Aim. Naratriptan is a new member of the triptans which are used in aborting attacks of migraine. But triptans may cause chest pain, myocardial infarction and arrhythmias in some patients. Naratriptan shows antimigraine effect by activating 5HT1B/1D receptors. The activation of 5HT1B/1D receptors also reduces the secretion of noradrenaline from cardiac sympathetic nerves. The effect of naratriptan on cardiac autonomic function is not known. The aim of this study is to find out, if any the effect of naratriptan on cardiac autonomic function by evaluating time and frequency domain parameters of heart rate variability. Methods. Nine patients with migraine (8 women, mean age: 37±4 years) were included in a pilot, double blinded, crossover and randomized study. All participants took 2.5 mg naratriptan or placebo at least 5 days apart. Both time domain and frequency domain heart rate variability (HRV) parameters were obtained during rest, controlled respiration and handgrip exercise, before and 2 hours later naratriptan or placeboadministration. Results. BaselineHRVparameters were similar before administration of naratriptan or placebo. Time domain parameters [and mean RR interval, the standard deviation of R-R interval (SDNN) and the root mean square of successive R-R interval differences (RMSSD)] and frequency domain parameters [low frequency (LF) and high frequency (HF) spectral powers and LF/HF ratio] obtained after naratriptan administration were not different when compared with placebo. Conclusions. A single dose 2.5 mg oral naratriptan administration did not change sympathetic, parasympathetic reactivity and sympathovagal balance in migraneurs.

        Key words: migraine, naratriptan, heart rate variability, cardiac autonomic functions