Pharmacological Uses of Niacin

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). 

In experimental animals, nicotinamide protects against the destruction of pancreatic /S-islet cells caused by diabetogenic agents, such as alloxan and 

Gram doses of nicotinamide have been used in so-called orthomolecular psychiatry as a treatment for schizophrenia, originally because of the similarities between schizophrema and the depressive psychosis of pellagra. The underlying rationale for this use is that such high doses of niacin may deplete methyl donors, and at least one of the theories of the biochemical basis of schizophrenia was that the condition is caused by inappropriate methylation of neurotransmitter metabolites to yield psychotogenic compounds (Hoffer et al., 1957). There is no independent confirmation of the efficacy of nicotinamide in the treatment of schizophrenia. 

Bender DA (1983) Biochemistry of tryptophan in heaith and disease. Molecular Aspects of Medicines, 101-97. 

Bender DA (1996) Tryptophan and niacin nutrition - is there a prohXemI Advances in Experimental Medicine and Biology 398, 565-9. 

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Prousky, J., Millman, C., and Kirkland, J., 2011. Pharmacologic use of niacin. Journal of Evidence-Based Complementary Alternative Medicine. 16 91-101. 

Biochemistry of NAD NAD Used for Nonredox Purpose History of Niacin Nutrition Ass sment of Niacin Static Pharmacological Use of Nicotinic Add Thiamin... 

Adverse effects of niacin are most commonly seen when this vitamin is used at pharmacological doses above I g/day in the treatment of dyslipidemia. Notable adverse effects include flushing due to vasodilatation dermatological effects including dry skin pruritus and hyperkeratosis gastrointestinal effects including peptic ulcer,. stomach pain, nausea. and diarrhea elevations in serum uric acid and glucose and hepatotoxicity. ... 

We regard as unfortunate the strict traditional use of nicotinic acid for the lipid-modifying pharmacological agent and niacin for the vitamin including... 

A recent study showed abnormal niacin sensitivity in schizophrenia patients as evidenced by attenuation of the flush response to niacin in schizophrenia. However, there is still an ongoing debate whether this response is due to altered pharmacological sensitivity to niacin or an inadequate cutaneous vasodilatory response to the stimulus (Messamore et al. 2003). Early studies even attempted to use niacin as an augmenting agent for the treatment of schizophrenia with mixed results (Ananth et al. 1973 Petrie et al. 1981). In a placebo-controlled comparative study by Ramsay et al. (1970), it was found that, while no significant differences were seen in total Brief Psychiatric Rating Scale (BPRS) scores prior to commencement of the clinical trial, statistically significant... 

All HMGRIs are approved for the treatment of primary hypercholesterolemia and familial combined hyperlipidemia (Fredrickson s type Ha and lib) (Table 30.2) In patients who have not responded to diet, exercise, and other non pharmacological methods (Table 30.6) (15,21). They may be used either alone or In combination with bile acid sequestrants, ezetimibe, or niacin. As previously mentioned, they should be administered at least 1 hour before or 4 to 6 hours after bile acid sequestrants when this combination Is desired. Fluvastatin, lovastatin, pravastatin, and simvastatin have been specifically Indicated to reduce the mortality of CHD and stroke. By reducing plasma LDL levels, these compounds slow the progression of atherosclerosis and reduce the risk of myocardial Infarction and other ramifications of vascular occlusion. Atorvastatin, rosuvastatin, and simvastatin have been shown to be effective In homozygous familial hyperlipidemia and are Indicated for this use. Additionally, atorvastatin, pravastatin, and simvastatin are Indicated for primary dysbetallpoprotelnemla (Fredrickson s type III) (Table 30.2). Finally, atorvastatin, pravastatin, rosuvastatin, and simvastatin are Indicated for the treatment of hypertriglyceridemia. 

Fibrates are approved to treat hypertriglyceridemia and familial combined hyperlipidemia (Fredrickson s type lla, lib, IV, and V) (Table 30.2) in patients who are at risk of pancreatitis and have not responded to dietary adjustments or in patients who are at risk of CHD and have not responded to weight loss, dietary adjustments, and other pharmacological treatment. They can be used either alone or in combination with niacin, bile acid sequestrants, or FlMGRIs. If used with bile acid sequestrants, fibrates must be taken either 1 hour before or 4 to 6 hours after the sequestrant. As discussed previously and reemphasized below, caution should be used it fibrates are combined with HMGRIs. Fibrates are not effective in the treatment of hypertriglyceridemia associated solely to elevated chylomicron levels (Fredrickson s type I). 

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