Hyperlipidemia niacin

Acipimox (5) was introduced in Europe to treat hyperlipidemia in 1985 [47,48]. Acipimox is a weak agonist of GPR109A with micromolar binding and functional activity. Like niacin, acipimox raises HDL-C and triggers vasodilation in humans. However, it remains unclear whether acipimox causes mild hyperglycemia as is observed with niacin [49,50]. 

The principal use of niacin is for mixed hyperlipidemia or as a second-line agent in combination therapy for hypercholesterolemia. It is a first-line agent or alternative for the treatment of hypertriglyceridemia and diabetic dyslipidemia. 

Primary hypercholesterolemia (familial hypercholesterolemia, familial combined hyperlipidemia, type Ila hyperlipoproteinemia) is treated with BARs, statins, niacin, or ezetimibe. 

Niacin has been used clinically to lower serum cholesterol levels (see Chapter 23). It is used as adjunctive therapy in patients with hyperlipidemia. It is one of the drugs of first choice for patients who do not respond adequately to diet and weight loss. 

Sites of action of HMG-CoA reductase inhibitors, niacin, ezetimibe, and resins used in treating hyperlipidemias. Low-density lipoprotein (LDL) receptors are increased by treatment with resins and HMG-CoA reductase inhibitors. VLDL, very-low-density lipoproteins R, LDL receptor. 

Reductase inhibitors are useful alone or with resins, niacin, or ezetimibe in reducing levels of LDL. Women with hyperlipidemia who are pregnant, lactating, or likely to become pregnant should not be given these agents. Use in children is restricted to selected patients with familial hypercholesterolemia or familial combined hyperlipidemia. 

In combination with a resin or reductase inhibitor, niacin normalizes LDL in most patients with heterozygous familial hypercholesterolemia and other forms of hypercholesterolemia. These combinations are also indicated in some cases of nephrosis. In severe mixed lipemia that is incompletely responsive to diet, niacin often produces marked reduction of triglycerides, an effect enhanced by marine omega-3 fatty acids. It is useful in patients with combined hyperlipidemia and in those with dysbetalipoproteinemia. It is clearly the most effective agent for increasing HDL and the only agent that may reduce Lp(a). 

This combination is sometimes useful in treating patients with familial combined hyperlipidemia who are intolerant of niacin or statins. However, it may increase the risk of cholelithiasis. 

Pellagra Dermatitis Diarrhea Dementia None High doses of niacin used to treat hyperlipidemia... 

Niacin (nicotinic acid, nicotinamide) has the active forms NAD and NADPH. It functions in electron transfer. A deficiency of niacin causes pellagra, which is characterized by der matitis, diarrhea, and dementia. There is no known toxicity for this vitamin. High doses of niacin are used to treat hyperlipidemia. 

Goldberg A, Alagona DP Jr, Capuzzi DM, Guyton J, Morgan JM, Rodgers J, Sachson R, Samuel P. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol 2000 85 1100-5. 

Therapeutic uses The bile acid binding resins are the drugs of choice (often in combination with diet or niacin) in treating Type lla and lib hyperlipidemias. [Note In those rare individuals who are homozygous for Type lla, that is, for whom functional LDL receptors are totally lacking, these drugs have little effect on plasma LDL levels.] Cholestyramine can also relieve pruritus caused by accumulation of bile acids in patients with biliary obstruction. 

The European Health Food Manufacturers Federation restricts over-the-counter supplements to 500 mg per day (Shrimpton, 1997). Where niacin is being used to treat clinically significant hyperlipidemia, and in trials for the prevention of type I diabetes mellitus, a tentative upper limit has been set at 3 g per day (Knip et al., 2000). 

Niacin (but not niacinamide) is also indicated in hyperlipidemia to lower uiglycerides and cholesterol. Triglycerides. VLDL.S, and LDLs are reduced HDLs are increased. The exact mechanism is not known. Because niacin at high doses has a direct vasodilatory effect believed to be mediated through the prostaglandins, the dose required (1 to 3 g 3 times daily) often limits the usefiilne.ss. 

B3 (niacin) Treats pellagra (dietary deficiency of niacin) and hyperlipidemia. Can cause GI irritation and vasodilatation results in a flushing sensation... 

Dose for deficiency Thiamine 30-60 mg/d Riboflavin 5-25 mg/d Prophylactic 3 mg/d Nicotinic acid or niacin Prevention 5-20 mg/d Deficit 50-100 mg/d Pellagra 300-500 mg in three divided doses Hyperlipidemia 1-2 g/d in three divided doses Pyridoxine 25-100 mg/d Isoniazid therapy prophylaxis 25-20 mg/d Peripheral neuritis 50-200 mg/d... 

Guyton JR, Capuzzi DM (1998) Treatment of hyperlipidemia with combined niacin-statin regimens. Am J... 

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