Nicotinamide
Vitamins
Vitamins
A form of vitamin B3 used to treat pellagra. Unlike nicotinic acid, it does not cause flushing and does not lower cholesterol.
Also called: niacinamide, vitamin B3
Quick facts
- Group
- Vitamins
- Target
- Precursor of NAD and NADP, the coenzymes of oxidation–reduction reactions
- Used for
- Pellagra
- Key effects
- Usually well tolerated · Stomach upset
- Monitor
- Skin lesions
- ATC
- A11HA01
No doses: the clinician sets them by the current guideline.
Mechanism of action
Nicotinamide is the amide form of niacin (vitamin B3). Cells use it to build NAD and NADP, which carry electrons in energy production and in many other reactions. Deficiency of niacin or of its precursor tryptophan causes pellagra: sore skin on sun-exposed areas, diarrhoea and confusion. Nicotinamide does not act on the niacin receptor of fat cells, so it has neither the flushing nor the lipid effects of nicotinic acid.
- Nicotinamide is built into NAD and NADP
- NAD/NADP carry electrons in energy metabolism
- Skin, gut and brain recover in pellagra
Indications
- Pellagra (niacin deficiency) Pellagra (niacin deficiency) →
Adverse effects
Common
- Usually well tolerated; no flushing
- Stomach upset
Contraindications
- Hypersensitivity to the product
- Caution at high intakes with liver disease, diabetes or peptic ulcer
Key interactions
- Isoniazid
- Can cause pellagra by interfering with niacin; nicotinamide replaces it
- Alcohol
- Heavy drinking is a major cause of pellagra
What is monitored
- Skin lesions, diarrhoea and mental state in pellagra
Pregnancy and breastfeeding
Niacin is needed in pregnancy; replacement amounts are used when there is deficiency.
Nursing care
- Look for pellagra in people with alcohol dependence, malabsorption, carcinoid syndrome or isoniazid treatment.
- Protect skin lesions from the sun and watch them for infection.
- Explain that nicotinamide and nicotinic acid are not interchangeable for cholesterol.
Pharmacokinetics
- Absorption
- Absorbed by mouth; water-soluble and not stored in large amounts
Test yourself
Think of the answer, then tap the question to see it.
What are the main features of pellagra?
Dermatitis on sun-exposed skin, diarrhoea and confusion (dementia); untreated, death.
How does nicotinamide differ from nicotinic acid?
Nicotinamide treats deficiency but causes no flushing and has no lipid-lowering effect.
Which antitubercular drug can cause pellagra?
Isoniazid.
Connections
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Pellagra: MedlinePlus Medical Encyclopedia (MedlinePlus (U.S. National Library of Medicine), 2026); Niacin: MedlinePlus Medical Encyclopedia (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.