Can Thiamine Be Continued in a Patient with New Onset Seizures?
Yes, thiamine should absolutely be continued and may even be beneficial in patients with new onset seizures, as thiamine deficiency itself can provoke seizures and there is no contraindication to its use in this setting.
Rationale for Continuing Thiamine
Thiamine Deficiency Can Cause Seizures
- Thiamine deficiency may directly provoke epileptic phenomena in patients with subclinical predisposition for seizures, with 16 of 50 consecutive neurological patients with thiamine deficiency showing epileptic or epileptiform manifestations 1
- Animal studies demonstrate that chronic thiamine administration (200 mg/kg) increases seizure threshold for both clonic and tonic seizures, suggesting anticonvulsant properties 2
- Thiamine serves as a cofactor for enzymes involved in brain function and neurotransmitter biosynthesis, with deficiency reducing seizure threshold 2
Standard Seizure Workup Supports Thiamine Use
The 2004 Annals of Emergency Medicine clinical policy for new onset seizures recommends checking glucose and sodium levels as Level B recommendations, but does not mention thiamine as a contraindication 3. The guidelines focus on:
- Serum glucose and sodium determination in first-time seizure patients who have returned to baseline 3
- Pregnancy testing for women of childbearing age 3
- Head CT scanning when feasible, with deferred outpatient imaging acceptable when reliable follow-up exists 3
Notably, there is no mention of discontinuing vitamins or thiamine in seizure patients, suggesting no recognized contraindication 3
Clinical Scenarios Where Thiamine Is Particularly Important
High-Risk Populations
- Patients with alcohol use disorders require routine thiamine supplementation to prevent Wernicke's encephalopathy and Korsakoff psychosis, regardless of seizure history 3
- For severe alcoholic hepatitis patients, thiamine should be administered before commencing parenteral nutrition to prevent Wernicke's encephalopathy or refeeding syndrome 3
- Patients with malnutrition, prolonged vomiting, or poor dietary intake should receive 200-300 mg daily 4
Dosing in Seizure Patients
- For suspected thiamine deficiency with neurological symptoms (including seizures), use 100-300 mg IV daily for 3-4 days 3, 5
- If Wernicke encephalopathy is suspected, escalate to 500 mg IV three times daily 5
- Thiamine must be given before glucose-containing IV fluids to avoid precipitating acute deficiency 5, 6
Safety Profile
- Thiamine has no established upper limit for toxicity, with excess excreted in urine 5, 6, 4
- High IV doses rarely cause anaphylaxis 5, 6, 4
- Doses exceeding 400 mg may induce mild nausea, anorexia, and mild ataxia 5, 6, 4
- Treatment should never be delayed waiting for laboratory confirmation, as thiamine reserves can be depleted within 20 days of inadequate intake 5
Potential Synergistic Benefits
- Combination of sub-effective doses of thiamine (100 mg/kg) with diazepam (0.1 mg/kg) significantly increased seizure threshold and enhanced anticonvulsant effects in animal models 2
- This suggests thiamine may be considered as potential add-on treatment in epileptic patients, whether thiamine-deficient or not 2
Critical Pitfall to Avoid
Do not discontinue thiamine in seizure patients based on unfounded concerns. The evidence shows thiamine deficiency can cause seizures 1, thiamine has anticonvulsant properties 2, and there is no contraindication mentioned in seizure management guidelines 3. The risk of withholding thiamine (precipitating Wernicke's encephalopathy, worsening seizure threshold) far outweighs any theoretical concern about continuing it.