After being informed about the study and potential risks, all patients giving written informed consent will undergo a 1 day screening period to determine eligibility for study entry. At day 0, patients who meet the eligibility requirements will be randomized in a double blind manner (participant and investigator) in a 1:1 ratio to metformin glycinate (620 mg, taken orally, twice daily) plus standard treatment or placebo (taken orally, twice daily) plus standard treatment, both for 14 days.