Vitamin B1 Side Effects

Generic name: thiamine

Medically reviewed by Drugs.com. Last updated on Jul 17, 2023.

Note: This document contains side effect information about thiamine. Some dosage forms listed on this page may not apply to the brand name Vitamin B1.

Applies to thiamine: solution, tablet.

Serious side effects of Vitamin B1

Along with its needed effects, thiamine (the active ingredient contained in Vitamin B1) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking thiamine:

Rare

- Soon after receiving injection only

Coughing
difficulty in swallowing
hives
itching of skin
swelling of face, lips, or eyelids
wheezing or difficulty in breathing

For Healthcare Professionals

Applies to thiamine: compounding powder, injectable solution, oral tablet.

Local

Local side effects have included tenderness and induration at the injection site following intramuscular use.^[Ref]

Hypersensitivity

Hypersensitivity side effects have included a feeling of warmth, pruritus, urticaria, weakness, sweating, nausea, restlessness, tightness of the throat, angioneurotic edema, cyanosis, pulmonary edema, and hemorrhage into the gastrointestinal tract. Anaphylaxis has been reported, especially after repeated injection. Collapse and death have also been reported.^[Ref]