Epidural Methadone in Healthy Volunteers

• ClinicalTrials.gov Identifier: NCT03525509
• Recruitment Status: Completed
• First Posted: May 15, 2018
• Last Update Posted: September 18, 2019
• Sponsor: simon.haroutounian
• Information provided by (Responsible Party): simon.haroutounian, Washington University School of Medicine

Study Description

Brief Summary:

Epidurally administered opioid pain medications are important tools for postoperative pain control, but each agent has its own limitations. Methadone's properties suggest that it may provide a long duration of pain control with minimal side effects related to spread to the brain or absorption into the blood stream. In this study, the investigators aim to compare the relative pain relieving effects, markers of side effects, and concentrations in the blood of epidurally administered methadone as compared to another long-acting opioid which is commonly administered epidurally, morphine.

Condition or disease	Intervention/treatment	Phase
Pain, Acute	Drug: Methadone hydrochloride; Drug: Morphine Sulfate	Early Phase 1

Detailed Description:

Acute postoperative pain control remains a major challenge in healthcare, with a need to balance analgesic effectiveness, patient safety, and cost. Excellent analgesia is a universal clinical imperative, but our current approaches are often inadequate. Epidural opioids can be useful tools, but each carries its own strengths and limitations. Bolus morphine is long lasting but exhibits rostral spread in the cerebrospinal fluid, which raises risks of adverse effects, particularly late-onset respiratory depression. Lipophilic opioids such as fentanyl and sufentanil exhibit selective segmental analgesia but are of short duration due to systemic absorption. As such, they require continuous epidural administration via an indwelling epidural catheter and a pump (patient-controlled or continuous infusion), which has implications for nursing, pain management services, and hospital cost. Methadone's physico-chemical properties suggest that epidural methadone administration would be ideal in providing long-duration analgesia with fewer of the adverse effects seen with medications like morphine.

The aim of this study is to compare the effects of two medications given epidurally: morphine and methadone. We will do so using a randomized, double-blinded, crossover design study. During each of two study visits, participants will receive a single epidural bolus of either morphine or methadone. We will examine the ability of the medication to blunt pain from heat or pressure using quantitative sensory testing at both the dermatome of injection (leg) and a distant dermatome (face); in doing so, we will demonstrate relative segmental versus supraspinal or systemic opioid activity. Additionally, we will assess signs and symptoms of supraspinal opioid activity, which may predispose to adverse effects, and blood concentrations of each medication. Each of the aforementioned measurements will be conducted at multiple points over a 24 hour period. Following a washout period, patients will return for a second visit, at which time the protocol will be repeated using the other medication.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 13 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Intervention Model Description: Randomized, double-blinded, crossover design in healthy volunteers
• Masking: Triple (Participant, Investigator, Outcomes Assessor)
• Masking Description: At enrollment, each participant will be assigned a study number, which will match a previously prepared computer-generated list of randomization numbers to determine the interventions. Pharmacy staff who prepares blinded syringes of medications for administration will not be involved in medication administration, outcomes assessment, or statistical analysis. The participants and all other study personnel will be blinded to the treatment allocation.
• Primary Purpose: Treatment
• Official Title: Investigation of Pharmacokinetics and Pharmacodynamics of Epidural Methadone in Healthy Volunteers
• Actual Study Start Date: June 4, 2018
• Actual Primary Completion Date: August 28, 2019
• Actual Study Completion Date: August 30, 2019

Arms and Interventions

Arm	Intervention/treatment
Experimental: Epidural methadone; A single 4mg epidural bolus of methadone hydrochloride	Drug: Methadone hydrochloride; Epidural bolus of 4mg of preservative free methadone hydrochloride (4mL of 1mg/mL solution); Other Name: Epidural methadone
Active Comparator: Epidural morphine; A single 4mg epidural bolus of morphine sulfate	Drug: Morphine Sulfate; Epidural bolus of 4mg of preservative free morphine sulfate (4mL of 1mg/mL solution); Other Name: Epidural morphine

Outcome Measures

Primary Outcome Measures :

1. Selective segmental analgesia for heat pain - methadone [ Time Frame: 0 -12 hours after medication administration ]
   The analgesia provided by methadone at a given dermatome will be quantified as the area under the curve (AUC) of the heat pain tolerance threshold versus time curve. The selective segmental analgesic effect of methadone will be measured as difference of the AUC for L3 and V2.

Secondary Outcome Measures :

1. Selective segmental analgesia for heat pain - morphine [ Time Frame: 0 -12 hours after medication administration ]
   The analgesia provided by morphine at a given dermatome will be quantified as the area under the curve (AUC) of the heat pain tolerance threshold versus time curve. The selective segmental analgesic effect of morphine will be measured as difference of the AUC for L3 and V2.
2. Selective segmental analgesia for pressure pain - methadone [ Time Frame: 0 - 12 hours after medication administration ]
   The analgesia provided by methadone at a given dermatome will be quantified as the area under the curve (AUC) of the pressure pain threshold versus time curve. The selective segmental analgesic effect of methadone will be measured as difference of the AUC for L3 and V2.
3. Selective segmental analgesia for pressure pain - morphine [ Time Frame: 0 - 12 hours after medication administration ]
   The analgesia provided by morphine at a given dermatome will be quantified as the area under the curve (AUC) of the pressure pain threshold versus time curve. The selective segmental analgesic effect of morphine will be measured as difference of the AUC for L3 and V2.

Eligibility Criteria

• Ages Eligible for Study: 18 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

1. Age ≥18;
2. Body mass index between 18.5 and 30
3. Good general health with no remarkable medical conditions;
4. Able and willing to provide informed consent.

Exclusion Criteria:

1. Known history of hepatic, renal, and cardiac disease;
2. Known history of diabetes mellitus;
3. Chronic pain;
4. A skin or spine condition preventing safe epidural catheter placement;
5. Current pregnancy or lactation;
6. Known coagulopathy or ongoing anticoagulant use which contraindicates epidural catheter placement;
7. Known allergic reactions to opioids or local anesthetics;
8. History of current or prior substance use disorder or positive screen using the 4-question Simple Screening Instrument for Substance Abuse (SSI-SA).

Contacts and Locations

Locations

United States, Missouri

Washington University in St. Louis

Saint Louis, Missouri, United States, 63110

Sponsors and Collaborators

simon.haroutounian

Investigators

• Principal Investigator: Simon Haroutounian, PhD; Washington University in Saint Louis
• Principal Investigator: Yehuda Ginosar, MBBS; Washington University in Saint Louis

More Information

Publications:

Shir Y, Rosen G, Zeldin A, Davidson EM. Methadone is safe for treating hospitalized patients with severe pain. Can J Anaesth. 2001 Dec;48(11):1109-13.

Haroutiunian S, Kagan L, Yifrach-Damari I, Davidson E, Ratz Y, Hoffman A. Enhanced antinociceptive efficacy of epidural compared with i.v. methadone in a rat model of thermal nociception. Br J Anaesth. 2014 Jan;112(1):150-8. doi: 10.1093/bja/aet234. Epub 2013 Jul 10.

Bernards CM, Shen DD, Sterling ES, Adkins JE, Risler L, Phillips B, Ummenhofer W. Epidural, cerebrospinal fluid, and plasma pharmacokinetics of epidural opioids (part 1): differences among opioids. Anesthesiology. 2003 Aug;99(2):455-65.

Gedney JA, Liu EH. Side-effects of epidural infusions of opioid bupivacaine mixtures. Anaesthesia. 1998 Dec;53(12):1148-55.

• Responsible Party: simon.haroutounian, Assistant Professor of Anesthesiology, Chief of Clinical Research for Washington University Pain Center, Washington University School of Medicine
• ClinicalTrials.gov Identifier: NCT03525509
• Other Study ID Numbers: 201802099
• First Posted: May 15, 2018
• Last Update Posted: September 18, 2019
• Last Verified: September 2019

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: Undecided

• Studies a U.S. FDA-regulated Drug Product: Yes
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by simon.haroutounian, Washington University School of Medicine:

Methadone; Morphine; Quantitative sensory testing; Epidural

Additional relevant MeSH terms:

Acute Pain; Pain; Neurologic Manifestations; Morphine; Methadone; Analgesics, Opioid; Narcotics; Central Nervous System Depressants; Physiological Effects of Drugs; Analgesics; Sensory System Agents; Peripheral Nervous System Agents; Antitussive Agents; Respiratory System Agents