Related Experiment Video
Updated: Apr 15, 2026

Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Opioid-induced hyperalgesia after rapid titration with intravenous morphine: Switching and re-titration to
Sebastiano Mercadante1, Patrizia Ferrera2, Edoardo Arcuri3
1Anesthesia and Intensive Care Unit, Pain Relief and Palliative Care Unit, La Maddalena Cancer Center, Via S. Lorenzo 312, 90146, Palermo, Italy. terapiadeldolore@lamaddalenanet.it; 03sebelle@gmail.com.
Background:
Rapid titration with intravenous morphine (IV-MO) provides fast and efficient pain relief in cancer patients with severe-excruciating pain. However, some patients, after an initially favourable response, can develop an hyperexcitated state unrelieved or worsened by further dose increments.
Methods:
Eighty-one patients admitted on emergency basis titrated with IV-MO were assessed.
Results:
12 patients were unsuccessfully titrated with IV-MO. Switching to intravenous methadone (IV-ME) and titrating the doses proved to be successfully.
Conclusions:
In escalating opioid doses rapidly a recognition of the development of hyperalgesia should be suspected. Increasing doses of opioids may stimulate rather than inhibiting the central nervous system, with complex mechanisms already recognized in experimental studies. Switching to IV-ME and titrating the doses could be taken into consideration to break this vicious circle before pain conditions worsen irreversibly.
More Related Videos
Related Concept Videos
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Analgesia and Pain Management
Opioid Analgesics: Morphine and Other Natural Cogeners
Opioid Receptors: Overview
Drugs Affecting GI Tract Motility: Opioids as Antidiarrheal Agents
Opioids, widely used antidiarrheal agents, mitigate diarrhea by slowing down...
Desensitization and Tachyphylaxis

