AAC was significantly superior to IB for pain relief at 45 minutes and at one , two , three , and four hours postdose ( p < 0.04 ) ; pain intensity difference from one hour through three hours ( p < 0.05 ) ; headache response at two hours ( p = 0.04 ) ; functional disability reduced to little or none at three hours ( p = 0.013 ) ; freedom from phonophobia at three hours ( p = 0.04 ) and photophobia at 15 minutes postdose ( p = 0.03 ) ; and use of rescue medication ( p = 0.018 ) .