Description
Thiamine (vitamin B₁) is a water-soluble B vitamin required for carbohydrate metabolism and normal nerve function. The 100 mg tablet is often used for treating or preventing thiamine deficiency (e.g. in malnutrition, alcoholism, malabsorption, certain metabolic conditions). 

 Prescription
In many countries, thiamine is available over the counter (as a vitamin supplement). However, in therapeutic (high-dose) use, it may be dispensed under medical supervision or prescription depending on local regulations. 

Therapeutic Category
Vitamin / Nutritional supplement (Water-soluble vitamin)
Used therapeutically to correct vitamin B₁ deficiency (e.g. beriberi, Wernicke’s encephalopathy). 

Active Ingredients / Composition

• Active: Thiamine hydrochloride equivalent to 100 mg of thiamine per tablet.
• Excipients will vary by brand (fillers, binders, coatings) — not typically disclosed in basic sources.

Vitamins
Yes — this is itself a vitamin (Vitamin B₁). No additional vitamins are inherently in the formulation (unless it’s a multivitamin combination product).

Minerals
None (not a source of dietary minerals).

Variant
Oral solid tablet, immediate-release (non-extended, unless a special sustained or slow release form).
Available in different strengths (e.g. 50 mg, 100 mg) and sometimes in combination with other B vitamins. 

Consume Type
Oral — the tablet is swallowed (with or without food). 

Directions / Usage

• Typical dose for mild deficiency: 25 mg to 100 mg once daily.
• For severe deficiency (or therapeutic use): 100 mg up to 2–3 times daily (depending on the condition). 
• Continue therapy until deficiency is corrected; sometimes maintenance dosing may be lower.
  Tablets can be taken with or without food.

Common Side Effects
Thiamine is generally well tolerated. Side effects are rare, but may include:

• Flushing
• Itching or hives
• Sweating
• Weakness
• Nausea
• Restlessness
• Allergic reactions (rare)
  

Package Type
Tablets are usually packaged in blister packs or bottles. The exact size (number of tablets per pack) depends on the manufacturer.

Storage Advice

• Store at room temperature, away from excessive heat and moisture. 
• Keep in original container, tightly closed.
  Protect from light.
• Keep out of reach of children.
  

Safety Advice / Precautions

• If allergic to thiamine or any excipient, do not use. 
• Use caution in patients with metabolic conditions, such as those with severe renal or hepatic impairment, especially if combining with other therapies.
• Thiamine should not substitute for other treatments unless deficiency is the cause.
• In alcoholics or malnutrition, other nutritional deficiencies may coexist — comprehensive assessment is needed.
• During pregnancy and lactation, thiamine is generally considered safe and is often recommended when deficiency is suspected, but dosing should be under medical guidance. 
• Overdose is unlikely to cause serious harm (because it’s water-soluble), but as with any supplement, avoid excessive dosing beyond recommended amounts.
  

Product Substitutes
Other thiamine 100 mg tablets (generic brands)
Thiamine in multivitamin / B-complex formulations
Lower dose thiamine tablets (e.g. 50 mg) depending on need

Manufacturer / Marketer
This depends entirely on the brand in your country. Many pharmaceutical companies produce or market thiamine tablets under various brand names. (Not specified in the sources I searched.)

 Country of Origin
Similarly, the country of origin depends on the manufacturer’s location for the specific brand you have. Thiamine as a generic is widely produced in many countries.