Short-term effects of opioid use include decreased pain, euphoria, drowsiness, constipation and nausea, and long-term effects include physical dependence and addiction, according to the National Institute on Drug Abuse. Opioid use may also cause decreased respiration and decreased oxygen sent to the brain.
Opioids attach to the opioid receptors in a person's body to reduce pain perception, but their activity in the reward area in the brain also creates a pleasurable response in some people, states the National Institute on Drug Abuse. Overdose can cause severely decreased respiration and death. Although opioids are a safe, effective way to manage pain when taken as prescribed, regular long-term use can lead to dependence or addiction.
In cases of both dependence and addiction, patients may experience withdrawal symptoms if they suddenly reduce or stop taking opioids, confirms the National Institute on Drug Abuse. Withdrawal symptoms include muscle and bone pain, diarrhea, insomnia, vomiting, and restlessness. Users may also experience cold flashes, involuntary leg movements and goose bumps. Long-term opioid use can also affect brain function, as decreased breathing leads to hypoxia, or decreased oxygen in the brain. This can result in coma and permanent brain damage. Studies have shown that heroin users may experience a decrease in white matter in the brain, which can affect behavior regulation and decision making.