Opioid (Narcotic) Pain Medications

Medically Reviewed by Jabeen Begum, MD on June 14, 2024
Written by Stephanie Watson, Alyson Powell Key
7 min read

When you have a mild headache or muscle ache, an over-the-counter pain reliever is usually enough to make you feel better. But if your pain is more severe, your doctor might recommend something stronger — a prescription opioid.

Opioids are a type of narcotic pain medication. They can have serious side effects if you don't use them correctly. For people with an opioid addiction, the problem often starts with a prescription.

Types of opioid drugs

Opioids are classified into three groups:

  • Natural alkaloidsoriginate directly from the opium poppy plant. Examples include morphine and codeine.
  • Semi-synthetic opioids are natural alkaloids chemically modified to enhance their properties or create new drugs. Examples include oxycodone, hydrocodone, and heroin.
  • Synthetic opioids are entirely synthesized without relying on natural alkaloids. Examples include fentanyl, tramadol, and methadone.

If you need to take opioids to control your pain, here are some ways to make sure you're taking them as safely as possible.

Opioid drugs bind to opioid receptors in the brain, spinal cord, and other areas of the body, especially receptors related to pain and pleasure. They tell your brain you’re not in pain and release large amounts of dopamine, the "feel-good" hormone, throughout your body.

Doctors prescribe them to treat moderate to severe pain that may not respond well to other pain medications.

Agonist vs. antagonist opioids

 "Agonist" and "antagonist" are terms used to describe how opioids interact with opioid receptors in your body.

Agonist

This type of drug activates specific receptors in the brain. Full agonist opioids completely activate these receptors, leading to a strong opioid effect. Partial agonist opioids also activate these receptors but not as fully as full agonists do.

Antagonist

An antagonist is a drug that blocks opioids by attaching to the receptors without turning them on. Antagonists don't produce any opioid effects and prevent full agonist opioids from working.

List of opioid drugs

Opioid drugs include:

Your doctor can prescribe most of these drugs as a pill. Fentanyl is available in a patch. A patch allows the medication to be absorbed through the skin.

You'll need a prescription from your doctor before you start taking opioids, and they can adjust the dose as needed to help control pain. Doctors typically prescribe opioids for the following conditions:

  • Moderate to severe pain
  • Pain after surgery
  • Pain during cancer treatment
  • An incurable illness
  • Serious trauma or injury
  • Chronic pain conditions
  • Breakthrough pain

While you're on opioid pain medications, check in with your doctor regularly. Your doctor will need to know:

  • How your pain is responding to the drug
  • Whether you're having any side effects
  • Whether you have any potential interactions or medical conditions that could make you more likely to have side effects, such as sleep apnea, alcohol use, or kidney problems
  • Whether you're taking the drug properly

Never change or stop taking any opioid medicine without first checking with your doctor. If a pain medication isn't working as well as it should, your doctor may switch you to a different dose — or add on or try another drug.

Doctors prescribe pain medicine based on how serious your pain is on a scale of 1 to 10: no pain (0), mild (1-3), moderate (4-6), or severe (7-10). Some scales use happy or sad faces to show pain levels for those who struggle with numbers.

Opioid tolerance

After taking opioid pain medication for a while, you might find that you need more and more of the drug to achieve the same effect in easing pain. This is called tolerance. It's not the same as addiction, which involves a compulsive use of a drug. Opioid tolerance happens because opioid receptors in the brain become less sensitive with continued use. To manage tolerance, your doctor may adjust your opioid dose, switch you to a different medication, prescribe extra pain treatments such as non-opioid medications or physical therapy, and watch you closely.

One of the reasons why your doctor needs to manage pain medications so closely is that they can cause side effects, such as:

Gastrointestinal problems. You may have nausea and vomiting when you start taking opioids. It often passes after a few days. Try lying down for an hour or so after taking a dose, or ask your doctor for an over-the-counter or prescription nausea remedy.

Constipation is a common problem when you take opioids. They cause food to move more slowly through your system, which results in harder stools that don’t pass as easily. If you start having trouble:

  • Don’t wait more than 2 days without a bowel movement before getting in touch with your doctor.
  • Drink more water. This alone helps some people with mild constipation. But others may have to do more. Having a hot drink in the morning can get things moving through your gastrointestinal tract. Avoid drinks with caffeine, such as coffee and tea, and instead try hot water with lemon or herbal tea.
  • Ask if other drugs may help. Your doctor may recommend a stool softener or laxative that you can buy at the drugstore. Other drugs are available by prescription. Lubiprostone (Amitiza), methylnaltrexone (Relistor), naldemedine (Symproic), and naloxegol (Movantik) are approved to treat constipation due to opioid use in those with chronic pain.

Cognitive issues. Some people just don’t feel like themselves when they start taking opioids. You may have:

  • Trouble staying focused
  • Drowsiness
  • "Foggy" feeling or trouble thinking clearly
  • Slow reflexes

Don’t drive or operate heavy machinery while on opioids. It may take a week or more for you to start feeling normal again.

Make sure your doctor knows all of the other medicines you're taking. That includes:

  • Prescription drugs
  • Over-the-counter drugs
  • Herbal supplements

Respiratory problems. Opioids can cause respiratory depression by slowing down your involuntary breathing rate controlled by the brain. In serious cases, this can lower the amount of oxygen in the blood. When opioids cause respiratory depression, both the breathing rate and oxygen levels will be low.

Sexual dysfunction. Long-term opioid use can lead to hormonal problems that cause conditions such as low sex hormone levels in both men and women. These hormonal effects are likely related to opioid dosage and can cause:

  • Missed periods in women
  • Lower sex drive in both men and women
  • Trouble getting or keeping an erection in men
  • Trouble conceiving

Allergic reactions. Opioids can trigger allergic reactions in some people. You may have nausea, vomiting, itching, low blood pressure (hypotension), and constipation.

Opioids can be dangerous if you take them with alcohol or with certain drugs such as:

  • Some antidepressants and anxiety medications (particularly benzodiazepines such as alprazolam, clonazepam, and lorazepam)
  • Some antibiotics
  • Sleeping pills

Combining opioid drugs with central nervous system (CNS) depressants, such as benzodiazepines, alcohol, or xylazine, can raise your chances of a life-threatening overdose.

When you use opioid medication over an extended period, you can have dependence. This can happen when your body becomes so used to the drug that if you abruptly stop taking it, you get withdrawal symptoms.

You can also get a serious addiction to opioid pain medications. People who are addicted compulsively seek out pain medications. Their behavior usually leads to negative consequences in their personal lives or workplace. They might take someone else’s pills or buy them off the street, which is especially dangerous since those drugs are often laced with lethal amounts of fentanyl. Learn more about what can happen when opioid addiction goes untreated.

If you are having a problem with addiction, you need to see your doctor or an addiction specialist.

Doctors usually schedule regular check-ins for people who use narcotics to manage pain. They do this to keep an eye on how well the medicine is working and any side effects. During these check-ins, your doctor will ask how much pain you're in, look for any bad reactions to the medicine, and make changes to your treatment plan if needed.

Doctors also combine short-term opioid therapy with other methods to manage pain, such as physical therapy, mindfulness practices, or non-opioid medications.

Opioid withdrawal

When you're ready to stop taking opioids, your doctor may wean you off them slowly — if you have taken them for a long time — to give your body time to adjust. Otherwise, you may have withdrawal symptoms, including:

  • Hot and cold flashes
  • Feeling anxious or irritable
  • Opioid cravings
  • Nausea and throwing up
  • Diarrhea
  • Appetite loss
  • Shaking
  • Watery eyes, runny nose, and sneezing
  • Yawning
  • Trouble sleeping

Talk to your doctor if you've stopped taking an opioid and are having these symptoms.

Opioids can make a dramatic difference to people with moderate to severe pain, but they aren’t always the right choice. Discuss the necessity of using them with your doctor. If you take them, follow your doctor's instructions carefully. If your pain isn't related to cancer, talk with your doctor regularly about whether you need to keep taking opioids. If you need to continue taking them, lowering the dose or changing the type of opioid may help prevent problems.

Over-the-counter pain relievers can usually manage mild pain, but for severe pain, doctors may prescribe opioids. Opioids are powerful narcotic medications that ease pain by binding to receptors in the brain and spinal cord. But, they carry significant risks, including side effects such as nausea, constipation, cognitive issues, and potential addiction. Proper use and close medical supervision are crucial to lowering these risks.

Follow your doctor's guidance, report any side effects, and avoid combining opioids with certain other medications or alcohol. Long-term use can lead to tolerance, dependence, and addiction, so regular check-ins with your doctor are essential for safe opioid use and potential weaning off the medication.