Nicotinic Acid: An Unjustly Neglected Remedy

Overview

In human organism, the administration of nicotinic acid (niacin) leads to two types of effects. Within the physiological range (≈20 mg/day), niacin has a vitamin-like role as pellagra preventing factor. The pharmacological dosage (≈0,5-4,5 g/day) substantially influences the plasma lipid and lipoprotein concentrations: decreases VLDL and LDL concentrations, changes the profile of LDL subfractions towards the larger particles as well as particles with lower density; it also profoundly increases the concentration of HDL-C in consequence of elevated concentration of HDL2 subfraction. Niacin as the only hypolipidemic drug reduces the lipoprotein(a) concentration. The hypolipidemic mechanism of niacin is different from that of other hypolipidemic drugs. On the basis of clinically controlled trials (both interventional epidemiological and angiographical), which satisfy the criteria of evidence-based medicine, it is possible to conclude that niacin falls unambiguously into the class of hypolipidemic drugs with proven beneficial effect not only on cardiovascular mortality and morbidity, but also on total mortality. Therefore, niacin should have an indisputable role in the pharmacological control of dyslipidemias. With the respect of basic mechanism (inhibition of the lipolysis of adipose tissue) with subsequent decrease in the concentration of free fatty acids and their flux to liver, niacin fulfils the criteria for pathogenetic treatment of atherogenic dyslipidemia in metabolic syndrome. The prerequisite condition for the niacin treatment is the respect for serious adverse effects and possible health hazards of administration (skin flush, hepatotoxicity and deterioration of glucose homeostasis). Recently discovered extrahypolipidemic effects of niacin (antioxidative activity, facilitation of reverse cholesterol transport, activation of PPAR-γ, antithrombotic effects) and the introduction of drug forms with sustained (extended resp.) release of active compound (that minimizes the adverse effects and administration hazards) form together the basis for firm statement that the derivatives of nicotinic acid should be introduced to the clinical practice in Czech Republic. 

Key words:
niacin, flush, deterioration of glucose homeostasis, hepatotoxicity, inhibition of lipolysis, hypolipidemic effects, changes in cardiovascular morbidity and mortality, sustained (extended resp.) release.