niacin

Research Excerpts

Overview

Niacin (NIA) is a water-soluble vitamin and the primary treatment of pellagra. Niacin serves as a high-affinity ligand for the receptor HCAR2 (GPR109A)

Effects

Niacin has a variety of uses, particularly in treating various skin conditions, including topically as an anti-acne treatment. It promotes epidermal sphingolipid synthesis, moderating photoimmunosuppression, and reducing hyperpigmentation. Niacin also has a small, direct effect on platelet aggregation.

Niacin has been used for decades to treat dyslipidaemic disorders. Niacin and fibrates have been shown in clinical trials to be effective as adjunctive therapy for these lipid abnormalities.

Actions

Niacin is known to cause rapidly progressive, widespread AN that is reversible upon discontinuation of the medication. Niacin may also increase glucose levels, liver enzymes, and uric acid levels and cause other AEs that may have clinical relevance in selected patients.

Treatment

ER-niacin's role in the treatment of antiretroviral therapy-associated dyslipidemia requires further evaluation, but the results of this pilot study indicate that it is safe and tolerated. Niacin treatment for 2 or 4 weeks lowered serum cholesterol concentrations by 13% or 29%.

Toxicity

Niacin has favorable effects on serum lipoprotein regulation and on containment of atherothrombotic cardiovascular diseases. Current drug labeling warns of an increased risk of adverse events with statin and niacin combinations.

Pharmacokinetics

There is a small pharmacokinetic drug interaction between ER niacin and ezetimibe/simvastatin. Although this is not considered to be clinically significant, the concomitant use of these drugs should be appropriately monitored.

Compound-Compound Interactions

Fluvastatin, a new synthetic inhibitor of HMGCoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase, has been studied in several models to examine its effects when used in combination with other lipid-modifying agents such as deri. These results demonstrate that laropiprant does not enhance in vivo platelet reactivity, either alone or in combinations with niacin.

Bioavailability

The intestinal bioavailability of niacin and pantothenic acid was affected differently by the food administered. Dried skim milk with most of its niakin in free form showed 98% niacins equivalent to be bioavailable. In pearl millet niacIn was in bound form and bioavailability equivalent was only 48 per cent.

Dosage Studied

The favorable safety and tolerability profile of ERN/LRPT for up to 1 year supports the use of LRPT to achieve improved therapeutic dosing of niacin. Niacin is an agent with comprehensive lipid-modifying efficacy and shown to reduce cardiovascular risk.