Side effects and signs of misuse
Many opioids are potent. Pharmaceutical fentanyl, for instance, is 50–100 times as strong as morphine. Illicit fentanyl, which other drugs are sometimes laced with, is highly variable and dangerous, with stronger side effects and greater overdose risk than heroin.
Opioids mask pain and induce feelings of euphoria, intense calm, and sleepiness. Other common short-term side effects of opioids include confusion, slowed or stopped breathing, sickness and vomiting, and gastrointestinal issues such as constipation. Long-term use of these substances can cause dependence, heart and lung infections, and muscle pain.
Stopping use of opioids can cause intense, flu-like withdrawal symptoms. Preventing the onset of these ill feelings can lead to continued, long-term opioid use and dependence, a condition sometimes called opioid use disorder.
Use of opioids can lead to serious harm and even death. Consumption of illegally manufactured fentanyl — which may be sold as counterfeit prescription opioids or added to cannabis, cocaine, heroin, or methamphetamine — is driving up rates of opioid overdose and death. Heroin is also a highly addictive drug; 23% of people who use it develop a dependence on it.
These additional factors could increase your risk of misusing, becoming dependent on, or facing serious harm from opioids:
- Age, lifestyle, and medical history. Dependence is more likely if you use or have used other drugs, have an untreated mental illness, or live in a situation that enables drug misuse. The rate of nonmedical opioid use is highest among people ages 18 to 25, and most people who misuse prescription opioids start using the drug in their early to late 20s. Prescription opioid overdose deaths occur mostly among people aged 25 to 54.
- Long-term use. Using opioids for even a few days raises your risk of becoming dependent. An estimated 1 in 4 people receiving prescription opioids long term in a primary care setting become dependent, according to research summarized by the Centers for Disease Control and Prevention (CDC).
- High dosage. Taking a higher dose comes with a greater risk of dependence than taking a lower dose does, but even taking a low dose is risky, according to CDC prescribing guidelines.
- Extended-release formulations. Dependence is more common with drugs that act over a longer period than with those that act more immediately, CDC guidelines say.
