This document discusses guidelines for drug use during lactation. It begins by outlining principles from the Quran and Hadith regarding breastfeeding. It then discusses anatomy related to lactation and hormonal regulation. Guidelines for chemotherapy during lactation emphasize using drugs with minimal infant exposure and avoiding unnecessary drugs. Several classes of drugs are discussed, identifying those that are generally safe to use during lactation like beta-blockers, thiazides, ACE inhibitors, warfarin, inhaled asthma medications, and corticosteroids. Drugs that should be avoided include phenobarbital, primodone, and clonazepam. The document also covers stimulants and inhibitors of lactation.