NICOTINIC ACID AND NICOTINAMIDE ARE USED IN THE TREATMENT AND PREVENTION OF NICOTINIC ACID DEFICIENCY. NICOTINAMIDE IS PREFERRED AS IT DOES NOT CAUSE VASODILATATION. THEY ARE USUALLY GIVEN BY MOUTH, THE PREFERRED ROUTE, BUT MAY ALSO BE GIVEN BY THE INTRAMUSCULAR ROUTE OR BY SLOW INTRAVENOUS INJECTION. DOSES OF UP TO 500 MG DAILY (OF EITHER COMPOUND) IN DIVIDED DOSES HAVE BEEN RECOMMENDED.
NICOTINIC ACID HAS BEEN USED FOR ITS VASODILATOR ACTION IN THE TREATMENT OF A VARIETY OF DISORDERS; ITS VALUE IS NOT CONSIDERED TO BE ESTABLISHED.
IN HIGH DOSES, NICOTINIC ACID HAS BENEFICIAL EFFECTS ON BLOOD LIPID PROFILES, AND HAS BEEN USED, WITH DIETARY MODIFICATION AND OFTEN WITH OTHER LIPID REGULATING DRUGS, IN HYPERLIPIDAEMIAS . FOR THE IMMEDIATE-RELEASE PREPARATIONS, UP TO 600 MG DAILY BY MOUTH IN 3 DIVIDED DOSES HAS BEEN GIVEN INITIALLY, GRADUALLY INCREASED OVER 2 TO 4 WEEKS TO DOSES OF UP TO 6 G DAILY; ADVERSE EFFECTS MAY BE A LIMITING FACTOR. ALTERNATIVELY, INITIAL DOSES OF 375 OR 500 MG AT NIGHT HAVE BEEN GIVEN AS A MODIFIED-RELEASE PREPARATION AND GRADUALLY INCREASED ACCORDING TO RESPONSE TO A MAINTENANCE DOSE OF 1 TO 2 G AT BEDTIME. THE DAILY DOSE SHOULD NOT BE INCREASED BY MORE THAN 500 MG IN ANY 4-WEEK PERIOD.
TOPICAL NICOTINAMIDE IS USED IN THE TREATMENT OF MILD TO MODERATE INFLAMMATORY ACNE TYPICALLY AS A 4% GEL APPLIED TWICE DAILY.
NICOTINAMIDE HAS BEEN SHOWN TO INHIBIT THE DESTRUCTION OF PANCREATIC BETA CELLS IN VITRO AND IS THEREFORE BEING INVESTIGATED IN THE PREVENTION AND TREATMENT OF TYPE 1 DIABETES MELLITUS .
ACNE.
TOPICAL NICOTINAMIDE MAY BE USED IN THE TREATMENT OF INFLAMMATORY ACNE; NICOTINAMIDE 4% WAS AS EFFECTIVE AS CLINDAMYCIN 1% WHEN APPLIED TOPICALLY TWICE DAILY FOR 8 WEEKS.
DIABETES MELLITUS.
NICOTINIC ACID CAN AFFECT GLUCOSE TOLERANCE AND SHOULD BE USED WITH CARE IN ESTABLISHED DIABETES (SEE UNDER ADVERSE EFFECTS AND TREATMENT). HOWEVER, THE DRUG HAS BEEN USED SUCCESSFULLY IN PATIENTS WITH DIABETES. NICOTINAMIDE HAS BEEN REPORTED TO INDUCE REMISSION IN PATIENTS WITH NEWLY DIAGNOSED TYPE 1 DIABETES MELLITUS, AND MAY DELAY THE ONSET OF DISEASE. HOWEVER, A RANDOMISED TRIAL FOUND MODIFIED-RELEASE NICOTINAMIDE AT 1.2 G/M2 DAILY (TO A MAXIMUM OF 3 G DAILY) TO BE INEFFECTIVE IN PREVENTING THE ONSET OF DIABETES MELLITUS IN FIRST-DEGREE RELATIVES OF PATIENTS WITH THE DISEASE. NICOTINIC ACID CAN ALSO RAISE HIGH-DENSITY LIPOPROTEIN (HDL)-CHOLESTEROL CONCENTRATIONS , CHANGES IN GLUCOSE TOLERANCE WERE MILD ENOUGH FOR THE DRUG TO BE CONSIDERED AS AN ALTERNATIVE TO STATINS AND FIBRATES IN DIABETIC PATIENTS.
HYPERLIPIDAEMIAS.
THE FIRST-LINE TREATMENT FOR HYPERLIPIDAEMIAS REMAINS DIETARY AND LIFESTYLE MODIFICATION; WHERE THIS FAILS, DRUG THERAPY MAY BE CONSIDERED . NICOTINIC ACID IS REPORTED TO HAVE A FAVOURABLE EFFECT ON BLOOD-LIPID PROFILES, RAISING HIGH-DENSITY LIPOPROTEIN (HDL)-CHOLESTEROL AND LOWERING LOW-DENSITY LIPOPROTEIN (LDL)-CHOLESTEROL. NICOTINIC ACID IS USED PARTICULARLY IN FAMILIAL HYPERTRIGLYCERIDAEMIA, OR IN FAMILIAL COMBINED HYPERLIPIDAEMIA WHEN BOTH TRIGLYCERIDE AND CHOLESTEROL CONCENTRATIONS ARE SIMILARLY ELEVATED. NICOTINIC ACID WAS LESS EFFECTIVE THAN LOVASTATIN AT REDUCING LDL-CHOLESTEROL IN PATIENTS WITH PRIMARY HYPERCHOLESTEROLAEMIA, BUT MORE EFFECTIVE AT INCREASING HDL-CHOLESTEROL; LOVASTATIN WAS BETTER TOLERATED. A COMBINATION OF NICOTINIC ACID WITH LOVASTATIN WAS FOUND TO BE COMPARABLE TO ATORVASTATIN AND MORE EFFECTIVE THAN SIMVASTATIN IN REDUCING LDL-CHOLESTEROL, AND MORE EFFECTIVE THAN EITHER ATORVASTATIN OR SIMVASTATIN IN INCREASING HDL-CHOLESTEROL, IN A STUDY OF PATIENTS WITH DYSLIPIDAEMIA. SOME HAVE RECOMMENDED THAT NICOTINIC ACID BE SUBSTITUTED FOR A STATIN TO LOWER LDL-CHOLESTEROL WHEN PATIENTS CANNOT TOLERATE A STATIN. COMBINATION THERAPY IS RECOMMENDED WHEN THE REDUCTION IN LDL-CHOLESTEROL IS INSUFFICIENT WITH STATIN MONOTHERAPY, OR WHEN RAISING HDL-CHOLESTEROL WOULD BE BENEFICIAL, AS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS, OR THE METABOLIC SYNDROME. THE RISK OF MUSCLE TOXICITY WITH THIS COMBINATION IS NOT CONSIDERED TO BE SIGNIFICANTLY DIFFERENT TO THAT WITH STATIN MONOTHERAPY.
PEMPHIGUS.
ORAL TREATMENT WITH NICOTINAMIDE AND A TETRACYCLINE HAS CONTROLLED LESIONS IN PEMPHIGUS AND PEMPHIGOID, INCLUDING PERSISTENT PEMPHIGOID GESTATIONIS, AND OCULAR CICATRICIAL PEMPHIGOID.