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Opioids (narcotic analgesics)

Medically reviewed by Carmen Pope, BPharm. Last updated on April 17, 2023.

Other names: narcotic analgesics, narcotics, opiates, opioid analgesics, opioids

What are opioids (narcotic analgesics)?

Opioids (narcotic analgesics) are a class of medicines that are used to provide relief from moderate-to-severe acute or chronic pain. They may also be called opiates, opioid analgesics, or narcotics. Analgesic is another name for a medicine that relieves pain. An opioid analgesic is an opioid that can be prescribed by a doctor to relieve pain.

Opioid analgesics are one of the most widely used analgesics for pain relief; however, they have been overused, overprescribed, and misused which has resulted in more than two million people in the U.S. alone having a substance misuse disorder involving prescription opioid analgesics.

Opioids work by binding to opioid receptors, which are part of the messenger system in our body that controls pain, and pleasurable and addictive behaviors. Opioid receptors are more abundant in the brain and spinal cord but are also located elsewhere in the body such as the stomach and the lungs. The main opioid receptor that opioids bind to is the mu receptor.

What are opioid analgesics used for?

In the past, opioid analgesics have been used for all types of pain, which may explain why there are so many people addicted to them today.

The most appropriate use of opioid analgesics is for the relief of short-term, intense pain, such as that occurring immediately after surgery or due to a medical condition.

Opioid analgesics may also be used to relieve pain due to cancer, or for palliative or end-of life care. They should only be used to treat other types of chronic pain under strict conditions and with close monitoring.

What are the differences between opioid analgesics?

Opioid analgesics differ in their structure, potency, and the way they are absorbed, distributed, metabolized and excreted within the body.

Some, like morphine and codeine were originally derived from plants. Others, such as heroin, hydrocodone, hydromorphone, oxycodone, and oxymorphone are made by modifying morphine and are called semi-synthetic. There are three main classes of opioids – those that are structurally like morphine (the phenanthrenes), those that resemble fentanyl (the phenylpiperidines), and those that resemble methadone (the phenylheptylamines).

Different opioid analgesics have different potencies, based on how strongly they bind to the opioid receptor (for example, fentanyl is 80 to 100 times stronger than morphine). This means that the dosages for one opioid may be significantly different from another. Although conversion charts exist (these tell you what dose of an opioid compares to the equivalent analgesic dose of morphine); these are only at best a guide because other variables, such as an individual’s genetics, play a part in how a person responds to a opioid.

If an opioid analgesic is deemed appropriate; codeine or tramadol should be tried first if the pain is mild-to-moderate. If the pain is unresponsive to these analgesics, or for more severe pain, then hydromorphone, morphine, or oxycodone should be considered. Fentanyl and methadone should only be used for severe pain that is unresponsive to other opioid analgesics.

Common opioid analgesics available in the U.S. include:

Name Route Onset of effect Duration of effect
alfentanil Intravenous (IV) 90 seconds 45-60 mins
codeine Oral 15-60 mins 3-4 hours
fentanyl IV Immediate 0.5-1h
Intramuscular (IM) 7-8 mins 1-2 hours
Buccal (through the gums)
Sublingual (SL)
5-15mins 4-6 hours
Transdermal patch (via the skin) 6h 72-96 hours
hydrocodone Oral 10-20 minutes 4-8 hours
hydromorphone Oral 15-30 mins 3-4 hours
IV 5 mins 3-4 hours
methadone Subcutaneous (SC) (under the skin) 15 mins 3-4 hours
morphine Oral 30-60 mins 3-6 hours (immediate-release)
8-24 hours (extended-release)
IV/SC 5-10 mins 4 hours
oxycodone Oral 10-15 mins 3-6 hours
oxymorphone Oral 30-60 mins (immediate-release)
1-2 hours (extended-release)
4-6 hours (immediate-release)
12 hours (extended-release)
IM/IV/SC 5-10 mins 3-6 hours
tramadol Oral 30-60 mins (immediate-release)
1-2 hours (extended-release)
4-6 hours (immediate-release)
24 hours (extended-release)

Are opioid analgesics safe?

There are serious risks associated with opioid analgesics including respiratory depression (unusually slow and shallow breathing), opioid-use disorder, and potentially fatal overdose.

Opioid-use disorder is defined as the repeated occurrence of at least two out of 11 specific opioid-associated problems, including using opioids in increased amounts or for longer than intended; continued use despite interference with daily activities; or still using while in hazardous situations. Severe opioid-use disorder is defined as a cluster of 6 or more problems and it can affect people from all educational and socioeconomic backgrounds.

Opioid analgesics are potentially addictive and the risk of becoming emotionally and physically dependent on them increases the more you take and the longer you take them for. When prescribed by a doctor and used for short periods of time, such as for less than five days for pain relief after surgery, the risk of becoming addicted to opioid analgesics is relatively low. The number of fatal overdoses from opioids continues to rise. 

When taken exactly as prescribed by a doctor, for short periods of time, for the relief of severe pain, and under strict monitoring, opioid analgesics are considered acceptable to use. However, they may still be associated with some severe side effects, despite proper use.

What are the side effects of opioid analgesics?

Opioid analgesics have many side effects, although people with cancer or terminal illness taking opioids for long periods of time may become tolerant to some of these side effects.

Drowsiness, sleepiness, or dizziness is common with most opioid analgesics. This can affect driving or a person's ability to operate machinery and perform other hazardous tasks. Alcohol may potentiate these effects.

Other commonly reported side effects include:

Withdrawal symptoms may occur when people who have been taking opioid analgesics abruptly stop taking them. Symptoms are like having the flu, and may include body aches, chills, depression, diarrhea, goose-bumps, headaches, high blood pressure, insomnia, irritability, a runny nose and sweats. Withdrawal symptoms usually last about a week.

References

  1. Drewes AM, Jensen RD, Nielsen LM, et al. Differences between opioids: pharmacological, experimental, clinical and economical perspectives. British Journal of Clinical Pharmacology. 2013;75(1):60-78. doi:10.1111/j.1365-2125.2012.04317.x.
  2. Busse, J. W., Craigie, S., Juurlink, D. N., Buckley, D. N., Wang, L., Couban, R. J., Agoritsas, T., Akl, E. A., Carrasco-Labra, A., Cooper, L., Cull, C., da Costa, B. R., Frank, J. W., Grant, G., Iorio, A., Persaud, N., Stern, S., Tugwell, P., Vandvik, P. O., & Guyatt, G. H. (2017). Guideline for opioid therapy and chronic noncancer pain. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 189(18), E659–E666. https://doi.org/10.1503/cmaj.170363
  3. Drug Overdose Death Rates. National Institute on Drug Abuse. 2023. https://nida.nih.gov/research-topics/trends-statistics/overdose-death-rates

 

List of Opioids (narcotic analgesics)

View by  Brand | Generic
Drug Name Avg. Rating Reviews
Dilaudid (Pro)
Generic name: hydromorphone
8.3
329 reviews
OxyContin (Pro)
Generic name: oxycodone
8.6
300 reviews
Nucynta (Pro)
Generic name: tapentadol
6.2
274 reviews
Belbuca (Pro)
Generic name: buprenorphine
4.5
247 reviews
Ultram (Pro)
Generic name: tramadol
6.2
230 reviews
Butrans (Pro)
Generic name: buprenorphine
6.3
229 reviews
Xtampza ER (Pro)
Generic name: oxycodone
3.6
164 reviews
Fentanyl Transdermal System
Generic name: fentanyl
7.7
107 reviews
MS Contin (Pro)
Generic name: morphine
8.0
98 reviews
Hysingla ER (Pro)
Generic name: hydrocodone
4.1
98 reviews
Opana (Pro)
Generic name: oxymorphone
8.0
88 reviews
Opana ER (Pro)
Generic name: oxymorphone
7.8
86 reviews
Nucynta ER (Pro)
Generic name: tapentadol
7.2
81 reviews
Stadol (Pro)
Generic name: butorphanol
5.9
76 reviews
Demerol (Pro)
Generic name: meperidine
9.4
75 reviews
Duragesic (Pro)
Generic name: fentanyl
8.4
72 reviews
Roxicodone (Pro)
Generic name: oxycodone
8.8
69 reviews
Zohydro ER
Generic name: hydrocodone
8.4
52 reviews
Kadian (Pro)
Generic name: morphine
8.1
49 reviews
Methadose (Pro)
Generic name: methadone
8.9
47 reviews
Ultram ER (Pro)
Generic name: tramadol
7.8
34 reviews
Methadone Diskets
Generic name: methadone
9.4
34 reviews
Exalgo (Pro)
Generic name: hydromorphone
7.8
34 reviews
Avinza
Generic name: morphine
8.3
33 reviews
Nubain (Pro)
Generic name: nalbuphine
7.1
28 reviews
Dolophine (Pro)
Generic name: methadone
9.5
24 reviews
Oxaydo (Pro)
Generic name: oxycodone
4.5
17 reviews
Actiq (Pro)
Generic name: fentanyl
9.1
16 reviews
Ryzolt
Generic name: tramadol
6.8
14 reviews
Fentora (Pro)
Generic name: fentanyl
9.3
14 reviews
Paregoric
Generic name: opium
9.6
13 reviews
Subsys (Pro)
Generic name: fentanyl
8.6
12 reviews
Dazidox
Generic name: oxycodone
3.0
11 reviews
Dilaudid-HP (Pro)
Generic name: hydromorphone
7.0
9 reviews
Talwin
Generic name: pentazocine
6.3
8 reviews
MorphaBond ER (Pro)
Generic name: morphine
2.5
8 reviews
Darvon
Generic name: propoxyphene
7.8
8 reviews
Sublimaze (Pro)
Generic name: fentanyl
7.8
6 reviews
OxyIR
Generic name: oxycodone
8.2
6 reviews
Buprenex (Pro)
Generic name: buprenorphine
8.4
6 reviews
Roxicodone Intensol
Generic name: oxycodone
10
5 reviews
Oramorph SR
Generic name: morphine
6.0
5 reviews
Oxyfast
Generic name: oxycodone
10
4 reviews
Duramorph (Pro)
Generic name: morphine
2.0
4 reviews
Meperitab
Generic name: meperidine
9.7
3 reviews
Levo-Dromoran
Generic name: levorphanol
7.0
3 reviews
Oxydose
Generic name: oxycodone
8.0
2 reviews
Lazanda (Pro)
Generic name: fentanyl
8.5
2 reviews
Infumorph (Pro)
Generic name: morphine
9.0
2 reviews
Abstral (Pro)
Generic name: fentanyl
4.0
2 reviews
Palladone (Pro)
Generic name: hydromorphone
10
1 review
ConZip (Pro)
Generic name: tramadol
9.0
1 review
Vantrela ER
Generic name: hydrocodone
No reviews
Ultiva (Pro)
Generic name: remifentanil
No reviews
Sufenta
Generic name: sufentanil
No reviews
Rybix ODT
Generic name: tramadol
No reviews
RoxyBond (Pro)
Generic name: oxycodone
No reviews
Roxanol-T
Generic name: morphine
No reviews
Roxanol
Generic name: morphine
No reviews
RMS
Generic name: morphine
No reviews
Qdolo (Pro)
Generic name: tramadol
No reviews
Oxecta
Generic name: oxycodone
No reviews
Onsolis
Generic name: fentanyl
No reviews
Olinvyk (Pro)
Generic name: oliceridine
No reviews
Numorphan
Generic name: oxymorphone
No reviews
Mitigo (Pro)
Generic name: morphine
No reviews
Ionsys
Generic name: fentanyl
No reviews
ETH-Oxydose
Generic name: oxycodone
No reviews
Duramorph PF
Generic name: morphine
No reviews
Dsuvia (Pro)
Generic name: sufentanil
No reviews
DepoDur
Generic name: morphine liposomal
No reviews
Astramorph PF (Pro)
Generic name: morphine
No reviews
Arymo ER (Pro)
Generic name: morphine
No reviews
For ratings, users were asked how effective they found the medicine while considering positive/adverse effects and ease of use (1 = not effective, 10 = most effective).

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.