Hypotension, nicotinic acid

Nicotinic acid and its derivatives (pyridylcarbinol, xanthinol nicotinate, acipimox) activate endothelial lipoprotein lipase and thereby lower triglyceride levels. At the start of therapy, a prostaglandin-mediated vasodilation occurs (flushing and hypotension) that can be prevented by low doses of acetyl-salicylic acid. 

Nicotinic acid (5.18), and related derivatives such as pyridylcarbinol (5.19), xanthinol nicotinate (5.20), acipimox (5.21), given in large doses, influence the lipoprotein ratio, decreasing the concentrations of very low and low-density lipoprotein, but have no effect on HDL-cholesterol complexes. Acipimox (5.21) is a new pyrazine derivative that is 20 times more active than nicotinic acid. When first administered, the use of these agents is associated with flushing and hypotension. 

A 50-year-old man developed recurrent sharp lower abdominal pain and nausea, having taken modified-release nicotinic acid 500-2000 mg/day for 8 weeks for hypercholesterolemia. He had a low-grade fever, tachycardia, and hypotension. Abdominal ultrasonography showed a markedly hypoechoic liver of normal size,... 

Nicotinic acid (hut not nicotinamide) causes a marked vasodilatation, with flushing, burning, and itching of the skin. Very large single doses of nicotinic acid may cause sufficient vasodilatation to lead to hypotension after the administration of 1 to 3 g of nicotinic acid daily for several days, the effect wears off to a considerable extent. A number of nicotinoyl esters have been developed to permit sensitive patients to benefit from the hypoUpidemic effect of... 

Contraindications Thiamine patients with renal dysfunction Riboflavin patients with renal dysfunction Niacin or nicotinic acid hypersensitivity to niacin or tartrazine active peptic ulcer, severe hypotension, hepatic dysfunction, arterial hemorrhaging Caution diabetes mellitus, gallbladder disease, gout, history of jaundice or Uver disease. Pyridoxine IV therapy in cardiac patients Caution megadosage in pregnancy... 

Excessive nicotinic acid can cause transient vasodilation with hypotension... 

XXXIII, are active in DOCA rats and in dogs. The nicotinic acid ester H-1 (XXXIV) is a hypotensive and vasodilator in spontaneous hypertensive rats. ... 

Analogs of nicotine and anabasine in which the pyridine ring has been replaced by quinuclidine (XXI a and both diastereoisomers of XX lb) show hypotensive effects when given i.v. to dogs. The hydrazide of yohimboic acid, which is considerably less toxic than the methyl ester (yohimbine), causes prolonged hypotension at I mg/kg (i.v.) in chioralosed dogs. ... 

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