Adverse events were similar between the three groups , the most common being headache reported by 24 ( 11 % ) of 212 patients enrolled in placebo group , 12 ( 6 % ) of 201 patients in the low-dose group , and 17 ( 8 % ) of 211 patients in the high-dose group , or diarrhoea , reported by seven ( 3 % ) patients in the placebo group , four ( 2 % ) patients enrolled in the low-dose group , and 17 ( 8 % ) patients in the high-dose group .