The most frequent grade @-@ toxic effects were neutropenia ( @ -LSB- @ % -RSB- patients in placebo group vs @ -LSB- @ % -RSB- in metformin group ) , skin rash ( six -LSB- @ % -RSB- vs four -LSB- @ % -RSB- ) , diarrhoea ( three -LSB- @ % -RSB- vs six -LSB- @ % -RSB- ) , and fatigue ( two -LSB- @ % -RSB- vs six -LSB- @ % -RSB- ) .