Patients' experiences of niacin-induced flushing in clinical practice: a structured telephone interview

Niacin is highly effective at raising high-density lipoprotein cholesterol but remains underused because of the adverse event of flushing.

The objective of this study was to determine the incidence and severity of niacin-induced flushing and their relationship to niacin discontinuation and skipping or delaying niacin doses in clinical practice. The use of aspirin to avoid niacin-induced flushing was also assessed.

Structured telephone interviews were performed with patients identified from administrative claims data as having newly initiated niacin. The main outcome measures were rate and severity of flushing, association between flushing and niacin discontinuation, and rate of prophylactic aspirin use to avoid flushing. Flushing was evaluated on a scale of none, mild, moderate, severe, and extreme.

Telephone interviews were conducted with 500 patients who had newly initiated niacin. The patients interviewed were predominantly white men with at least some college education and a mean (SD) age of 55.0 (10.9) years. The mean (SD) time between therapy initiation and interview was 9.3 (3.3) months. At the time of the interview, 27.2% of respondents reported having discontinued niacin ("discontinuers"; n = 136), with a mean duration of niacin use of 4.3 months, and 72.8% continued taking niacin ("continuers"; n = 364). Approximately 91.2% (124/136) of niacin discontinuers and 82.1% (299/364) of continues reported experiencing flushing symptoms (P = 0.013), and 54.4% of discontinuers versus 20.9% of continuers experienced severe or extreme flushing (P < 0.001). Significantly more discontinuers (79.4%) than continuers (58.0%) reported that the greatest degree of flushing they could tolerate was "mild" or "moderate" (P < 0.001). Multivariate logistic regression indicated that flushing symptom severity was a strong predictor of discontinuation as compared with no flushing symptoms (severe: odds ratio [OR], 3.19; 95% CI, 1.43-7.15; extreme: OR, 11.29; 95% CI, 4.20-30.39). Similar percentages of discontinuers and continuers reported both receiving a physician's advice to take prophylactic aspirin (42.0% vs 49.5%, respectively; P = NS) and actually taking aspirin regardless of what their physicians advised (36.0% vs 43.7%; P = NS).

Severe or extreme symptoms of flushing, which occurred in about one third of patients newly treated with niacin, were associated with discontinuation of this otherwise highly effective therapy. Less than half of patients reported being advised by their physician to take prophylactic aspirin or took aspirin regardless of their physician's recommendation to avoid niacin-induced flushing symptoms.