Fig. 3From: Long-term study of the efficacy and safety of OnabotulinumtoxinA for the prevention of chronic migraine: COMPEL studyOral preventive treatments* currently or previously used by the enrolled population (N = 716). *Oral preventive treatments defined, for the purposes of this study, as any oral medication specifically prescribed for daily use for prevention of headache. NSAID = nonsteroidal anti-inflammatory drugBack to article page