NIACOR
Clinical safety rating
cautionComprehensive clinical and safety monograph for NIACOR (NIACOR).
Comprehensive clinical and safety monograph for NIACOR (NIACOR).
Adjunct to diet for reduction of elevated total cholesterol, LDL-C, apo B, and triglyceride levels, and to increase HDL-C in primary hypercholesterolemia and mixed dyslipidemiaAdjunct to diet for reduction of risk of recurrent myocardial infarction in patients with coronary artery disease and hypercholesterolemiaAdjunct to diet for slowing progression of coronary atherosclerosisOff-label: treatment of pellagra (niacin deficiency)
Niacin (nicotinic acid) reduces VLDL and LDL synthesis by inhibiting lipolysis in adipose tissue, decreasing free fatty acid flux to the liver, and inhibiting hepatic triglyceride synthesis. It also increases HDL by reducing catabolism of apolipoprotein A-I.
| Metabolism | Hepatic metabolism via two pathways: conjugation with glycine to form nicotinuric acid (major, low-affinity high-capacity) and oxidation to N-methylnicotinamide and other metabolites (minor, high-affinity low-capacity). Enzymes involved: nicotinamide N-methyltransferase (NNMT) and aldehyde oxidase. |
| Excretion | Renal: 60-88% as unchanged drug and metabolites after oral administration; fecal: <2% |
| Half-life | 20–45 minutes for immediate-release niacin; terminal half-life of main metabolites (nicotinuric acid) is approximately 1.5–4 hours; short half-life necessitates multiple daily dosing for lipid effects |
| Protein binding | <20% bound to albumin; minimal binding to other plasma proteins |
| Volume of Distribution | 0.5–0.7 L/kg; indicates distribution into total body water and some tissue binding |
| Bioavailability | Oral immediate-release: 60–76% (variable due to first-pass metabolism); sustained-release: lower bioavailability (50–60%) due to increased presystemic metabolism |
| Onset of Action | Oral: 15–30 minutes for vasodilation/flushing; lipid-lowering effects require several days to weeks of chronic dosing |
| Duration of Action | Immediate-release: flushing lasts 0.5–2 hours; lipid effects persist with continued dosing; sustained-release formulations extend duration to 8–12 hours |
| Molecular Weight | 123.11 |
Initial: 250 mg orally once daily after evening meal; titrate up by 250–500 mg/day every 2–4 weeks. Maintenance: 1–2 g/day in divided doses (2–3 times daily). Maximum: 6 g/day.
| Dosage form | TABLET |
| Renal impairment | No specific adjustment recommended; use caution in severe renal impairment (CrCl <30 mL/min) due to potential accumulation; consider reducing dose or prolonging interval. |
| Liver impairment | Contraindicated in Child-Pugh class B and C; use with caution in mild impairment (Child-Pugh A) with dose reduction of 50% initially. |
| Pediatric use | For hyperlipidemia (off-label): Initial 50–100 mg/kg/day orally divided into 2–3 doses; titrate over 4–6 weeks up to 200–300 mg/kg/day; maximum 6 g/day. Not recommended in children <2 years. |
| Geriatric use | Start at lowest dose (250 mg daily); titrate slowly due to increased risk of flushing, hypotension, and hepatotoxicity; monitor liver function and glucose closely. |
| 1st trimester | Use only if clearly needed; avoid high doses due to potential teratogenicity in animal studies. |
| 2nd trimester | Use with caution; may cause maternal flushing and potential for fetal hypoxia. |
| 3rd trimester | Avoid near term due to risk of maternal hypotension and potential fetal distress. |
Clinical note
Comprehensive clinical and safety monograph for NIACOR (NIACOR).
| Placental transfer | Niacin crosses the placenta; limited data suggest minimal transfer at therapeutic doses. |
| Breastfeeding | Niacin is excreted into breast milk in small amounts. At high doses, may cause flushing and gastrointestinal disturbances in the infant. Monitor infant for adverse effects. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | FDA Pregnancy Category C. Niacin is not recommended for use in pregnant women due to potential fetal harm, though no well-controlled studies exist. In animal studies, high doses have caused fetal abnormalities. First trimester: Avoid use due to theoretical risk of teratogenicity. Second and third trimesters: Use only if clearly needed, as niacin can cause vasodilation and potential hypotension, which may reduce uteroplacental perfusion. |
| Fetal Monitoring | Monitor maternal liver function tests (LFTs), serum glucose, uric acid, and lipid profile regularly. In pregnancy, monitor for signs of hepatotoxicity, hyperglycemia, and hypotension. Fetal monitoring includes assessment of growth and well-being via ultrasound and non-stress tests if prolonged use occurs. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies have not shown impaired fertility at therapeutic doses. However, extreme hypertriglyceridemia (an indication for niacin) may be associated with infertility, which improves with treatment. |
■ FDA Black Box Warning
None.
| Serious Effects |
Active liver diseaseSignificant or unexplained hepatic dysfunctionActive peptic ulcer diseaseArterial bleeding
| Precautions | Hepatotoxicity: elevated liver enzymes, hepatitis; discontinue if persistent elevations occur, Flushing: prostaglandin-mediated, can be reduced by taking aspirin prior; tolerance develops, Hyperuricemia: may precipitate gout, Hyperglycemia: may increase blood glucose; use with caution in diabetes, Peptic ulcer disease: reactivation may occur, Hypotension: can occur, especially with vasoactive drugs |
| Food/Dietary | Avoid high-fat meals as they may increase risk of flushing. Take with low-fat snack. Alcohol and hot drinks can exacerbate flushing. |
| Clinical Pearls | Niacor (niacin) can cause profound flushing, which may be mitigated by taking aspirin 30 minutes prior or using extended-release formulations. Monitor liver function and blood glucose, as niacin can elevate transaminases and worsen glycemic control. Patients with gout may experience increased uric acid levels. |
| Patient Advice | Take with food to reduce stomach upset. · Do not crush or chew extended-release tablets. · Flushing is common and may decrease with continued use. · Avoid alcohol and hot beverages near dosing time to reduce flushing. · Report unexplained muscle pain, tenderness, or weakness. · Monitor blood sugar if diabetic. · Do not substitute with dietary supplements without doctor approval. |
Loading safety data…