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Vitamin B1

Generic Name: thiamine (vitamin B1) (THIGH a min)
Brand Name: Vitamin B1

Medically reviewed by Drugs.com on Dec 3, 2018 – Written by Cerner Multum

What is Vitamin B1?

Vitamin B1 is vitamin B1. This medicine is found in foods such as cereals, whole grains, meat, nuts, beans, and peas. This medicine is important in the breakdown of carbohydrates from foods into products needed by the body.

Vitamin B1 is used to treat or prevent vitamin B1 deficiency. This medicine injection is used to treat beriberi, a serious condition caused by prolonged lack of vitamin B1.

Vitamin B1 taken by mouth (oral) is available without a prescription. Injectable this medicine must be given by a healthcare professional.

Vitamin B1 may also be used for purposes not listed in this medication guide.

Important Information

You should not use Vitamin B1 if you have ever had an allergic reaction to it.

Ask a doctor or pharmacist before taking Vitamin B1 if you have any medical conditions, if you take other medications or herbal products, or if you are allergic to any drugs or foods.

Before you receive injectable Vitamin B1, tell your doctor if you have kidney disease.

Vitamin B1 is only part of a complete program of treatment that may also include a special diet. It is very important to follow the diet plan created for you by your doctor or nutrition counselor. You should become very familiar with the list of foods you should eat or avoid to help control your condition.

Before taking this medicine

You should not use Vitamin B1 if you have ever had an allergic reaction to it.

Ask a doctor or pharmacist if it is safe for you to take Vitamin B1 if:

  • you have any other medical conditions;

  • you take other medications or herbal products; or

  • you are allergic to any drugs or foods.

To make sure you can safely receive injectable Vitamin B1, tell your doctor if you have kidney disease.

Vitamin B1 is not expected to harm an unborn baby. Your this medicine dose needs may be different during pregnancy. Do not take this medicine without medical advice if you are pregnant or plan to become pregnant.

It is not known whether thiamine passes into breast milk. Your dose needs may be different while you are nursing. Do not take thiamine without medical advice if you are breast-feeding a baby.

How should I take Vitamin B1?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Injectable Vitamin B1 is injected into a muscle. You may be shown how to use injections at home. Do not self-inject this medicine if you do not fully understand how to give the injection and properly dispose of used needles and syringes.

Do not use the injectable medication if it has changed colors or has particles in it. Call your doctor for a new prescription.

The recommended dietary allowance of thiamine increases with age. Follow your healthcare provider's instructions. You may also consult the National Academy of Sciences "Dietary Reference Intake" or the U.S. Department of Agriculture's "Dietary Reference Intake" (formerly "Recommended Daily Allowances" or RDA) listings for more information.

Vitamin B1 is only part of a complete program of treatment that may also include a special diet. It is very important to follow the diet plan created for you by your doctor or nutrition counselor. You should become very familiar with the list of foods you should eat or avoid to help control your condition.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Vitamin B1?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Vitamin B1 side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • blue colored lips;

  • chest pain, feeling short of breath;

  • black, bloody, or tarry stools; or

  • coughing up blood or vomit that looks like coffee grounds.

Less serious side effects may include:

  • nausea, tight feeling in your throat;

  • sweating, feeling warm;

  • mild rash or itching;

  • feeling restless; or

  • tenderness or a hard lump where a Vitamin B1 injection was given.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Vitamin B1?

There may be other drugs that can interact with Vitamin B1. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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