Thiamine (Vitamin B-1) (By mouth)

Thiamine (THYE-a-min)

Thiamine, another name for Vitamin B-1, is used to treat thiamine-deficiency (not enough thiamine in the body).

Brand Name(s):

Optimum Vitamin B-1, Sundown Naturals B1

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to thiamine (Vitamin B-1).

How to Use This Medicine:

Tablet, Capsule, Liquid

  • Your doctor will tell you how much and when to take your medicine. Keep all medicine away from children.
  • You may take your medicine with or without food.
  • Measure your oral liquid medicine using a marked measuring spoon or medicine cup.

If a dose is missed:

  • Take the missed dose as soon as possible.
  • Skip the missed dose if it is almost time for your next dose.
  • You should not use two doses at the same time.
  • Missing a dose is generally not a cause for concern.

How to Store and Dispose of This Medicine:

  • Store the tablets at room temperature in a closed container. Keep away from heat, moisture, and direct light.
  • Store the oral liquid at room temperature, away from heat and light. Do not freeze.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Follow your doctor's orders if he or she has given you a special diet.

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you become pregnant.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Itching or trouble breathing
  • Swelling of face, lips or eyelids

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088


Last Updated: 9/6/2024

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