Correlation between lipophilicity and triptan outcomes

BACKGROUND: It has been suggested that triptans achieving higher central nervous system (CNS) levels should have an advantage in efficacy, if central actions are important. Objective.-Our aim was to correlate the efficacy and tolerability results of triptans with their lipophilicity. METHODS: Data for response and pain free at 2 hours, recurrence, adverse events (AE), CNS AE, and chest symptoms taken from Ferrari et al's meta-analysis publications for the recommended doses of oral triptans were correlated with their lipophilicity coefficients (logD(pH)7.4 = -2.1 almotriptan < -1.5 sumatriptan < -1.0 zolmitriptan < -0.7 rizatriptan < -0.2 naratriptan < 0.5 eletriptan). RESULTS: We found no significant correlation between lipophilicity coefficients and any of the analyzed parameters. There was, however, some correlation between lipophilicity and CNS AE (P = .09, r = 0.74) and, to a lesser degree, with a reduction in recurrence rate (r = -0.36). The r values for response and pain free with placebo correction ranged from 0.04 to 0.34, suggesting almost no correlation between lipophilicity and efficacy variables. CONCLUSIONS: According to this analysis, a higher lipophilicity does not seem crucial to improve triptan efficacy. This physico-chemical property, however, correlates with higher CNS AE and, possibly, lower recurrence rates.