Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (664 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Agents that induce narcosis. Narcotics include agents that cause somnolence or induced sleep (stupor); natural or synthetic derivatives of opium or morphine or any substance that has such effects. They are potent inducers of analgesia and opioid-related disorders.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Narcotic; Narcotic Analgesics; Analgesics, Narcotic; Narcotic Effect; Effect, Narcotic; Narcotic Effects; Effects, Narcotic.
Where it fits in the MeSH classification
- Broader topics
- Central Nervous System Depressants; Analgesics
- Narrower topics
- Analgesics, Opioid
- See also
- Receptors, Opioid; Narcotic-Related Disorders
Related concepts
- Narcosis
- Stupor
- Opium
- Morphine
- Analgesia
- Opioid-Related Disorders
Research landscape
PubMed indexes 87,030 records tagged with the MeSH heading “Narcotics” (counts retrieved 2026-10-29). 26,649 of them (30.6%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 27,367 records.
Reviews account for 12,344 records (14.2%) and meta-analyses for 1,479. Randomized controlled trials number 10,223 (11.7%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 14,261 |
| 2000-2009 | 18,753 |
| 2010-2019 | 27,367 |
| 2020 onward | 26,649 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 12,344 | 14.2% |
| Meta-analyses | 1,479 | 1.7% |
| Randomized controlled trials | 10,223 | 11.7% |
Method: PubMed query "Narcotics"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in pharmacology
Drug evidence builds in layers: laboratory pharmacology describes how a compound acts, pharmacokinetic studies describe how the body handles it, and randomized trials test whether it helps and what harms it causes. Post-marketing surveillance and observational studies reveal rarer adverse effects but cannot prove causation. This page is educational and is not a recommendation to start, stop or change any medicine; decisions about treatment belong with a qualified clinician.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| A µ-opioid receptor superagonist analgesic with minimal adverse effects | 2026 | Research article Design not recorded in structured metadata | 7 | cc by PMID 41922775 · DOI · PMC13128446 |
| Effects of Opioids, Benzodiazepines, Gabapentinoids, and Antidepressants on Fracture Risk in Alcohol-Related Cirrhosis | 2026 | Research article Design not recorded in structured metadata | 3 | cc by PMID 42076874 · DOI · PMC13136785 |
| Association of prenatal exposure to opioids, cannabis, and polysubstance use with cord blood DNA methylation patterns in a multiancestry cohort | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 42643049 · DOI · PMC13523970 |
A µ-opioid receptor superagonist analgesic with minimal adverse effects [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Developing safe and effective pain medications is an ongoing challenge for human health.
- Closing excerpt
- These results provide novel insights about MOR and nitazene pharmacology, have important implications for pain and addiction treatment, and challenge the prevailing dogma that high-efficacy MOR agonists cannot constitute safe and effective therapeutic agents.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (198 words)
Developing safe and effective pain medications is an ongoing challenge for human health. Agonists for the µ-opioid receptor (MOR) are essential pain medications, but their high intrinsic efficacy also induces adverse side effects, including respiratory depression, constipation, tolerance, dependence, withdrawal and addiction1-7. Strategies to limit adverse effects traditionally include developing MOR agonists that have low intrinsic efficacy or that preferentially activate G-protein signalling over β-arrestin signalling8. Here we identify a novel MOR agonist with supramaximal intrinsic efficacy and a unique pharmacological profile that produced effective analgesia in rodents with minimal adverse effects. N-desethyl-fluornitrazene (DFNZ) was derived from a class of synthetic benzimidazole opioids called nitazenes. DFNZ has impaired brain penetrance, a unique spatiotemporal MOR cellular signalling profile, and diminished efficacy at the MOR-galanin 1 receptor (GAL1) heteromer. DFNZ does not induce respiratory depression, tolerance or MOR downregulation after repeated exposure. Compared with other MOR agonists, DFNZ has limited effects on dopamine neurotransmission in nucleus accumbens and weaker reinforcing effects in the drug self-administration procedure. These results provide novel insights about MOR and nitazene pharmacology, have important implications for pain and addiction treatment, and challenge the prevailing dogma that high-efficacy MOR agonists cannot constitute safe and effective therapeutic agents.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41922775 · DOI · PMC13128446
Effects of Opioids, Benzodiazepines, Gabapentinoids, and Antidepressants on Fracture Risk in Alcohol-Related Cirrhosis [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundPatients with alcohol-related liver cirrhosis (ALD cirrhosis) have an increased risk of falls and fractures.
- Closing excerpt
- Precautionary measures are recommended when initiation of these drugs is indicated.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (238 words)
BackgroundPatients with alcohol-related liver cirrhosis (ALD cirrhosis) have an increased risk of falls and fractures. Opioids, benzodiazepines, gabapentinoids, and antidepressants are known to increase fall risk.AimsWe aimed to determine the effects of opioids, benzodiazepines, gabapentinoids, and antidepressants on fracture risk in ALD cirrhosis.MethodsUsing Danish nationwide registries, we identified all patients diagnosed with ALD cirrhosis in 2000-2023 and their subsequent hospitalisations for fracture. Redeemed prescriptions defined exposure to opioids, benzodiazepines, gabapentinoids, and antidepressants. We applied Cox and Poisson regression to estimate fracture risks with and without exposure, adjusting for confounders. To minimise confounding, we also used a self-controlled case-crossover design.ResultsAmong 24 743 patients with newly diagnosed ALD cirrhosis, the 5-year fracture risk was 19.0% (95% CI: 18.4%-19.4%). Fracture risk was increased during the first 30 days after initiation of opioids (adjusted hazard ratio [aHR]: 3.20, 95% CI: 2.30-4.45), benzodiazepines (aHR: 2.17, 95% CI: 1.37-3.76), or gabapentinoids (aHR: 2.43, 95% CI: 1.66-3.55), whereas antidepressant initiation did not affect fracture risk (aHR: 1.07, 95% CI: 0.62-1.84). Similar within-person results were obtained using the self-controlled design. Notably, the risk-increasing effects of opioids, benzodiazepines, and gabapentinoids decreased with the duration of exposure, and none of the drugs increased fracture risk if the patient had been using them for more than 365 days.ConclusionsIn ALD cirrhosis, fracture risk is increased when treatment with opioids, benzodiazepines, or gabapentinoids is initiated, but not with long-term use. Precautionary measures are recommended when initiation of these drugs is indicated.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42076874 · DOI · PMC13136785
Association of prenatal exposure to opioids, cannabis, and polysubstance use with cord blood DNA methylation patterns in a multiancestry cohort [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Blood DNA methylation patterns are highly predictive of prenatal exposure to smoking, and differential methylation has been associated with maternal alcohol use.
- Closing excerpt
- These CpGs provide biologic insights for reducing the impact of substance exposure, and these findings may serve as a biomarker of prenatal substance exposure for future studies and potential clinical utility.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (228 words)
Blood DNA methylation patterns are highly predictive of prenatal exposure to smoking, and differential methylation has been associated with maternal alcohol use. We extended this to determine whether DNA methylation patterns in cord blood are associated with prenatal exposure to opioids, cannabis, and polysubstance use. We also evaluated whether DNA methylation patterns have predictive utility. We examined 932 mother-child pairs in the Boston Birth Cohort between 1998 and 2020 with cord blood DNA methylation data. For each substance self-reported within 72 hr after birth, we performed an adjusted linear regression analysis at 865,859 CpG sites to identify related methylation differences. We generated polyepigenetic scores using summary statistics for each exposure and assessed predictive ability using cross-validation and receiver operating characteristic curves. Specificity of methylation associations was evaluated by assessing overlap across exposure summary statistics and using logistic regression for methylation scores, adjusted for concurrent use. We identified methylation changes at 72, 21, and 1 CpG suggestively associated with prenatal exposure to opioids, cannabis, and polysubstance use, respectively (p p < 1e-8). Methylation scores were highly predictive and exposure-specific, with area under the curve accuracy of 91% for opioids, 90% for cannabis, and 93%-98% depending on polysubstance number. These CpGs provide biologic insights for reducing the impact of substance exposure, and these findings may serve as a biomarker of prenatal substance exposure for future studies and potential clinical utility.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42643049 · DOI · PMC13523970
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies [4]
- Research article Opioids for Chronic Noncancer Pain: A Systematic Review and Meta-analysis [5]
- Research article Association of Opioid Agonist Treatment With All-Cause Mortality and Specific Causes of Death Among People With Opioid Dependence: A Systematic Review and Meta-analysis [6]
- Research article Effectiveness and safety of non-steroidal anti-inflammatory drugs and opioid treatment for knee and hip osteoarthritis: network meta-analysis [7]
- Research article Analgesic impact of intra-operative opioids vs. opioid-free anaesthesia: a systematic review and meta-analysis [8]
- Research article Efficacy, Tolerability, and Dose-Dependent Effects of Opioid Analgesics for Low Back Pain: A Systematic Review and Meta-analysis [9]
References
- Gomez JL, Ventriglia EN, Frangos ZJ, Sulima A, Robertson MJ, Sacco MD, et al.. A µ-opioid receptor superagonist analgesic with minimal adverse effects. . 2026. PMID 41922775 · DOI · PMC13128446
- Kraglund F, Deleuran T, Storgaard MA, Sædder E, Jepsen P. Effects of Opioids, Benzodiazepines, Gabapentinoids, and Antidepressants on Fracture Risk in Alcohol-Related Cirrhosis. . 2026. PMID 42076874 · DOI · PMC13136785
- Garrison-Desany H, Howerton E, Hong X, Maher B, Pearson C, Zuckerman B, et al.. Association of prenatal exposure to opioids, cannabis, and polysubstance use with cord blood DNA methylation patterns in a multiancestry cohort. . 2026. PMID 42643049 · DOI · PMC13523970
- Sordo L, Barrio G, Bravo MJ, Indave BI, Degenhardt L, Wiessing L, et al.. Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies. BMJ. 2017. PMID 28446428 · DOI · PMC5421454
- Busse JW, Wang L, Kamaleldin M, Craigie S, Riva JJ, Montoya L, et al.. Opioids for Chronic Noncancer Pain: A Systematic Review and Meta-analysis. JAMA. 2018. PMID 30561481 · DOI · PMC6583638
- Santo T, Clark B, Hickman M, Grebely J, Campbell G, Sordo L, et al.. Association of Opioid Agonist Treatment With All-Cause Mortality and Specific Causes of Death Among People With Opioid Dependence: A Systematic Review and Meta-analysis. JAMA Psychiatry. 2021. PMID 34076676 · DOI · PMC8173472
- da Costa BR, Pereira TV, Saadat P, Rudnicki M, Iskander SM, Bodmer NS, et al.. Effectiveness and safety of non-steroidal anti-inflammatory drugs and opioid treatment for knee and hip osteoarthritis: network meta-analysis. BMJ. 2021. PMID 34642179 · DOI · PMC8506236
- Frauenknecht J, Kirkham KR, Jacot-Guillarmod A, Albrecht E. Analgesic impact of intra-operative opioids vs. opioid-free anaesthesia: a systematic review and meta-analysis. Anaesthesia. 2019. PMID 30802933 · DOI
- Abdel Shaheed C, Maher CG, Williams KA, Day R, McLachlan AJ. Efficacy, Tolerability, and Dose-Dependent Effects of Opioid Analgesics for Low Back Pain: A Systematic Review and Meta-analysis. JAMA Intern Med. 2016. PMID 27213267 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.