Indications
Nicotinic acid (Niacin) is a form of vitamin B3. In vitamin doses it prevents and treats niacin deficiency (pellagra, which causes skin rash, diarrhoea and confusion). In much larger doses, under medical supervision, it is used to lower high blood fats: it reduces LDL (bad) cholesterol and triglycerides and raises HDL (good) cholesterol, usually when other treatments are not suitable or not enough.
How It Works
The body uses niacin to make coenzymes (NAD and NADP) needed to turn food into energy. At high doses it reduces the release of fat from fat tissue and lowers the liver’s production of the particles that carry cholesterol and triglycerides in the blood.
Dosage and Administration
As a vitamin supplement, use as directed on the label (adults usually need about 14 to 16 mg a day from all sources). For high cholesterol, the dose is started low and increased slowly as prescribed by your doctor; extended-release tablets are usually taken once a day at bedtime after a low-fat snack and swallowed whole. Do not swap between immediate-release and extended-release forms on your own.
Interactions
Taking it with statins (for example Atorvastatin, Simvastatin) can raise the risk of muscle damage. It may increase the effect of blood pressure medicines and may affect blood sugar in people taking diabetes medicines. Bile acid binders such as Cholestyramine should be taken at least 4 to 6 hours apart. Alcohol and hot drinks can worsen flushing.
Contraindications
- Active liver disease or unexplained raised liver enzymes
- Active stomach or duodenal ulcer
- Active bleeding from an artery
- Allergy to nicotinic acid
Side Effects
Flushing (warmth, redness and itching of the face and body) is very common, especially at the start; it usually eases with time. Other effects include stomach upset, nausea, diarrhoea, headache, dizziness and raised blood sugar or uric acid (gout).
Get urgent medical help if you have yellow skin or eyes, dark urine, severe stomach pain, unexplained muscle pain or weakness with dark urine, fainting, fast or irregular heartbeat, or swelling of the face or trouble breathing.
Pregnancy and Lactation
Normal vitamin amounts are safe in pregnancy and breastfeeding. High doses used for cholesterol are not recommended during pregnancy or breastfeeding unless your doctor advises it.
Precautions and Warnings
High-dose treatment needs regular liver, blood sugar and lipid tests. Tell your doctor if you have diabetes, gout, liver or kidney disease, heart problems or drink alcohol heavily. Rising slowly from sitting or lying helps avoid dizziness. Do not replace prescribed tablets with over-the-counter niacin.
Overdose
Large overdoses may cause intense flushing, dizziness, vomiting, low blood pressure and liver damage. Seek medical help.
Therapeutic Class
Vitamin B3; lipid-modifying agent.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.