The present invention relates to methods for treating, preventing, or reducing the risk of microbial infections while minimizing adverse gastrointestinal effects using a two-stage dosing regimen comprising about 1 to about 7 days of intravenous administration followed by about 1 to about 14 days of oral administration of an antimicrobial agent.本發明是關於使用兩階段給藥方案治療、預防微生物感染或降低微生物感染風險同時使不良胃腸作用降至最低的方法,包括約1天至約7天靜脈內投與抗微生物劑,隨後約1天至約14天經口投與抗微生物劑。