Opioids: What drug is used medically to relieve severe pain?

October 11, 2025 •

4 min read

Opioids, such as morphine and fentanyl, are recognized as the most potent class of analgesics, used medically to relieve severe pain that does not respond to other, less powerful medications. As powerful prescription drugs, they carry significant risks and must be used with caution under a healthcare provider's supervision.

Quick Summary

Opioids like morphine, fentanyl, and oxycodone are the main class of prescription medications used to treat severe pain. They alter the brain's pain perception but carry risks, including addiction, dependence, and respiratory depression, necessitating careful use and monitoring.

Key Points

Opioids are for severe pain: A class of potent drugs, including morphine, fentanyl, and oxycodone, are used medically for severe pain not managed by other medications.
Opioids carry high risk: Significant risks associated with opioid use include addiction, tolerance, physical dependence, and life-threatening respiratory depression.
Specific opioids for different uses: Morphine is often used post-surgery, fentanyl is highly potent for severe or chronic cases, and oxycodone treats moderate to severe pain.
Non-opioid alternatives exist: For many forms of pain, non-opioid medications (NSAIDs, acetaminophen) and non-pharmacological therapies (physical therapy, acupuncture) offer effective and safer alternatives or complementary treatments.
Multimodal pain management is key: Combining different approaches, including medication, physical therapies, and psychological support, is often the most effective strategy for managing severe and chronic pain.
Professional medical guidance is crucial: Due to the risks, opioids should only be used under the close supervision of a healthcare provider, and patients should be carefully monitored.

The Role of Opioids in Severe Pain Management

Pain is a complex medical issue, and for severe cases, powerful medication is often necessary. Opioids are a class of natural, semi-synthetic, and synthetic drugs that are the most potent prescription pain relievers available. They are reserved for moderate to severe pain, particularly in situations such as post-operative recovery, severe injury, and pain associated with advanced diseases like cancer. Opioids work by binding to opioid receptors on nerve cells in the brain, spinal cord, and other areas of the body, which blocks the transmission of pain signals and reduces the perception of pain. This mechanism of action, while highly effective, is also what contributes to the potential for abuse, dependence, and addiction.

Common Opioids for Severe Pain Relief

Several specific opioid drugs are used to medically relieve severe pain, differing in potency, duration of action, and administration methods. The choice of medication depends on the patient's condition, pain level, and tolerance.

Morphine: A naturally derived opioid often considered the benchmark for comparison with other opioids. It is used to treat both acute and chronic severe pain, including post-operative pain and cancer-related pain. It can be administered orally, intravenously, or epidurally.
Fentanyl: A synthetic opioid that is 50 to 100 times more potent than morphine. It is used for very severe pain, particularly for patients with opioid tolerance, and is available in transdermal patches for continuous, long-term pain management, as well as injections and lozenges.
Oxycodone: A semi-synthetic opioid prescribed for moderate to severe pain. It is commonly found in immediate-release formulations and extended-release tablets (OxyContin®) for around-the-clock pain control. It is sometimes combined with acetaminophen (Percocet®).
Hydrocodone: Used for moderate to severe pain and is most commonly combined with acetaminophen (Vicodin®) or ibuprofen. Extended-release formulations are also available.
Hydromorphone: A potent opioid used for moderate to severe pain. It is particularly used for opioid-tolerant patients and is available in oral, injectable, and rectal formulations.

Risks and Side Effects of Opioid Therapy

Despite their effectiveness, opioids are not without significant risks and side effects that require careful management by healthcare professionals.

Addiction and Dependence: Long-term use of opioids can lead to tolerance, dependence, and addiction. Tolerance means needing higher doses for the same pain relief, while dependence causes withdrawal symptoms if the medication is stopped suddenly. Addiction is a chronic brain disease characterized by compulsive drug-seeking behavior despite harmful consequences.
Respiratory Depression: This is a life-threatening side effect where breathing slows to dangerous levels. It is a major risk, especially at the start of treatment or when doses are increased. Co-administration with other depressants like alcohol increases this risk significantly.
Common Side Effects: Other common and manageable side effects include constipation, nausea, vomiting, drowsiness, and confusion. Constipation is particularly common and often requires a long-term management plan.

Comparison of Opioid and Non-Opioid Pain Management

To decide on the most appropriate treatment, healthcare providers weigh the benefits and risks of opioids against other options, especially for chronic pain. Multimodal strategies often combine different types of therapies to maximize pain relief while minimizing side effects.


Feature	Opioid Analgesics	Non-Opioid Pain Relievers (NSAIDs, Acetaminophen)	Complementary Therapies	Antidepressants/Anticonvulsants
Efficacy for Severe Pain	Very high, especially for acute and cancer-related pain	Limited efficacy; better for mild to moderate pain	Variable efficacy; often used alongside other treatments	Effective for neuropathic pain; long onset time
Risk of Addiction	High potential for addiction and dependence	Negligible risk of addiction	No risk of addiction	Negligible risk of addiction
Mechanism of Action	Bind to opioid receptors in the brain and spinal cord	Reduce inflammation or block pain signals in the CNS	Addresses physical and psychological aspects of pain	Quiets pain signals from damaged nerves; enhances pain inhibition
Common Side Effects	Constipation, nausea, drowsiness	Stomach issues (NSAIDs), liver damage (Acetaminophen)	Minimal, typically mild discomfort	Dizziness, drowsiness, nausea
Best for...	Short-term severe pain (surgery) or end-of-life care	Mild to moderate pain or inflammation	Chronic pain conditions; adjunct therapy	Nerve-related pain

Non-Pharmacological Approaches to Pain Management

Managing severe and chronic pain often involves more than just medication. Incorporating non-pharmacological treatments can improve overall function and quality of life while potentially reducing the reliance on opioids.

Physical Therapy: Exercise, massage, heat, and cold packs can help reduce pain and improve mobility.
Acupuncture: Some studies suggest acupuncture can help reduce the severity of pain by interrupting pain signals.
Psychological Therapies: Approaches like Cognitive Behavioral Therapy (CBT) can help patients develop coping strategies for chronic pain, addressing the emotional and mental aspects of their condition.
Spinal Cord Stimulation: This technique uses a device implanted near the spinal cord to deliver electrical signals that mask pain sensations.
Transcutaneous Electrical Nerve Stimulation (TENS): A non-invasive technique using low-voltage electrical currents to provide short-term pain relief.

Conclusion

What drug is used medically to relieve severe pain? The answer is a class of medications known as opioids, which include powerful drugs such as morphine, fentanyl, and oxycodone. They are highly effective for their intended purpose but must be prescribed and monitored carefully due to significant risks, including dependence, addiction, and respiratory depression. For many conditions, especially chronic pain, a combination of non-opioid medications and non-pharmacological treatments is safer and more effective for long-term management. The decision to use an opioid should always be made in consultation with a healthcare professional, considering the specific type and severity of pain and all available alternatives. For more information on opioid use and related topics, the National Institute on Drug Abuse is an authoritative resource.

National Institute on Drug Abuse (NIDA)

Frequently Asked Questions

The primary class of drugs used medically to relieve severe pain is opioids. Examples include morphine, fentanyl, and oxycodone, which are highly effective but carry a risk of addiction and other side effects.

Physical dependence is a normal biological adaptation where the body gets used to an opioid, leading to withdrawal symptoms if the drug is stopped suddenly. Addiction is a compulsive psychological need to seek and use a drug, even when it causes harm.

For many chronic pain conditions, opioids are not the ideal long-term solution due to the risks of tolerance, dependence, and addiction. Healthcare providers often prefer non-opioid medications and other therapies for chronic pain management.

Non-opioid options for severe pain can include nonsteroidal anti-inflammatory drugs (NSAIDs), certain antidepressants and anticonvulsants for nerve pain, and a variety of physical and psychological therapies such as physical therapy and acupuncture.

One of the most significant risks of opioid use is respiratory depression, a potentially fatal side effect where breathing becomes dangerously slow or shallow. The risk increases at the beginning of treatment or with higher doses.

Side effects like constipation, nausea, and drowsiness can often be managed. Constipation may require a stool softener, while nausea might be addressed with anti-emetics. A healthcare provider can also adjust dosages to minimize side effects.

Yes, but the dosage and use must be carefully determined and supervised by a doctor. Opioid use in children is subject to the same risks as adults, requiring meticulous monitoring.

Naloxone is a medication that can rapidly reverse an opioid overdose by blocking opioid receptors. It is available over-the-counter and is a crucial, life-saving tool for reversing life-threatening respiratory depression caused by an overdose.