Nicotinamide: An Update and Review of Safety & Differences From Niacin

Reed Huber, BSc; Aaron Wong, MD, FRCPC

Disclosures

Skin Therapy Letter. 2020;25(5):7-11. 

In This Article

Nicotinamide and how it Relates to Niacin

Nicotinamide is the amide version of its carboxylic acid precursor niacin (or nicotinic acid). Historically, niacin was identified as the first lipid-modifying drug when hypercholesteremia was beginning to be recognized as a risk factor for cardiovascular disease around the middle of the 20th century.[1] However, the use of niacin in the treatment of dyslipidemia was limited due to common cutaneous adverse effects, mainly flushing and telangiectasias.[2] Biochemically, nicotinamide and niacin are sequential precursors in the pathway converting the essential amino acid tryptophan into the ubiquitous electron acceptor cofactor nicotinamide adenine dinucleotide (NAD+) (Figure 1). Despite their structural and chemical similarity, nicotinamide and niacin differ significantly from a therapeutic standpoint, in that nicotinamide does not share either of the aforementioned lipid-modifying and vasodilatory effects of niacin.[3] This dissimilarity is best explained by the release of prostaglandin D2 from the skin via an unknown mechanism causing cutaneous vasodilation and through specific nicotinic acid receptor binding interactions in adipose tissue[3,4] An overview of the differences between nicotinamide and niacin are summarized in Table 1.

Figure 1.

Metabolism of tryptophan to NAD+ and NADP.
NAD+ = nicotinamide adenine dinucleotide
NADP = nicotinamide adenine dinucleotide phosphate

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