Editing Niacin (section)

===Pharmacodynamics===
Activating HCA<sub>2</sub> has effects other than lowering serum cholesterol and triglyceride concentrations: antioxidative, anti-inflammatory, antithrombotic, improved [[endothelium|endothelial]] function and [[atheroma|plaque]] stability, all of which counter development and progression of atherosclerosis.<ref name=Zeman2015>{{cite journal |vauthors=Zeman M, Vecka M, Perlík F, Hromádka R, Staňková B, Tvrzická E, Žák A |title=Niacin in the Treatment of Hyperlipidemias in Light of New Clinical Trials: Has Niacin Lost its Place? |journal=Med. Sci. Monit. |volume=21 |pages=2156–62 |date=July 2015 |pmid=26210594 |pmc=4523006 |doi=10.12659/MSM.893619 }}</ref><ref>{{cite journal | vauthors = Wu BJ, Yan L, Charlton F, Witting P, Barter PJ, Rye KA | title = Evidence that niacin inhibits acute vascular inflammation and improves endothelial dysfunction independent of changes in plasma lipids | journal = Arteriosclerosis, Thrombosis, and Vascular Biology | volume = 30 | issue = 5 | pages = 968–75 | date = May 2010 | pmid = 20167660 | doi = 10.1161/ATVBAHA.109.201129 | doi-access = free }}</ref>

Niacin [[Enzyme inhibitor|inhibits]] [[cytochrome P450]] enzymes [[CYP2E1]], [[CYP2D6]] and [[CYP3A4]].<ref name = "Gaudineau_2004">{{cite journal | vauthors = Gaudineau C, Auclair K | title = Inhibition of human P450 enzymes by nicotinic acid and nicotinamide | journal = Biochemical and Biophysical Research Communications | volume = 317 | issue = 3 | pages = 950–6 | date = May 2004 | pmid = 15081432 | doi = 10.1016/j.bbrc.2004.03.137 }}</ref> Niacin produces a rise in serum [[Bilirubin#Indirect (unconjugated)|unconjugated bilirubin]] in normal individuals and in those with [[Gilbert's Syndrome]]. However, in the Gilbert's Syndrome, the rise in bilirubin is higher and clearance is delayed longer than in normal people.<ref>{{cite book |title=Nathan and Oski's Hematology of Infancy and Childhood |pages=118–119 |isbn=9781416034308| vauthors = Orkin SH, Nathan DG |date=January 2009 |publisher=Elsevier Health Sciences }}</ref> One test used to aid in diagnosing Gilbert's Syndrome involves intravenous administration of nicotinic acid (niacin) in a dose of 50&nbsp;mg over a period of 30 seconds.<ref name="bil1">{{cite journal | vauthors = Dickey W, McAleer JJ, Callender ME | title = The Nicotinic Acid Provocation Test and Unconjugated Hyperbilirubinaemia | journal = The Ulster Medical Journal | volume = 60 | issue = 1 | pages = 49–52 | date = April 1991 | pmid = 1853497 | pmc = 2448612 }}</ref><ref name="bil2">{{cite journal | vauthors = Röllinghoff W, Paumgartner G, Preisig R | title = Nicotinic Acid Test in the Diagnosis of Gilbert's Syndrome: Correlation With Bilirubin Clearance | journal = Gut | volume = 22 | issue = 8 | pages = 663–668 | date = August 1981 | pmid = 7286783 | pmc = 1420060 | doi = 10.1136/gut.22.8.663 }}</ref>
{{See also|Niacin#Liver_damage}}