Discovered in 1832, Codeine is an opiate used for the relief of moderately severe pain such as after an injury, or operation. Plus, it is usually used when other milder painkillers such as paracetamol or non-steroidal anti-inflammatory medicines don’t work well enough. It is worth noting that the group of medicines to which Codeine belongs is called opioid painkillers. Basically, these medicines act on your brain and nervous system to lessen the way you feel pain. In other words, when codeine is used to treat pain, it works by changing the way the brain and nervous system respond to pain. And when codeine is used to reduce coughing, it works by decreasing the activity in the part of the brain that causes coughing. Besides, other pain relievers such as paracetamol and NSAIDs may also be used with codeine to ensure greater benefit. When it comes to its side effects, Codeine can cause vomiting, constipation, itchiness, lightheadedness, and drowsiness. As for its serious side effects, they may include breathing difficulties and addiction. And whether its use in pregnancy is safe is actually still unclear. Care should be used nonetheless during breastfeeding, as it may result in opiate toxicity in the baby. Although it can be taken on an empty stomach, taking codeine with food can help prevent feelings of sickness which can occur with the first few doses.