View clinical trials related to Opioid Tolerance.
Filter by:Effect of N-methyl D-aspartate (NMDA) receptor antagonist Dextromethorphan on Opiods analgesia and tolerance in Pediatric Intensive Care Unit Patients
When narcotic pain medicine, like fentanyl or morphine, is given to adults and children for several days, they often develop a tolerance to the medicine. This means they may need higher doses over time to get the same amount of pain control. When it is time to stop the medicine, the dose has to be decreased slowly so that the patient does not have withdrawal symptoms. Naloxone is a medicine that at high doses can reverse the effects of narcotics. At very small doses it may help prevent tolerance and lessen the severity of withdrawal symptoms. This could mean less narcotic pain medicine is needed over fewer days. The purpose of this research study is to see if giving naloxone to neonates who require narcotic infusions is safe and effective. Safety will be measured by the incidence of side effects. Efficacy will be measured by monitoring for changes in pain and sedation scores and need for more pain medicine.
Opioids, such as fentanyl, are commonly used in PICU patients to provide comfort and pain control. Opioid tolerance, the need to increase the dose of medication to achieve the same effect,is seen in PICU children who require opioid infusions. Animals and human studies have shown that activation of the N-methyl-D-aspartate (NMDA) receptor is involved in the development of opioid tolerance and that deactivation of this receptor can slow the development of tolerance. Ketamine, an NMDA receptor antagonists, turns off the NMDA receptor. Ketamine is used to provide sedation and anesthesia in children. Its use in inhibiting the development of opioid tolerance has not been tested in children. We aim to determine ketamine's effectiveness in the treatment of tolerance in PICU patients who require fentanyl infusions to treat pain and discomfort . Some physicians have reported using ketamine doses of 0.04mg/kg/hr to 0.5mg/kg/hr to inhibit opioid tolerance. We propose to study the sedative effect, and the metabolism of, three doses of ketamine, 0.1mg/kg/hr, 0.3mg/kg/hr, and 0.5mg/kg/hr. Patients admitted to the PICU, requiring a breathing machine and fentanyl infusion for discomfort or pain control will be enrolled. Patients' age three to eighteen years will be enrolled. Patients will receive a ketamine infusion once their COMFORT scores indicate an adequate sedation/comfort level on their current sedation regimen. The COMFORT score is a validated scale that measures distress in PICU patients. The COMFORT score will be continued for the twelve hours the patient receives the ketamine to test whether the ketamine adds to the level of sedation. Blood samples during and following the ketamine infusion will be taken to determine how ketamine and norketamine (one of ketamine's metabolites) are used in the body. To determine the effect of ketamine on tolerance it must be a ketamine dose that does not cause additional sedation. The goal of this study is to define a non-sedating dose of ketamine and define how it is used by the body. A non-sedating ketamine dose could be added to current sedation regimens allowing us to monitor the development of tolerance without the confusion of added sedation. The data obtained in this study will be used to design a study to further investigate the effect of ketamine on opioid tolerance.
Recently there has been an increased awareness in the need for adequate sedation and pain control for Pediatric Intensive Care Unit (ICU) patients. Fentanyl is an opioid commonly used in Pediatric ICU patients to decrease pain and increase sedation. Although opioids (e.g. morphine and fentanyl) provide excellent pain relief, they have many side effects including dependence, tolerance and withdrawal. These side effects lead to increased doses in order to maintain pain control and/or sedation. There have been a few adult studies pointing to some possible treatments. For example, giving low dose naloxone along with opioids. Adult studies show that this combination not only decreases the frequency of opioid side effects, but also improves pain control and prevents the development of tolerance. We propose that children who receive low dose naloxone infusions along with fentanyl infusions will demonstrate: 1) decreased total daily doses of Fentanyl, 2) decreased frequency of withdrawal and 3) increased pain and sedation control. In this randomized, blinded prospective trial we will enroll 168 Pediatric ICU patients. Patients will receive either low dose naloxone or placebo simultaneously with their fentanyl infusion. Pain and sedation will be assessed using the Modified Motor Activity Assessment Scale (MMAAS). The fentanyl infusion will be increased to provide adequate pain control and/or sedation. Naloxone infusion will not be adjusted. Approximately 48 hours prior to removal from the ventilator, patients will have their fentanyl infusions decreased while being monitored for withdrawal. Patients showing signs of withdrawal will receive methadone, an opioid taken by mouth. Once off fentanyl, naloxone will be stopped. Patients will continue to be monitored for withdrawal for 4 days or until ICU discharge. If this study works, patients who receive low dose naloxone along with opioid infusions will have less tolerance and dependence and demonstrate less withdrawal. This may cause shorter Intensive Care Unit stays.