Related Experiment Video
Updated: Aug 23, 2026

Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Optimum dose of epidural morphine for postsurgical analgesia
1Department of Anesthesiology, Ehime University School of Medicine, Ehime-ken, Japan.
Abstract:
To determine the optimum dose of epidural morphine for postoperative pain control, 0.5-4.0 mg of morphine was administered to 198 patients who had undergone operations on lower abdomen or lower extremities under continuous epidural anesthesia. Analgesic effect of morphine and incidence of nausea or vomiting were studied using linear discriminant analysis. As explanatory variables, age and dose of morphine were statistically significant in discriminating analgesic effect of morphine. Among indices for physique of patients, height was the most useful for predicting the analgesic effect. The dose which made the discriminant function zero corresponded to the minimum effective dose (MED) of morphine and it was expressed as follows; MED (mg.meter(-1)) = -0.0107 x age + 1.85. Predicting the incidence of nausea or vomiting in relation to the dose of morphine did not reach a level of statistical significance.
Related Concept Videos
Local Anesthetics: Clinical Application as Epidural Anesthesia
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Analgesia and Pain Management
Opioid Analgesics: Morphine and Other Natural Cogeners
Local Anesthetics: Clinical Application as Spinal Anesthesia
Parenteral Anesthetics: Overview