Types of Opioids Used for Chronic Pain Relief

Opioids have long been used to treat severe pain, though their use in the management of chronic pain remains somewhat controversial. Some people can tolerate opioids for years without any adverse effects, while others may become physically dependent or even develop a tolerance with regular use. Like most medications, opioids work differently for everyone.

Opioids can have profound effects when not taken as prescribed. Your healthcare provider will work with you to determine the best medication for your pain.

This article explores what opioid medication is, types of opioids, and side effects. It also discusses non-opioid alternatives and how your healthcare provider will determine the right choice for you.

What Are Opioids?

Opioids are an analgesic, or medication used to control pain sensations. Because they are classified as narcotics, they are available by prescription only. Opioids work by attaching to specific receptors in the nervous system and changing how the brain perceives and interprets pain. Opioids may be given in the following ways:

• Intravenously: Small doses of opioids are injected, often via a pain pump, to provide short-term pain relief. IV opioids are commonly used after major surgeries, such as a hip replacement or spine surgery.
• Orally: Opioids may be taken by mouth in pill form or as a liquid, which is how most chronic pain medications are delivered. Oral opioids may be formulated to provide short-term or long-term pain relief for a few or several hours, respectively.
• Buccal/sublingual: In this form of administration, oral lozenges held in the cheek (buccal) or under the tongue (sublingual) dissolve and enter the bloodstream.
• Transdermally: Opioids may be applied to the skin in patch form, which slowly dispenses a dose of pain medication through the skin. Used for long-term pain relief, patches may be effective for a few days at a time.
• Via suppository: More often used for cancer pain than for other types of chronic pain, opioid suppositories release slow amounts of the analgesic over a period of up to 12 hours.

If you are prescribed opioids for chronic pain, chances are you will be using either an oral or patch form or a combination of the two.

Opioids Used to Treat Chronic Pain

Opioid medications bind to opioid receptor cells in the brain, spinal cord, and other parts of the body. Pain signals are blocked from reaching the brain when binding to these receptors. Some opioid medications include:

• Codeine: Codeine is a pain medication that is taken by mouth. It is short-acting, meaning it lasts only a few hours per dose. Codeine is often combined with acetaminophen, though it may also be administered with aspirin.
• Oxycodone: Oxycodone is available in short-acting and long-acting pain medication forms. It may be taken on its own or combined with other analgesics such as aspirin or acetaminophen.
• Fentanyl: Fentanyl is available as a short-acting pain medication in lollipop form, and it may be used for the management of breakthrough pain. A long-acting patch form is also available, effective for up to 72 hours.
• Hydrocodone: Hydrocodone, like codeine and oxycodone, may be combined with other analgesics such as aspirin or acetaminophen. It is a short-acting pain medication and is very similar to codeine.
• Hydromorphone: Hydromorphone is a short-acting opioid that is known to take effect quickly. It may be used in oral form, though injection and suppository forms are also available. Hydromorphone is sometimes used in place of morphine.
• Morphine: Morphine is one of the most effective opioids. Though available in a quick-release lozenge form, it is most often injected by a healthcare professional at a hospital or clinic.
• Methadone: Though it is commonly used as a weaning drug for some opioids or heroin, methadone is also helpful in the management of chronic pain. It is usually dosed every 8 to 12 hours.
• Oxymorphone: Oxymorphone is available in short-acting forms through injection or suppositories. An effective long-acting form for up to 12 hours is also available. Oxymorphone is sometimes used in place of morphine.
• Pentazocine: Pentazocine is similar to codeine and is a short-acting opioid. It is rarely used in its most potent form due to its tendency to cause confusion and anxiety, especially in seniors.
• Buprenorphine: Buprenorphine is another drug sometimes prescribed to aid opioid withdrawal. It may be used for severe pain relief as well. Oral, transdermal (patch), and injection forms are available.

Non-Opioid Alternatives for Chronic Pain

Before opioids are prescribed, most healthcare providers will recommend non-opioid medications to prevent the side effects and risks associated with opioid use. Although some of these medications may have potential side effects, they are typically more appropriate than opioids for long-term use. These include:

• NSAIDs: Non-steroidal anti-inflammatories help control pain and inflammation. Over-the-counter NSAIDs include Advil and Motrin (ibuprofen); Aleve and Naprosyn (naproxen); and Bayer, Ecotrin, and Bufferin (aspirin). Prescription-strength NSAIDs include Toradol (ketorolac), Voltaren (diclofenac), meloxicam, Daypro (oxaprozin), Nalfon (fenoprofen), and Indocin (indomethacin)
• Acetaminophen: Better known as Tylenol, acetaminophen is a pain reliever and fever reducer that works in the brain and spinal cord to reduce pain. The exact mechanism through which acetaminophen reduces pain is not well understood.
• COX-2 inhibitors: These medications block the enzyme cyclooxygenase-2 (COX-2), which is responsible for inflammation and pain commonly found in arthritis. The only COX-2 inhibitor currently on the market in the United States is Celebrex (celecoxib).
• Antidepressants: Some antidepressants show promise for use in people who experience chronic pain. In recent studies, duloxetine has shown the most promise, and milnacipran has shown great potential, although more studies need to be done.
• Anti-seizure medications: Certain anti-seizure medications can help with neuropathic pain. FDA-approved anti-seizure medications that are also approved for pain include Neurontin (gabapentin), Lyrica (pregabalin), and Tegretol (carbamazepine).

Opioid use may be considered when non-opioid analgesics have failed to provide pain relief. If these analgesics are not effective against your chronic pain, your healthcare provider may consider something stronger. Opioids vary in strength, and some may be combined with other pain medicines.

Side Effects of Opioids

Opioids carry side effects, some of which are mild and some of which are potentially life-threatening. Some potential side effects include:

• Constipation
• Dizziness
• Sleepiness
• Nausea
• Shallow breathing
• Loss of consciousness
• Slowed heart rate
• Dependence

Risks of Opioids for Chronic Pain

One of the single most significant risks of opioid use for chronic pain is developing a dependence and/or opioid use disorder.

Those with opioid dependence experience withdrawal symptoms when their opioid medication is discontinued. They may use more of the medication to achieve the same high feeling, which increases the risk of overdose.

Those who develop opioid use disorder use their medication in ways other than prescribed. When the prescribed opioids are not sufficient to produce a high, people with opioid use disorder may seek additional opioids by buying them illegally. This can sometimes lead to people turning to heroin, which produces similar effects but is often less expensive.

What Kind of Opioid Will Your Healthcare Provider Prescribe?

Thetype of opioid you are prescribed will depend on the type and quality of your pain. Unless you have tried other non-opioid medications without relief, your healthcare provider may not prescribe you opioids at all. If non-opioid analgesics have not been effective for you, your practitioner may start you on a mild opioid such as codeine. Or, he may try you on an opioid that is mixed with aspirin or acetaminophen.

If your pain is more severe, you may be given something stronger, such as oxycodone. Your healthcare provider may try both short-acting and long-acting forms to see what works best for your pain. He may also combine stronger opioids with other analgesics, depending on your needs.

Like most other pain medications, you may have to try more than one type of opioid or opioid combination before you find relief.

Summary

Chronic pain can be a complex condition to manage. Still, different types of opioid medications can help, in addition to non-opioid medications like NSAIDs, acetaminophen, anti-seizure medication, anti-depressants, and COX-2 inhibitors. It is essential to realize that opioid use, especially long-term, carries the risk of overuse and dependence. A healthcare provider should monitor the use of opioids carefully.