Long term side effects of using opium include damage to the internal organs and physical dependence. Opium addiction can set in after just a few weeks of using this drug and the subsequent withdrawal symptoms that occur when an individual is addicted to opium can be difficult and uncomfortable for the user. Many people continue to smoke opium simply to ward off the withdrawal symptoms that they feel when they don’t use the drug after physical dependence has set in. The best way to avoid all of the potentially dangerous side effects of opium is to avoid use of opium or it’s derivatives all together.