Nicotinic acid/laropiprant reduces platelet count but increases mean platelet volume in patients with primary dyslipidemia

Introduction: Nicotinic acid (NA) has been associated with reduced cardiovascular morbidity and mortality. Of note, beyond its lipid-modifying actions, NA possesses a number of not yet thoroughly defined pleiotropic actions including anti-inflammatory and antithrombotic effects. As a growing body of evidence points towards mean platelet volume (MPV) and platelet distribution width (PDW) as independent risk factors for cardiovascular disease, it would be interesting to evaluate the effect of NA on these platelet indices. Material and methods: We recruited 50 consecutive patients with dyslipidemia who were treated with a conventional statin dose (10-40 mg simvastatin or 10-20 mg atorvastatin or 5-20 mg rosuvastatin) and had not achieved the low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) goal. Add-on-statin treatment with extended release (ER) NA/laropiprant (1,000/20 mg/day for the first 4 weeks followed by 2,000/40 mg/day for the next 8 weeks) was given to all patients for 3 months. Results: The ER-NA/laropiprant resulted in a 20% reduction in platelet count (from 277,150/mu l (min: 163,000/mu l - max: 223,400/mu l) to 220,480/mu l (min: 141,000/mu l - max: 319,000/mu l), p < 0.001), while it increased MPV by 3.5% (from 11.4 fl (min: 9.2 fl - max: 13.6 fl) to 11.8 fl (min: 9.5 fl - max: 14.1 fl), p = 0.01), without affecting PDW significantly (from 14.6 fl (min: 10.5 fl - max: 19.3 fl) to 14.5 fl (min: 11 fl - max: 21.1 fl), p = NS). Conclusions: The NA is associated with reduced platelet count but with increased MPV, thereby raising questions regarding NA's antithrombotic and vasculoprotective properties.