As we journey through the water soluble vitamins, lets focus on Niacin (Vitamin B-3) which is available both as an extended release prescription product, as well as over the counter in our vitamin aisles.
Dietary sources: meat , fish, legumes, whole grains
Function: oxidation reduction reactions it is an essential co-enzyme for many dehydrogenases in Krebs cycle. Lipid & protein metabolism.
Deficiency states are rare, due to the presence in most of the foods we ear. Niacin deficiency causes Pellagra “translation: rough skin”. Primary symptoms involve the 3 D’s of Pellagra: Dermatitis, Diarrhea, Dementia
Health benefits conferred by Optimal Daily Allowance (ODA) : decreases cholesterol & triglycerides. Decreases risk of heart disease (?)
Adverse effects: flushing, GI upset, and may increase blood sugar levels. The “flushing” is similar to a hot flash, and is driven by prostaglandins. This flushing can be blocked by taking an Aspirin 325mg tablet one hour before the dose of niacin. Acetaminophen (Tylenol) does NOT work.
Supplemental doses: 50mg, 100mg, 250mg & 500 mg (immediate release release)
- No Flush niacin (inositol hexaniacinate) not as effective for hyperlipidemia
- At doses over 1 gram per day, Niacin will increase the chances of rhabdomyolisis, if a patient is currently taking a statin. Use only if benefits outweigh the risks
- OTC-Niacin: The immediate-release niacin formulations are more likely to cause flushing, especially first dose. Long-acting niacin Slo-Niacin (long acting niacin) is more likely to cause liver problems. Don’t recommend it for hyperlipidemia.
Let’s discuss prescription Niacin extended release:
- Niaspan® (Rx only) is an extended release prescription product that is used for hyperlipidemia, with minimal risk for liver dysfunction. Has fallen out of favor since September 2014. AIM-HIGH study: was stopped 18 months early because interim analysis showed lack of benefit of simvastatin/niacin vs simvastatin alone.
Niacin does NOT improve cardiovascular outcomes more than a statin alone when LDL is around 70 mg/dL. Adding niacin to bump up HDL makes number look better, but does not improve outcomes.
Patient Education for niacin therapy:
- Cutaneous flushing- may be managed with Aspirin 325mg 1 hour before dose.
- Take with food or light snack to decrease GI upset.
- Swallow whole, with cold water.
- Avoid sudden changes in posture. May cause dizziness.
- Avoid alcohol and hot drinks during administration.
- Increase blood glucose monitoring if diabetic.
- Watch niacin content in multivitamin.
SAFETY: For every 1000 patients treated for about 4 years with a statin plus niacin ( + aspirin), about 18 more will develop diabetes and 37 more diabetics will have worse glycemic control, compared to patients on a statin alone. Knowing that hyperlipidemia and diabetes go hand-in hand, this hardly seems a good trade-off.
RECOMMENDATION: Niacin is associated with stomach upset, diarrhea, rash, muscle pain, and flushing with possibly more infections and GI bleeding. If they have low LDL and stable cardiovascular disease recommend stopping the Niacin
The latest on Niacin: Oral Nicotinamide to Reduce Actinic Cancer (ONTRAC) study showed a form of vitamin B3 (niacinamide) showed a reduction in the risk of skin cancer of 23%. The though is that niacinamide may help repair sun-damaged skin and prevent immune suppression in the skin after sun exposure.
- Dose is 500mg BID if they have non-melanoma skin cancer. Reduces risk by 1 lesion per year. No proof of efficacy if patient does NOT have skin cancer.
- Keep recommending proper application of sunscreen and protective clothing.
By the way: No scientific evidence indicates that taking niacin can alter a urine drug test result. However, readily accessible information on the Internet lists ingestion of niacin as a way to prevent detection of tetrahydracannabinol (THC), the main psychoactive ingredient of marijuana. High dose niacin, may cause liver toxicity.
Have a great day on the bench!
Pete Kreckel———– Thompson Pharmacy Broad Avenue