Treatment of pain following major surgery
Morphine is an opioid analgesic that is relatively selective for the mu-receptor, although it can interact with other opiate receptors at higher doses. While its exact mechanism of analgesic action is unknown, morphine appears to produce analgesia by interacting with opioid receptors in the CNS, perhaps mimicking enkephalins and endorphins. This extended-release formulation consists of lipid-based particles containing discrete water-filled chambers dispersed through the lipid matrix, which contain the active drug. The small amount of lipid in the formulation is cleared rapidly in the body as the particles deliver morphine into the epidural space, providing pain relief for up to 48 hours following surgery.
The efficacy of morphine extended-release liposome epidural injection was demonstrated in four controlled clinical trials involving 876 patients undergoing surgical procedures such as hip arthroplasty, prostatectomy, colon resection, and cesarean section. Efficacy in these studies was assessed by a reduction in pain intensity using Visual Analog Scores (VAS) and/or a reduction in rescue pain medication over 48 hours. Study results showed that morphine extended-release liposome epidural injection significantly reduced pain intensity and/or cumulative rescue pain medication usage, compared with placebo or standard epidural morphine injection.
|Volume of distribution||1-4 L/kg|
|Metabolism||Hepatic glucuronidation, sulfation,and demethylation. Glucuronideproducts include morphine-3-glucuronide (50%) and morphine-6-glucuronide (5%-15%)|
|Excretion||Urine (2%-12%)Feces (7%-10%)|
|Half-life||Epidural morphine extended-releaseliposome, 3.8-32.9 hours (5- to 25-mg doses); standard epidural morphine, 2.2 hours (5-mg dose)|
Morphine extended-release liposome injection is an opioid analgesic that has demonstrated efficacy in the treatment of pain following major surgery for up to 48 hours after a single epidural injection. After major surgery, the level of pain is usually very high for the first 24-48 hours, but the intensity gradually subsides, allowing for oral analgesic control. This extended-release epidural morphine formulation does not require an indwelling or IV catheter for continuous infusion or patient-controlled analgesia. A catheter can fall out, interfere with patient mobility, or increase the risk of infection. For patients who require anticoagulants prior to or during surgery, this new long-acting formulation will reduce the risk of bleeding into the spinal column that can be associated with epidural catheters. DepoDur was previously referred to as DepoMorphine.
Published September 2004. Content based on medical literature and product information available at that time.