Trial reportDrug and alcohol dependence2013
Abuse liability and reinforcing efficacy of oral tramadol in humans.
Trial report in Drug and alcohol dependence, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 35 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
35 citing papers in PubMed, 2 syntheses or guidelines pooled it, 131 citations in OpenAlex.
- Exploring the Confluence of Animal Medicine and its Implications for Human Health: A Systematic Literature Review.Current neuropharmacology · 2025Pooled it
- A Systematic Review of Laboratory Evidence for the Abuse Potential of Tramadol in Humans.Frontiers in psychiatry · 2019Pooled it
- The novel uncompetitive NMDA receptor antagonist esmethadone (REL-1017) has no meaningful abuse potential in recreational drug users.Translational psychiatry · 2023Trial
- Acute tramadol enhances brain activity associated with reward anticipation in the nucleus accumbens.Psychopharmacology · 2018Trial
- Intranasal buprenorphine alone and in combination with naloxone: Abuse liability and reinforcing efficacy in physically dependent opioid abusers.Drug and alcohol dependence · 2016Trial
- Efficacy of extended-release tramadol for treatment of prescription opioid withdrawal: a two-phase randomized controlled trial.Drug and alcohol dependence · 2013Trial
- Miotic and subject-rated effects of therapeutic doses of tapentadol, tramadol, and hydromorphone in occasional opioid users.Psychopharmacology · 2013Trial
- Article
- Nonpharmacological and pharmacological influences on opioid effects: A review of clinical research findings.The Journal of pharmacology and experimental therapeutics · 2025Review
- Tramadol-based multimodal pain protocols after arthroscopic rotator cuff repair are similarly effective as oxycodone-based protocols with fewer morphine milligram equivalents prescribed and lower risk of refills.Journal of orthopaedics · 2025Article
- Impact of Exercise on Tramadol-Conditioned Place Preference.Brain sciences · 2025Article
- Prevalence and factors associated with tramadol use among university students in Ghana: a cross-sectional survey.BMC psychiatry · 2024Article
- Human laboratory models of reward in substance use disorder.Pharmacology, biochemistry, and behavior · 2024Review
- Tramadol Provides Similar Pain Relief and a Better Side Effect Profile than Oxycodone (or Hydrocodone) Alone or in Combination With Tramadol After Anterior Cruciate Ligament Reconstruction or Arthroscopic Knee Debridement.Arthroscopy, sports medicine, and rehabilitation · 2023Article
- Zinc oxide calcium silicate composite attenuates acute tramadol toxicity in mice.BMC pharmacology & toxicology · 2023Article
- Comparative Histological Study on the Effect of Tramadol Abuse on the Testis of Juvenile and Adult Male Albino Mice.Anatomy & cell biology · 2022Article
- Increase of high-risk tramadol use and harmful consequences in France from 2013 to 2018: Evidence from the triangulation of addictovigilance data.British journal of clinical pharmacology · 2022Article
- Short-term mortality following tramadol poisonings in Denmark.Basic & clinical pharmacology & toxicology · 2022Article
- Comparison of Online Patient Reviews and National Pharmacovigilance Data for Tramadol-Related Adverse Events: Comparative Observational Study.JMIR public health and surveillance · 2022Observational
- Tramadol: a Potential Neurotoxic Agent Affecting Prefrontal Cortices in Adult Male Rats and PC-12 Cell Line.Neurotoxicity research · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 1 institution in 1 country.
Funding
Abstract
backgroundTramadol, a monoaminergic reuptake inhibitor, is hepatically metabolized to an opioid agonist (M1). This atypical analgesic is generally considered to have limited abuse liability. Recent reports of its abuse have increased in the U.S., leading to more stringent regulation in some states, but not nationally. The purpose of this study was to examine the relative abuse liability and reinforcing efficacy of tramadol in comparison to a high (oxycodone) and low efficacy (codeine) opioid agonist.
methodsNine healthy, non-dependent prescription opioid abusers (6 male and 3 female) participated in this within-subject, randomized, double blind, placebo-controlled study. Participants completed 14 paired sessions (7 sample and 7 self-administration). During each sample session, an oral dose of tramadol (200 and 400 mg), oxycodone (20 and 40 mg), codeine (100 and 200 mg) or placebo was administered, and a full array of abuse liability measures was collected. During self-administration sessions, volunteers were given the opportunity to work (via progressive ratio) for the sample dose or money.
resultsAll active doses were self-administered; placebo engendered no responding. The high doses of tramadol and oxycodone were readily self-administered (70%, 59% of available drug, respectively); lower doses and both codeine doses maintained intermediate levels of drug taking. All three drugs dose-dependently increased measures indicative of abuse liability, relative to placebo; however, the magnitude and time course of these and other pharmacodynamic effects varied qualitatively across drugs.
conclusionsThis study demonstrates that, like other mu opioids, higher doses of tramadol function as reinforcers in opioid abusers, providing new empirical data for regulatory evaluation.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.