Two Cochrane reviews were One considered the effectiveness of metformin monotherapy compared with placebo or any active The other review included studies of metformin alone or in combination with other treatments compared with placebo or a range of other treatments, with the aim of reporting deaths due to lactic acidosis and non-fatal cases of lactic Similarly, an RCT was identified which compared serious adverse events (AEs) and plasma lactate levels between metformin and non-metformin treated groups
