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ENDUR-ACIN® significantly improves blood cholesterol profiles in patient with dyslipidemia, study shows


  • Comparison of different ENDUR-ACIN® protocols (1,000-2,000 mg/day) over 20-week period
  • 1,500 mg/day protocol is most effective and best tolerated with 96% adherence.
  • Significant reductions in LDL cholesterol (-26%) and total-to-HDL cholesterol ratio (-20.4%) compared to diet-only or placebo reported
  • Low 3.4% dropout rate with ENDUR-ACIN® treatment


This double-blind, randomized, controlled trial involved 201 men and women, aged 20 to 70 years, with elevated LDL cholesterol values (in the 75th to 95th percentiles) and low- to moderate-risk for heart disease. Subjects were instructed to follow the American Heart Association Step I Diet for a minimum of 6 weeks prior to treatment and continue the diet plan for the duration of the study with unscheduled monitoring throughout the study to ensure compliance. Subjects were then randomly assigned to one of 7 treatment groups (see Table 1) for 20 weeks. Fasting lipid profiles were obtained in triplicate at the end of Phase 0 (diet only) and at the end of each treatment phase. Blood chemistry and side effects were monitored at study entry and at the end of Phase 2 and Phase 3. A total of 158 (79%) subjects completed the study.


Table 1.  Study Groups & Treatment Protocols
Treatment Protocol Phase 0


(6 wk)

Diet Only*

Phase 1


(4 wk)

Low Dose

Phase 2


(8 wk)

Intermediate Dose

Phase 3


(8 wk)

Full Dose

ENDUR-ACIN® 1,000 mg diet only 250 mg 500 mg 1000 mg
ENDUR-ACIN® 1,250 mg diet only 250 mg 750 mg 1250 mg
ENDUR-ACIN® 1,500 mg diet only 250 mg 1000 mg 1500 mg
ENDUR-ACIN® 2,000 mg diet only 250 mg 1500 mg 2000 mg
Placebo 1 diet only 1 tablet 2 tablet 4 tablet
Placebo 2** diet only 1 tablet 4 tablet 2 tablet
Diet Alone diet only diet only diet only diet only
*All groups began with a minimum of 6 weeks of diet only following the American Heart Association Step I Diet.


** The Placebo 2 protocol allowed for a scheduled reduction in total number of pills during final phase to assess medication compliance, dietary adherence and blood lipid values


Compared to diet-only and placebo, the high-dose ENDUR-ACIN® protocols (1,500 mg/day or 2,000 mg/day) resulted in significant (P<.05) improvements in blood lipids, including reductions in LDL cholesterol (-26% and -19.3%, respectively), total cholesterol (-18.4% and -13.3%, respectively), and total-to-HDL cholesterol ratio (-20.4% and -19.4%, respectively) by the end of Phase 3.

Compared to baseline, small increases in HDL cholesterol were reported after Phase 3 with the 1,200-, 1,500- and 2,000-mg protocols, but only reached significance with the 1,500-mg protocol. Blood triglyceride levels showed a modest, but not significant, improvement with the higher niacin protocols. Blood chemistry monitoring indicated that reduction in LDL cholesterol levels strongly correlated with an increase in baseline levels of some enzymes for niacin-treated subjects.

The dropout rate due to side effects was only 3.4%, primarily related to flushing, itching, tingling and digestive upset. This improved side-effect profile of the ENDUR-ACIN® wax-matrix form of nicotinic acid was particularly notable.

The authors note that, although niacin therapy must be individualized; these findings indicate that a 1,500-mg treatment protocol with ENDUR-ACIN® is effective and well tolerated by patients with dyslipidemia.


Keenan JM, Fontaine PL, Wenz JB, Myers S, Huang ZQ, Ripsin CM. Niacin revisited: a randomized, controlled trial of wax-matrix sustained-release niacin in hypercholesterolemia. Arch Intern Med. 1991;151(7):1424-32.

PMID: 2064495