Codeine is used to treat mild-to-moderate types of pain. The most common side effects of codeine are feeling sick (nausea), constipation, feeling sleepy, and dry mouth. Codeine belongs to a class of medications called opiate (narcotic) analgesics and to a class of medications called antitussives. When codeine is used to treat pain, it works by changing the way the brain and nervous system respond to pain. Codeine is a type of strong painkiller called an opioid. It's used to treat pain, for example after an operation or an injury. It's often used when other painkillers, such as paracetamol and ibuprofen, have not worked. Codeine can also be used to treat a dry or painful cough or diarrhoea. Codeine is a narcotic pain reliever (analgesic) used to treat mild to moderately severe pain frequently combined with Tylenol or aspirin. Common side effects include itching, rash, stomach pain, constipation, shortness of breath, nausea, lightheadedness, and dizziness. Codeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is commonly used as a recreational drug. Codeine is used to manage mild to moderate pain, where treatment with an opioid is appropriate, and when other pain treatments such as non-opioid pain medicines do not treat your pain well enough or you cannot tolerate them. Codeine is an opioid and considered a strong prescription pain medicine. What is codeine, and can it be addictive? Explore the answers along with insights on codeine overdose, withdrawal, detox, and treatment options. Uses What is codeine used for? Codeine is commonly used to treat mild to moderate pain. Codeine may also be used for other conditions as determined by your healthcare provider. Codeine reference guide for safe and effective use from the American Society of Health-System Pharmacists (AHFS DI). Codeine can cause serious unwanted effects if taken by adults, children, or pets who are not used to strong narcotic pain medicines. Make sure you store the medicine in a safe and secure place to prevent others from getting it.