Understanding The Different Types of Opioids

Opioids vs. Opiates

The opioid class includes painkillers that doctors use to reduce pain. The term opioid can refer to prescription painkillers like OxyContin, synthetic painkillers like fentanyl, and illegal drugs like heroin.

An opiate is different. The term opiate refers to natural drugs like morphine—not synthetic drugs like fentanyl.

In other words, all opiates are opioids, but not all opioids are opiates.

What Are Opioids?

Opioids are a class of painkillers that interact with a person’s opioid receptors, reducing pain and giving a person a sense of euphoria. Included in this class of drugs are several illegal drugs with no or very few accepted medical uses, such as heroin, as well as prescription medications that are commonly used to help patients manage pain, such as oxycodone and morphine.

Opioids are a class of painkillers that interact with a person’s opioid receptors, reducing pain and giving a person a sense of euphoria. Included in this class of drugs are several illegal drugs with no or very few accepted medical uses, such as heroin, as well as prescription medications that are commonly used to help patients manage pain, such as oxycodone and morphine.

These are some of the many opioids:

• Benzhydrocodone
• Buprenorphine
• Carfentanil
• Codeine
• Fentanyl
• Heroin
• Hydrocodone
• Hydromorphone (Dilaudid)
• Levorphanol tartrate
• Methadone
• Morphine
• Opium
• Oxycodone
• Oxymorphone
• Percocet
• Pethidine
• Sufentanil
• Tapentadol
• Tramadol

The many different types of opioids can be broken into two classes: long-acting and short-acting. Several studies published in 2008 found no difference in the addiction potential between these two types of drugs. People tend to “like” them at the same rate and use them in a similar manner to get high.

However, understanding what separates a long-acting drug from a short-acting one can be helpful.

Long-Acting Opioids

Opioids that last a long time in the body are called long-acting opioids. They may also be referred to as extended-release or controlled-release opioids.

These are common long-acting opioids:

Morphine (Controlled-Release & Extended-Release)

Morphine is a painkiller approved by the U.S. Food and Drug Administration (FDA) to treat acute or chronic pain that hasn’t responded to other therapies (like aspirin). It shouldn’t be used during pregnancy or in people taking medications like MAOIs.

Morphine comes in many forms. It is often used as the “standard” to compare other opioids to in terms of strength and risk.

Controlled-release (Kadian) and extended-release (Avinza) morphine are similar in many ways. Controlled-release capsules are typically taken at a starting dose of 20 mg every 12 or 24 hours, and extended-release capsules are taken at a dose of 30 mg once a day.

Oxycodone (Controlled-Release)

Controlled-release oxycodone, sold under the name OxyContin, is FDA-approved for people struggling with pain that requires around-the-clock treatment that hasn’t responded to other forms of therapy. Doctors are encouraged to start with the smallest dose possible to treat their patients and to use it for short periods.

People with gastrointestinal obstructions, severe respiratory depression, and pregnancy shouldn’t use OxyContin.  

Oxycodone generally comes in 10, 20, 40, and 80 mg strengths. Patients typically start at 10 mg every 12 hours.

Oxymorphone (Extended-Release)

Oxymorphone is FDA-approved for pain severe enough that it requires around-the-clock therapy that hasn’t responded to other types of treatment. Doctors are encouraged to try other medications and therapies first before using oxymorphone.

People with significant respiratory depression, asthma, gastrointestinal obstructions, or liver problems shouldn’t use this drug. Since the pills are large, people with difficulty swallowing may be unable to use this drug safely.

This kind of oxymorphone, sold as Opana ER, comes in 5, 10, 20, 30, and 40 mg strengths. Patients typically start at 5 mg every 12 hours.

Hydromorphone (Extended-Release)

Hydromorphone extended-release pills are FDA-approved for the management of severe pain that requires around-the-clock treatment that hasn’t responded to other therapies. It’s not for as-needed pain control or acute pain. Instead, it’s designed to help people who have already used opioid drugs for some time and need even more relief for daily pain.

Hydromorphone pills shouldn’t be used in older people with heart disease, and they can interact with central nervous system depressants. Since it can cause severe respiratory depression, it shouldn’t be used in people with head injuries or those with impaired consciousness.

Sold as Exalgo ER, this medication comes in 8, 12, 16, and 32 mg strengths. Patients are instructed to take their pills once per day.

Methadone

Methadone comes in two formats.

Dolophine is FDA-approved to treat pain that’s severe enough that it requires around-the-clock care. It comes in 5 mg and 10 mg strengths, and it’s not right for people with asthma, gastrointestinal obstructions, or a hypersensitivity to methadone.

Methadone is also prescribed as an opioid use disorder treatment. By administering methadone in a controlled setting, doctors can help a patient reduce their cravings and make it easier to resist misusing drugs.

Fentanyl (Patch)

Fentanyl patches, sold under the brand name Duragesic, are FDA-approved for severe pain that requires around-the-clock care that hasn’t responded to other therapies. People who can’t swallow pain pills or accept pain injections might benefit from fentanyl therapy.

Fentanyl isn’t designed for people who haven’t used opioids before, as it’s too strong. It’s also not made for mild or transient pain. People with asthma, gastrointestinal problems, or fentanyl sensitivity shouldn’t use this powerful drug.

Buprenorphine 

Buprenorphine is an unusual opioid in that it has a ceiling effect, where a person doesn’t feel a continually stronger effect the more one uses. With that said, it still does have some abuse potential, although the transdermal implant option is difficult to abuse.

Buprenorphine is commonly used to treat opioid use disorder — both on its own and in combination medications like Suboxone (buprenorphine/naloxone).

Sold as Butrans, the patches come in strengths of 5, 10, and 20 mcg/hr, with the starting dose and dosing interval typically at 5 mcg applied every 7 days.

Short-Acting Opioids

Short-acting opioids last a shorter time in the body and typically cause a more intense effect in the user.

Common short-acting opioids include the following:

Dihydrocodeine

Dihydrocodeine is a semisynthetic opioid, meaning it is created with a process that begins with compounds from natural sources that are further synthesized into a different drug. It has a duration of action lasting between 3 and 6 hours. It is significantly less potent than morphine.

Pethidine

Pethidine has a duration of action that lasts between 2 to 4 hours. It is only slightly more potent than dihydrocodeine.

Hydrocodone

Hydrocodone has a duration of action that lasts 4 to 8 hours. It is about two-thirds as potent as morphine. 

Oxycodone

Oxycodone is slightly more potent than morphine, with a duration of action lasting about 3 to 4 hours.

Hydromorphone

Hydromorphone is an opioid that is significantly more potent than morphine, with manufacturers recommending one consider it 5 to 7.5 times more potent as morphine. Its effects last about 4 to 5 hours.

Buprenorphine 

Short-acting buprenorphine acts similarly to its long-acting counterpart, with a similar ceiling effect. While technically more potent than morphine by a significant degree, it has a much lower abuse and harm potential in practical terms.

Heroin

Heroin is one of the most notorious opioids, known (correctly) as an addictive and dangerous drug that is more potent than morphine.

Because it is generally produced illegally, it is also very common for heroin to be mixed with other substances. These mixtures can make the drug’s effect unreliable for a user, with varying strength, addictiveness, and danger depending on what a dealer has cut the heroin with.

Fentanyl

Short-acting fentanyl is a potent, dangerous drug with high abuse and addiction potential. It can be as much as 100 times stronger than morphine, and it can easily be deadly to a first-time user who underestimates its strength.

Fentanyl is frequently mixed with heroin, which a dealer may not inform a buyer about. 

Understanding the Strength of Opioids

Again, the strength of opioids varies. Morphine is a fairly strong opioid with abuse potential. It is carefully controlled, but it is overall middling in strength compared to many other opioids.

For context, morphine is over 200 times stronger than ibuprofen in terms of pain relief. However, remember that ibuprofen isn’t an opioid.

Comparable Opioids

Some opioids with comparable strength to morphine include hydrocodone, oxycodone, and codeine. Hydrocodone is about as strong as morphine, and oxycodone is about 50 percent stronger. Codeine is about three times as potent, which is significant but much less than some of the drugs we discuss below. 

Strongest Opioids

Heroin, buprenorphine, and fentanyl are all significantly stronger than morphine, but that grouping of drugs is somewhat misleading. Because of its ceiling effect, buprenorphine is not really comparable to heroin and fentanyl, and it often plays a key role as part of an opioid addiction treatment program.

Unfortunately, those other two drugs are commonly misused. Many people imagine heroin when they think of highly addictive, potent opioids being sold and used on the street, but fentanyl is significantly more potent and sometimes mixed in with heroin to make it more addictive.

One of the single strongest opioids with any kind of legitimate use is carfentanil, which is about 10,000 times stronger than morphine and extremely dangerous to humans in essentially any dose. It is used as a painkiller for very large animals, such as elephants. Sometimes, carfentanil is mixed with heroin and sold on the streets, resulting in an extremely potent, dangerous street drug.

Opioid Facts & Statistics to Consider

In 2022, more than 131,000,000 opioid prescriptions were dispensed in the United States. That represents a drop from 2017, when the total number of dispensed prescriptions was larger than 153,000,000.

Among people 12 and older in 2022, 8.9 million people (or 3.2% of the population) misused opioids at least once.

More than 75% of drug overdose deaths in 2021 involved an opioid. Researchers say many of these deaths can be attributed to synthetic opioids like tramadol and fentanyl.

Overdose deaths can involve only a single opioid medication, but they are often the result of a person mixing other substances with opioids, such as alcohol. Experts say polysubstance use is an increasing problem. For example, about 40% of overdose deaths involving illegally made fentanyl in 2020 also involved stimulants.

Unfortunately, the opioid epidemic is not under control, even as awareness of the issue spreads among medical practitioners. A steady rise in opioid deaths can be seen over time following a pattern of three waves:

• Wave 1 — 1999: The initial rise in opioid overdose deaths
• Wave 2 — 2010: The beginning of a spike in heroin overdose deaths
• Wave 3 — 2013: The beginning of a spike in synthetic overdose deaths, which continues to trend upward as of 2022

Opioid Potency 

The following is a chart for easy reference regarding the potency of several of the most commonly misused opioids and how they compare in potency to morphine. The two opioids in bold, heroin and carfentanil, have essentially no medical use for humans (although heroin was originally designed for medical purposes).

Medically Reviewed By Dr. Alison Tarlow

Dr. Alison Tarlow is a Licensed Clinical Psychologist in the States of Florida and Pennsylvania, and a Certified Addictions Professional (CAP). She has been a practicing psychologist for over 15 years. Sh... Read More