Thiamine-Induced Cardiac Arrest: Case Reports and Clinical Evidence
Yes, there are documented case reports of cardiac arrest and fatal anaphylactic reactions following intravenous thiamine administration, though these events are rare. The FDA drug label explicitly warns that "deaths have resulted from IV or IM administration of thiamine" due to serious hypersensitivity/anaphylactic reactions 1.
Documented Cases
The literature contains verified case reports of thiamine-induced anaphylaxis leading to cardiovascular collapse:
A 1992 case report documented anaphylaxis from IV thiamine administration, representing the first reported instance in US literature since 1946 2. However, the authors noted that cases have been reported "with some regularity in the non-US literature," suggesting this is an underrecognized phenomenon in American medical practice 2.
The FDA adverse reaction database documents "collapse and death" following thiamine injection 1, along with life-threatening reactions including cyanosis, pulmonary edema, angioneurotic edema, and gastrointestinal hemorrhage 1.
Critical Safety Warnings
The FDA mandates specific precautions before IV thiamine administration 1:
- Skin testing is required for patients suspected of drug allergies or previous thiamine reactions: administer one-hundredth of the dose intradermally and observe for 30 minutes 1
- If no reaction occurs, give the full dose but observe for at least 30 minutes post-injection 1
- Be prepared to treat anaphylaxis with a patent airway, epinephrine, oxygen, vasopressors, steroids, and antihistamines immediately available 1
Important Caveat
The FDA acknowledges that "routine testing for hypersensitivity, in many cases, may not detect hypersensitivity" 1, meaning even with precautions, reactions can still occur unpredictably.
Clinical Context
Despite these documented risks, thiamine remains relatively safe given the large number of patients treated without adverse effects 2. The drug is indicated for rapid restoration of thiamine in life-threatening conditions including:
- Wernicke's encephalopathy
- Cardiovascular beriberi (Shoshin beriberi)
- Prevention of heart failure when giving IV dextrose to thiamine-deficient patients 1
The assumption that thiamine is completely innocuous is not accurate 2, and clinicians must balance the life-saving benefits in thiamine deficiency against the rare but potentially fatal risk of anaphylaxis, particularly with repeated administration 1.
Risk Mitigation Strategy
When administering IV thiamine:
- Always have resuscitation equipment immediately available
- Administer slowly (rapid IV push increases anaphylaxis risk)
- Monitor continuously for 30 minutes after administration
- Consider skin testing in patients with drug allergy history
- Be especially cautious with repeat dosing, as hypersensitivity risk increases with repeated administration 1