NICOTINIC ACID (nIACIN) 



Another example of a pseudo-pellagrous state is the toxic psychosis 

 or exhaustion delirium sometimes seen after surgical operation or 

 delivery.^' Such cases have no previous history of deficiency disease, 

 but may have been maintained in hospital on a restricted diet for the 

 treatment of gastro-intestinal disease, or their metabolic demands may 

 have been increased by fever. In these cases, the onset of delirium 

 hallucinations or mania is frequently abrupt, but physical signs are 

 absent. In rare instances there may be acute stomatitis and glossitis 

 with an abundance of Vincent's organisms. Response to nicotinic 

 acid or nicotinamide is rapid. 



Another condition, due at least in part to nicotinic acid deficiency, 

 is Wernicke's syndrome,^^ characterised by clouding of the conscious- 

 ness, cogwheel rigidities and uncontrollable grasping and sucking 

 reflexes ; many such patients have involvement of the mid-brain 

 and some peripheral neuropathy. About half of the patients exam- 

 ined had clinical evidence of pellagra, and all were alcoholic. The 

 mortality rate was very high, but fell considerably when nicotinic 

 acid treatment was introduced. This condition is believed to repre- 

 sent the extreme picture of nicotinic acid deficiency. 



Another form of vitamin B deficiency results when diabetics are 

 maintained on a high carbohydrate diet with insulin injections. In 

 this instance, energy is derived from carbohydrate in excess of the 

 vitamin reserves, which are gradually depleted and not replaced. 

 Such cases respond well to nicotinic acid and riboflavine. Another 

 type of case where similar treatment is successful is the elderly or 

 senile stuporous condition generally given glucose to combat dehydra- 

 tion ; 3® nicotinic acid treatment reduced the mortality rate dramatic- 

 ally in such cases. It has been suggested that this result may be due 

 in part to the vasodilator effect of nicotinic acid increasing the supply 

 of blood to the brain (see page 274) ; nicotinamide and nikethamide, 

 however, which have no vasodilator effect, produce cures in cases of 

 stupor and encephalopathy as rapidly as does nicotinic acid. 



Other factors that may precipitate symptoms of nicotinic acid 

 deficiency are hard manual work and infection, both of which lead to 

 a heightened metabolism and therefore to an increased consumption 

 of coenzymes I and II ; snake venom, which is known to inactivate 

 coenzyme I ; and cyanogenetic glycosides, which may also inactivate 

 coenzyme I by the liberation of hydrogen cyanide. 



Other Conditions affected by Nicotinic Acid 



Other conditions besides pellagra and " pseudo pellagra " may 

 benefit by nicotinic acid treatment. Thus, J. D. King ^^ found that 

 nicotinic acid cured Vincent's angina, an ulcerative infection of the 



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