Related Experiment Video
Updated: Jun 25, 2026
07:23
Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Codeine and clinical impairment in samples in which morphine is not detected
Liliana Bachs1, Svetlana Skurtveit, Jørg Mørland
1National Institute of Forensic Toxicology, PO Box 495 Sentrum, 0105, Oslo, Norway. lilibachs@yahoo.no
European Journal of Clinical Pharmacology
|April 17, 2003
Summary
Codeine may cause impairment independent of its metabolite morphine, as shown by a clinical test for drunkenness. Higher codeine blood concentrations correlated with increased impairment, suggesting a direct effect on the central nervous system.
Area of Science:
- Pharmacology
- Forensic Toxicology
- Neuroscience
Background:
- Codeine is metabolized to morphine by CYP2D6, with analgesic effects potentially attributed to morphine.
- Sedative effects of codeine may occur independently of morphine formation.
- Investigating codeine's direct CNS effects is crucial for impaired driving assessments.
Purpose of the Study:
- To evaluate the impact of codeine, without concurrent morphine, on a clinical test for drunkenness (CTD).
- To determine if codeine itself contributes to impairment in suspected drugged driving cases.
Main Methods:
- Analysis of blood samples from suspected drugged drivers with detected codeine but no morphine.
- Comparison of codeine blood concentrations with CTD results.
- Statistical analysis adjusting for age, gender, and chronic use.
Main Results:
- A statistically significant difference in mean codeine blood concentrations was observed between impaired and unimpaired groups.
- Higher codeine concentrations were associated with increased odds of impairment (OR=6 for medium-high, OR=19 for high).
- Impairment judgments on the CTD were dose-dependently linked to codeine levels.
Conclusions:
- Codeine demonstrates a dose-dependent effect on the central nervous system, potentially causing impairment.
- These findings suggest that codeine's impairing effects can be independent of its conversion to morphine.
- This supports the hypothesis that some codeine effects are not mediated by morphine.
Related Concept Videos
01:02Prescription, Nonprescription and Orphan Drugs
Prescription drugs require a prescription from a medical practitioner and can only be obtained from a pharmacy. They have many applications, including treating pain, anxiety, and hypertension.
The misuse and addiction to prescription drugs is a growing problem that can affect people of all age groups, specifically teenagers. This can happen when prescription medications are used in ways not intended by the prescriber, such as taking someone else's prescription or using medication for...
The misuse and addiction to prescription drugs is a growing problem that can affect people of all age groups, specifically teenagers. This can happen when prescription medications are used in ways not intended by the prescriber, such as taking someone else's prescription or using medication for...
01:15Drug Abuse and Addiction: Pharmacological Phenomena
Drug dependence, abuse, and addiction are complex phenomena that can precipitate various abnormal states. Physical dependence refers to a state of pharmacological adaptation to a drug. This adaptation often results in tolerance—a reduced response to the drug after repeated administrations. When the drug use is abruptly stopped, withdrawal symptoms occur due to the body's need to readjust from the pharmacologically induced imbalance. However, tolerance and withdrawal symptoms do not necessarily...
01:22Opioid Receptors: Overview
Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2, D-Pen5]-enkephalin or DPDPE for...
01:25Analgesia and Pain Management
Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...
01:20Opioid Analgesics: Morphine and Other Natural Cogeners
Opioids are a class of drugs that mimic endogenous opioid peptides and act on opioid receptors, and help in pain relief. These compounds are classified as natural, synthetic, or semi-synthetic. Natural opioids, like morphine, codeine, and thebaine, are derived from the opium poppy plant (Papaver somniferum or Papaver album) and are termed opiates. Synthetic opioids are artificial, while semi-synthetic opioids combine natural and synthetic compounds. Morphine, a prototypical opioid, possesses a...
01:15Opioid Analgesics: Synthetic and Semisynthetic Opioids
Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...