Generic name: thiamine (vitamin B1) (THIGH a min)
Brand name: Vitamin B1
Dosage forms: injectable solution (100 mg/mL); oral tablet (100 mg; 250 mg; 50 mg)
Drug class: Vitamins
Thiamine is vitamin B1. Thiamine is found in foods such as cereals, whole grains, meat, nuts, beans, and peas. Thiamine is important in the breakdown of carbohydrates from foods into products needed by the body.
Thiamine is used to treat or prevent vitamin B1 deficiency. Thiamine injection is used to treat beriberi, a serious condition caused by prolonged lack of vitamin B1.
Thiamine taken by mouth (oral) is available without a prescription. Injectable thiamine must be given by a healthcare professional.
Thiamine may also be used for purposes not listed in this medication guide.
Warnings
You should not use thiamine if you have ever had an allergic reaction to it.
Ask a doctor or pharmacist before taking thiamine 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 thiamine, tell your doctor if you have kidney disease.
Thiamine 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 thiamine if you have ever had an allergic reaction to it.
Ask a doctor or pharmacist if it is safe for you to take this medicine 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 thiamine, tell your doctor if you have kidney disease.
Thiamine is not expected to harm an unborn baby. Your thiamine dose needs may be different during pregnancy. Do not take thiamine 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 thiamine?
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 thiamine 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.
Thiamine 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 thiamine?
Follow your doctor's instructions about any restrictions on food, beverages, or activity.
Thiamine 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 thiamine 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.
Thiamine dosing information
Usual Adult Dose for Beriberi:
10 to 20 mg IM three times daily for up to 2 weeks. Thereafter, use an oral therapeutic multivitamin preparation containing 5 to 10 mg thiamine daily for one month. A complete and balanced diet should follow.
Neuritis of pregnancy:
If vomiting severe to preclude oral therapy, give 5 to 10 mg IM daily.
'Wet' with myocardial failure:
Treat as an emergency cardiac condition. Thiamine is administered slowly by the IV route.
Usual Adult Dose for Thiamine Deficiency:
If dextrose administered: to patients with marginal thiamine status, give 100 mg in each of the first few liters of IV fluid to avoid precipitating heart failure.
Usual Adult Dose for Vitamin/Mineral Supplementation:
50 to 100 mg orally once a day
Usual Adult Dose for Wernicke's Encephalopathy:
100 mg IV as an initial dose followed by 50 to 100 mg/day IM or IV until the patient is on a regular, balanced, diet.
Usual Pediatric Dose for Beriberi:
10 to 25 mg IM or IV daily (if critically ill), or 10 to 50 mg orally every day for 2 weeks, then 5 to 10 mg orally daily for 1 month. If collapse occurs: 25 mg IV. Administer with caution.
Usual Pediatric Dose for Thiamine Deficiency:
If dextrose administered: to patients with marginal thiamine status, give 100 mg in each of the first few liters of IV fluid to avoid precipitating heart failure.
Usual Pediatric Dose for Vitamin/Mineral Supplementation:
Infants: 0.3 to 0.5 mg orally once a day; children: 0.5 to 1 mg orally once a day.
What other drugs will affect thiamine?
There may be other drugs that can interact with thiamine. 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.