Primidone
Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Primidone is an anticonvulsant used for seizure disorders and commonly used off-label for essential tremor. It is metabolized partly to phenobarbital and phenylethylmalonamide, so sedation, ataxia, dependence-related concerns, and enzyme-induction effects can occur. Long-term therapy can contribute to vitamin D, calcium, and folate problems through phenobarbital-like enzyme induction.
Exploratory record, not a reviewed medical publication.
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This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Primidone is an anticonvulsant used for seizure disorders and commonly used off-label for essential tremor. NutriStack rates the supporting evidence as strong. Common adult dosing is For seizures, start very low, often 100-125 mg at bedtime or 50 mg/day in sensitive patients, then titrate gradually. Common maintenance is 250 mg three or four times daily; doses should not exceed 500 mg four times daily., though a prescriber sets the actual dose. With long-term use it can deplete vitamin d, calcium, folate. This profile indexes 3 sources.
The bottom line
Evidence rating strong. Most-documented uses: treatment of generalized tonic-clonic and focal seizures, adjunctive antiseizure therapy, reduction of essential tremor symptoms when prescribed by a clinician. 3 sources indexed (2004–2025), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Primidone and its active metabolites reduce neuronal excitability through barbiturate-like enhancement of GABAergic inhibition and other antiseizure effects. Phenobarbital formation contributes both efficacy and adverse effects, including sedation and hepatic enzyme induction. Enzyme induction can accelerate vitamin D catabolism and alter folate metabolism, contributing to bone and hematologic complications during chronic use.1,3
Dosing & protocol.
May be taken with food to reduce nausea. Slow titration reduces acute sedation, dizziness, and ataxia.
What it depletes.
Nutrients this medication can lower over time, and what to replace.
Vitamin D
SignificantPrimidone's phenobarbital metabolite and enzyme-inducing effects accelerate vitamin D catabolism.
Calcium
ModerateLower vitamin D activity reduces intestinal calcium absorption and can contribute to bone loss.
Folate
ModerateChronic older anticonvulsant therapy can lower folate status and contribute to megaloblastic anemia.
Full safety detail.
Side effects
- Sedation
- Dizziness
- Ataxia
- Nausea
- Vomiting
- Diplopia
- Cognitive slowing
- Mood changes
- Megaloblastic anemia
- Bone loss or osteomalacia with chronic use
- Rash or hypersensitivity
- Suicidal thoughts or behavior warning for antiepileptic drugs
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Reviews & position papers
2- 1Evidence-based guideline update: treatment of essential tremorZesiewicz TA et al. · Neurology · 2011
Guideline identifies primidone as an established therapy for essential tremor.
- 2Antiepileptics and bone healthPack AM · Current Opinion in Neurology · 2004
Review links older enzyme-inducing antiseizure drugs with altered vitamin D metabolism and bone disease.
Reference material
1- 3PRIMIDONE tablets, US Prescribing InformationURLU.S. National Library of Medicine · DailyMed · 2025
Labeling describes titration, maintenance dosing, maximum dosing, contraindications, and withdrawal seizure risk.
Common questions.
Quick answers about Primidone, drawn from the data on this page.
What is Primidone?
Primidone is an anticonvulsant used for seizure disorders and commonly used off-label for essential tremor. It is metabolized partly to phenobarbital and phenylethylmalonamide, so sedation, ataxia, dependence-related concerns, and enzyme-induction effects can occur. Long-term therapy can contribute to vitamin D, calcium, and folate problems through phenobarbital-like enzyme induction.
What is Primidone used for?
Commonly cited benefits of Primidone include: Treatment of generalized tonic-clonic and focal seizures; Adjunctive antiseizure therapy; Reduction of essential tremor symptoms when prescribed by a clinician. NutriStack rates the overall evidence as strong.
What is a typical dose of Primidone?
A typical adult dose of Primidone is For seizures, start very low, often 100-125 mg at bedtime or 50 mg/day in sensitive patients, then titrate gradually. Common maintenance is 250 mg three or four times daily; doses should not exceed 500 mg four times daily.. The commonly recommended form is Oral tablet with slow titration. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Primidone?
Reported side effects include sedation, dizziness, ataxia, nausea, vomiting, diplopia. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Primidone?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Primidone in NutriStack.
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