Antimuscarinic toxicity included agitation, pupil changes and severe neurologic effects in some children.
How this applies: Interpreted for doxylamine only within the stated exact preparation and endpoint limits.
Pediatric plant poisoning, not an exact doxylamine co-use study or a normal adult supplement risk estimate.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Prepared exact doxylamine article with formulation-specific evidence and uncertainty. |
Article revision: 19e8227fbe5ff77a
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.