The short answer
A harmful interaction between a verified single-plant Convolvulus product and phenytoin is not established. Reports involving a preparation called Shankhapushpi cannot automatically identify which ingredient caused the problem. Have the exact product reviewed before use.
What this answer covers
Convolvulus prostratus, including research under its scientific synonym C. pluricaulis, with phenytoin; a named Ayurvedic mixture is not automatically equivalent.
- Supplement or preparation
- Convolvulus prostratus
- Medication ingredient
- phenytoin
The clinical report concerns a preparation
Two patients lost seizure control while taking a product called Shankhapushpi, and subsequent animal experiments found reduced phenytoin activity with that preparation. The available original abstract does not establish that it was a verified single-plant Convolvulus product.
Single-plant animal evidence differs
A separate experiment used authenticated whole-plant aqueous extract and injected phenytoin in mice. The combination improved protection in an induced-seizure model. This does not prove human benefit or safety, but it prevents assigning every mixture result to the single plant.
A shared name is not enough
The botanical synonym in the animal paper maps to the same scientific species, but that does not identify all products sold under a traditional name. Bring the full ingredient label and preparation details to your pharmacist.
Protect established seizure control
There is no verified safe supplement dose or protective spacing interval from these studies. Keep phenytoin treatment coordinated with the prescriber and report any change in seizure frequency. Do not use an animal study as a reason to replace or reduce prescribed medicine.
Evidence and practical considerations
Absorption & effectiveness
A harmful interaction between a verified single-plant Convolvulus product and phenytoin is not established. Reports involving a preparation called Shankhapushpi cannot automatically identify which ingredient caused the problem. Have the exact product reviewed before use.
- Exact scope
- Convolvulus prostratus, including research under its scientific synonym C. pluricaulis, with phenytoin; a named Ayurvedic mixture is not automatically equivalent. with Oral phenytoin; free-acid and sodium-salt formulations are explicitly distinguished.
- Medication form and route
- oral
What remains uncertain
- No universal risk rate or dose interval is established. Specific original-source limitations and access status are documented.
Factors that may matter: Exact preparation and amount; Medication formulation and drug levels; Seizure history and other treatments.
Read the supporting source summaries
Source 1: Current U.S. regulatory labeling
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed oral phenytoin for supported seizure indications.
Labels name folic acid and St John’s wort as possible causes of lower phenytoin levels. Calcium-carbonate and magnesium-hydroxide antacids should not be taken simultaneously. Abrupt withdrawal can worsen seizures.
How this applies: Exact medication precautions with the formulation bridge explicitly retained.
A generic mineral is not every antacid salt. Free-acid and sodium formulations have different drug content; oral absorption findings do not apply to intravenous administration.
Source 2: Original clinical observations and animal experiments
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Two patients with unexpected seizure recurrence, followed by rat experiments.
Patients had low phenytoin levels and lost control; repeated coadministration also reduced levels and seizure protection in rats.
How this applies: A preparation-level signal cannot be assigned automatically to Convolvulus prostratus alone.
Original abstract does not authenticate a single-plant product. Full publisher text unavailable, so specific mixture ingredients are not asserted as verified.
Source 3: Original animal experiment
ijam.co.in · Source check Sep 10, 2026
Population: Small groups of albino mice.
The combination delayed induced convulsions more than phenytoin alone in the reported experiment.
How this applies: Contrary preparation-specific evidence, not a human treatment recommendation.
Animal model with injected medication; no drug-level or oral-absorption measurements. Reporting inconsistencies and small groups limit certainty.
Source 4: Authoritative botanical identity reference
powo.science.kew.org · Source check Sep 10, 2026
Population: Botanical nomenclature, not clinical subjects.
Kew treats Convolvulus pluricaulis as a synonym of Convolvulus prostratus.
How this applies: Permits the limited botanical-name bridge while preserving product uncertainty.
A nomenclatural relationship does not verify a bottle or establish that a named commercial mixture contains only this species.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Initial source-checked research draft with exact formulation limits, contrary evidence and source-access details. Clinical review not recorded. | |
| Research summary published |
Article revision: d1e9a9ebf9bcd7cc
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.