Opioids and overdose risk Credit: Peter Dazeley / The Image Bank / Getty Images People who live with ongoing pain face daily challenges in getting on with their lives despite the pain. Among the many pharmaceutical and non-pharmaceutical treatments for persistent pain, opioids raise a lot of controversies because their possible severe side effects can sometimes overweight their benefits. Opioid medicines – such as morphine, codeine, oxycodone, methadone and others – can affect the brain to make people less aware of pain. But opioids also affect things other than pain levels, and many people taking these drugs long-term experience a lot of unwanted effects, some very serious.