For anyone wondering what are blues drugs used for, doctors prescribe M30 pills to people who need strong pain relief. The Blue pill oxycodone 30 mg en espanol is commonly given to those recovering from surgery or dealing with chronic pain conditions or pain related to cancer. It works by altering how the brain and central nervous system respond to pain, making the pain feel less intense. While effective for pain management, this medication should be used exactly as prescribed to avoid the risk of addiction and other serious side effects.