Opioid medications are commonly used for pain relief. When given over time, physical dependence can occur. This results in unpleasant side effects--such as agitation and nausea--if opioid medications are suddenly stopped. However, we do not know how withdrawal affects the brain. We know that a medication named Ondansetron can help ease or prevent symptoms associated with opioid withdrawal. Through imaging of the brain by fMRI, we hope to see how opioid withdrawal, with and without the administration of ondansetron, affects brain activity.
During the study, each participant attended three separate lab-based acute opioid withdrawal sessions. The first session was undertaken in a mock MRI scanner and was designed to determine if participants could tolerate withdrawal in the scanning environment. Participants who were able to successfully and safely tolerate opioid withdrawal while in the scanner were approved to continue with the following study sessions. Participants were then pretreated intravenously (IV) with either 0.9% normal saline placebo or 8mg ondansetron. Later, participants in all sessions received IV naloxone (10mg/70kg) to precipitate opioid withdrawal. Participants were assigned to ondansetron or placebo pretreatment conditions in a randomized, double-blinded, and counter-balanced order. Objective Opioid Withdrawal Scale (OOWS) and Subjective Opioid Withdrawal Scale (SOWS) were assessed throughout the study to quantify withdrawal. Study timeline progressed as follows: T=-165, 8mg ondansetron or placebo infusion, T=-135, Morphine infusion (10mg/70kg), T=-41 preparation for MRI, T=-21, start MRI, T=-13, baseline OOWS/SOWS, T=-9, start of fMRI, T=0 Naloxone induced withdrawal, T=5, OOWS, T=15, OOWS, T=20, Retrospective OOWS.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
15
In this cross-over study, the blinded patient will receive saline placebo in one session and ondansetron in the other. The order is decided with a randomization table. If ondansetron is randomly chosen, an 8mg IV Bolus will be given at the start of the study for 30 minutes by the unblinded investigator.
Stanford University School of Medicine
Stanford, California, United States
Brain Regions With Increases or Decreases in Amplitude of Low Frequency Fluctuations (ALFF) Associated With Ondansetron Administration
Changes are reporting using Spearman's correlation coefficient, using within-subject factors of time (pre-naloxone, post-naloxone) and pre-treatment (placebo, ondansetron). Changes in Objective Opioid Withdrawal Scale (OOWS) and Subjective Opioid Withdrawal Scale (SOWS) with correlation coefficient \>0.45 are reported. The OOWS consists of 13 observable physical symptoms assessed over a 5-minute observation period and scored as present (score of 1) or absent (score of 0). The total OOWS scores is determined by summing the scores of the 13 items. OOWS scores can range from 0 to 13; lower scores correspond to fewer symptoms. SOWS consists of 16 physical and emotional symptoms rated by the participant on a scale from 0 (not at all) to 4 (extremely), to indicate the extent to which the symptom describes how they are feeling at the time. The total SOWS score is determined by summing the scores of the 16 items. Scores range from 0 to 64; lower scores correspond to fewer symptoms.
Time frame: 36 minutes
Objective Opioid Withdrawal Scale Score 5 Minutes Following Ondansetron or Placebo Administration
The OOWS consists of 13 observable physical symptoms that are assessed over a five-minute observation period and scored as present (score of 1) or absent (score of 0). The total OOWS scores is determined by summing the scores of the 13 items. OOWS scores can range from a low of 0 to a high of 13. A score of 0 would suggest that no objective signs of withdrawal were observed while a score of 13 would suggest that every observable sign of withdrawal was observed.
Time frame: 5 Minutes Following Ondansetron or Placebo Administration
Objective Opioid Withdrawal Scale Score 15 Minutes Following Ondansetron or Placebo Administration
The OOWS consists of 13 observable physical symptoms that are assessed over a five-minute observation period and scored as present (score of 1) or absent (score of 0). The total OOWS scores is determined by summing the scores of the 13 items. OOWS scores can range from a low of 0 to a high of 13. A score of 0 would suggest that no objective signs of withdrawal were observed while a score of 13 would suggest that every observable sign of withdrawal was observed.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: 15 Minutes Following Ondansetron or Placebo Administration
Subjective Opioid Withdrawal Scale (SOWS) Score 20 Minutes Following Ondansetron or Placebo Administration
The SOWS consists of 16 physical and emotional symptoms that are rated by the participant on a scale from 0 (not at all) to 4 (extremely), to indicate the extent to which the symptom describes how they are feeling at the time. The total SOWS score is determined by summing the scores of the 16 items. Scores range from a low of 0 to a high of 64. A score of 0 would suggest that the individual is experiencing no symptoms of withdrawal while a score of 64 would suggest that the individual is experiencing all 16 symptoms of withdrawal to the fullest extent possible.
Time frame: 20 minutes following Ondansetron or Placebo administration