Galanthus nivalis · PhytoNexus

01 Identity and provenance

Accepted binomial: Galanthus nivalis
Common names: Snowdrop
Family (APG IV): Amaryllidaceae
Part used: Bulb
Verification tier: Tier 2 · Verified Clinical columns reviewed and a source is on record.
Reviewer note (2026 audit): PMC11074532 (cholinergic crisis with normal cholinesterase) | PMC10049459 (galantamine cholinergic signalling review) | VERIFIED 2026 (batch 5) - synthetic analogue, application, interactions, side effects and references populated from retrieved primary/regulatory sources. Interactions labelled CLINICAL vs THEORETICAL. Marketed-formulation column intentionally blank. | DIAGNOSTIC

02 Constituent chemistry

Chemical class	Marker compound	Synthetic analogue in use
Amaryllidaceae alkaloids	Galantamine Bulb	Galantamine IS the derived drug (Razadyne, Nivalin) - now largely produced synthetically. Donepezil and rivastigmine are functional equivalents.

The analogue column is what makes the interaction reasoning tractable: where a constituent has a marketed structural counterpart, the counterpart's interaction profile is the starting hypothesis for the plant.

Looking up structures and physicochemical properties from PubChem…

03 Stated application

Reported activity: Source of galantamine for mild-to-moderate Alzheimer disease and vascular dementia - an AChE inhibitor that also allosterically modulates nicotinic receptors. Historically used in Bulgaria (Nivalin) for poliomyelitis and myasthenia gravis. Dioscorides recorded snowdrop as an antidote to stramonium poisoning, which is pharmacologically coherent: a cholinergic agent reversing anticholinergic delirium.
Reported adverse effects: Cholinergic adverse effects: nausea, vomiting, diarrhoea, bradycardia. Serious reported effects include gastrointestinal bleeding, liver injury and chest pain. DIAGNOSTIC TRAP: in a documented cholinergic crisis after a 264 mg galantamine overdose (89-year-old, 37 kg) the patient had pinpoint pupils, hypoxia and required intubation WHILE SERUM CHOLINESTERASE REMAINED NORMAL - a normal cholinesterase does not exclude the diagnosis. Animal data suggest a lethal threshold around 3-6 mg/kg.

04 Interaction matrix

Source column, verbatim: CLINICAL: ANTAGONISES non-depolarising neuromuscular blockers including tubocurarine - a documented and mechanistically direct interaction. Additive with other cholinesterase inhibitors and cholinergic agents; antagonised by anticholinergics. Cholinesterase inhibitors may lower HbA1c, so antidiabetic therapy may need adjustment.
Normalised onto 3 canonical drug classes below.

Curated from the reviewed source

Drug class	Severity	Mechanism type	Provenance	Expected effect
Anticholinergics Autonomic	4Contraindicated	PD-additive	curated A	Anticholinergic toxidrome: dry mouth, urinary retention, blurred vision, …	why ▾
Chemistry of this pair. These alkaloids inhibit acetylcholinesterase or agonise muscarinic receptors, raising synaptic acetylcholine. Class mechanism. Tropane alkaloids (atropine, hyoscine, hyoscyamine) are competitive muscarinic antagonists; added to prescribed anticholinergics, antihistamines or tricyclics the burden summates. Expected Anticholinergic toxidrome: dry mouth, urinary retention, blurred vision, tachycardia, delirium, hyperthermia. Management Calculate total anticholinergic burden. Avoid in older adults, prostatism and narrow-angle glaucoma. Onset rapid Evidence A - human data with a cited source Matched on “anticholinergics” Find evidence for this pair Map this mechanism
Cholinesterase inhibitors and cholinergic drugs Autonomic	4Contraindicated	PD-additive	curated A	Cholinergic crisis: bradycardia, bronchorrhoea, bronchospasm, miosis, sei…	why ▾
Chemistry of this pair. These alkaloids inhibit acetylcholinesterase or agonise muscarinic receptors, raising synaptic acetylcholine. Class mechanism. Physostigmine-, galantamine- and arecoline-type constituents inhibit acetylcholinesterase or agonise muscarinic receptors, adding to donepezil, rivastigmine, neostigmine or pyridostigmine. Expected Cholinergic crisis: bradycardia, bronchorrhoea, bronchospasm, miosis, seizures, weakness that mimics myasthenic crisis. Management Avoid. In suspected crisis distinguish cholinergic from myasthenic weakness before giving further anticholinesterase. Onset rapid Evidence A - human data with a cited source Matched on “cholinesterase inhibitors” Find evidence for this pair Map this mechanism
Antidiabetic drugs (insulin, sulfonylureas, biguanides, GLP-1, SGLT2) Endocrine	3Major	PD-additive	curated A	Symptomatic hypoglycaemia, sweating, tremor, confusion; severe events rep…	why ▾
Class mechanism. Hypoglycaemic botanicals act through insulin secretagogue, insulin-sensitising, alpha-glucosidase-inhibiting or glucose-transport routes. Added to a titrated pharmacological regimen the effects summate rather than plateau. Expected Symptomatic hypoglycaemia, sweating, tremor, confusion; severe events reported with insulin and sulfonylureas. Management Increase self-monitoring frequency for 2 weeks after starting or stopping. Anticipate a downward dose adjustment of insulin or sulfonylurea. Onset rapid Evidence A - human data with a cited source Matched on “antidiabetic” Find evidence for this pair Map this mechanism

Predicted from constituent chemistry

These edges are not clinical findings. Each one is a rule inference: a constituent class in this plant is known to act on a target that the drug class also acts on. They are shown because a blank cell reads as “safe”, and for a Tier 1 entry a blank cell only means “not yet looked at”. Treat them as a literature-search agenda, not as a warning.

Drug class	Severity	Mechanism type	Provenance	Expected effect
Narrow-therapeutic-index CYP3A4 substrates Pharmacokinetic	4Contraindicated	PK-CYP3A4	predicted D	Toxic accumulation or subtherapeutic failure of the co-prescribed drug, s…	why ▾
Chemistry of this pair. Alkaloidal bases have pH-dependent absorption and commonly interact with hepatic CYP isoenzymes and efflux transporters. Class mechanism. Furanocoumarins, bergamottin, piperine, glabridin and berberine inhibit CYP3A4; hyperforin, andrographolide and several diterpenes induce it through PXR. Because CYP3A4 handles roughly half of marketed drugs, the affected list is broad and the direction is product-specific. Expected Toxic accumulation or subtherapeutic failure of the co-prescribed drug, sometimes fatal for antiarrhythmics, immunosuppressants and oncology agents. Management Screen the full regimen for 3A4 substrates. Where the substrate has a narrow index, avoid rather than monitor. Onset unspecified Evidence D - in silico rule prediction only Find evidence for this pair Map this mechanism
Antacids, PPIs and H2 blockers Gastrointestinal	2Moderate	PK-absorption	predicted D	Reduced or erratic absorption of alkaloids; heartburn and reflux from pre…	why ▾
Chemistry of this pair. Alkaloidal bases have pH-dependent absorption and commonly interact with hepatic CYP isoenzymes and efflux transporters. Class mechanism. Gastric pH elevation alters the dissolution and ionisation of alkaloidal and enteric-coated botanical products; menthol- and peppermint-oil products lose their enteric protection at high pH and can be released prematurely. Expected Reduced or erratic absorption of alkaloids; heartburn and reflux from premature release of volatile-oil preparations. Management Separate administration by 2 hours. Avoid non-enteric peppermint oil in reflux disease. Onset unspecified Evidence D - in silico rule prediction only Find evidence for this pair Map this mechanism

05 Hazard register

misleading test or presentation - cholinergic crisis documented

06 Confusable material

No same-genus or shared-common-name entry in the corpus.

07 Mechanism map

Chemistry sorts to the left, pharmacology to the right. Dashed edges are predicted. Drag nodes, scroll to zoom, export at 3× for a figure.

species

chemical class

marker compound

drug class

expected effect

hazard

08 Open literature

Abstract-scoped query built from this binomial, its common names and its marker compounds, run live against Europe PMC, PubMed and OpenAlex, then ranked locally against an evidence hierarchy.

Checking openFDA spontaneous reports…

09 Isomechanistic neighbours

Species whose interaction profile overlaps this one, ranked by shared severity weight rather than by count — a shared contraindication counts for more than a shared minor signal. Practical use: these are the plants you should not stack with this one, because the mechanisms summate.

Species	Family	Shared classes	Jaccard
Duboisia myoporoides Corkwood	Solanaceae	4	0.57
Physostigma venenosum Calabar Bean	Fabaceae	4	0.44
Areca catechu Areca Nut	Arecaceae	4	0.80
Huperzia serrata Chinese Club Moss	Lycopodiaceae	4	0.67
Chondrodendron tomentosum Curare Vine	Menispermaceae	4	0.50
Atropa belladonna Belladonna	Solanaceae	3	0.43

10 References and notes

Source column: Heinrich M & Teoh HL. J Ethnopharmacol 2004;92:147-62

Heinrich M & Teoh HL. J Ethnopharmacol 2004

Heinrich M 2004 manual

92:147-62

manual

BibTeX for all 2 records

@article{HeinrichM2004,
  title = {Heinrich M & Teoh HL. J Ethnopharmacol 2004},
  author = {Heinrich M},
  year = {2004},
}

@article{anon,
  title = {92:147-62},
}

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