Pharmacokinetic Study of Hydrocodone/APAP in Chronic Pain Patients

Study Overview
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Brief Summary
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Objective is to evaluate the pharmacokinetics profile of hydrocodone's metabolite hydromorphone in patients who are taking hydrocodone on a routine basis for more than 3 months for chronic pain and correlate hydromorphone levels to their hydrocodone usage.

Detailed Description
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Hydrocodone combinations are the most commonly prescribed pain medications in the United States. All the current available Hydrocodone formulations are short acting and have Acetaminophen/Ibuprofen in them. Chronic pain patients who take pain medications for extended time are overloaded with Acetaminophen and there is a very serious concern about liver failure from excessive concurrent alcohol use. Also all the current hydrocodone combinations available in the U.S. are short acting and provide pain relief for 3-6 hrs. Hydromorphone is a metabolite of Hydrocodone and plays a significant role in providing pain relief in these patients. Although there are no long acting or extended release hydrocodone formulations that are FDA approve at this time, there is once a day extended release Hydromorphone (ER) approved by FDA and is currently marketed under the name Exalgo ®. PK study of chronic hydrocodone/acetaminophen usage is important to determine equivalent potency with hydromorphone ER, so that clinicians can use a simple conversion formula to switch to hydromorphone ER. Although medical professionals use the Opiate conversion formula on a regular basis for Opioid rotation, there are no published studies showing the pharmacokinetic data in patients taking hydrocodone for chronic pain. Our goal is to use this PK data to guide clinicians with this data in using extended release hydromorphone for chronic pain management to provide predictable pain relief and minimize the acetaminophen usage.

Official Title
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Evaluating the Pharmacokinetic Profile of Hydromorphone in Chronic Pain Patients Taking Hydrocodone/APAP

Conditions
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Chronic Pain

Intervention / Treatment
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* Drug: Hydrocodone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Man or woman aged 18-75 Documented clinical diagnosis of chronic pain. Have been taking hydrocodone/APAP for their chronic non-cancer pain. Subjects currently on hydrocodone/APAP must be taking minimal daily dose of 15mg of Hydrocodone for at least 30 days. Subjects must have signed an informed consent document indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study. Exclusion Criteria: Subjects who are taking concomitant medications or Nutraceuticals that interfere with Hydrocodone metabolism as listed in Appendix 11 and/or as deemed clinically significant by a pharmacovigilance team that is contracted to monitor and advise. Health concerns that the study physician feels may confound study results. Individuals who are cognitively impaired or who are not able to give informed consent. Previous participation in a clinical research trial within 30 days prior to randomization. The subject has an ongoing abuse of illicit substances, alcohol, or actively smoking marijuana.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1<br>Blood will be drawn at 0, 1, 3, and 5 hours after taking one dose of hydrocodone/APAP. Urine will be taken at hour 0 and 3. | Drug: Hydrocodone<br>* Dose: Standard prescribed dose Frequency: Once Duration: Once<br>* Other names: Vicodin;|
| Experimental: Group 2<br>Blood will be drawn at 0, 2, 4, and 6 hours after one dose of hydrocodone/APAP. Urine will be taken at hour 0 and 4. | Drug: Hydrocodone<br>* Dose: Standard prescribed dose Frequency: Once Duration: Once<br>* Other names: Vicodin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak Plasma Concentration of Hydromorphone | Determine the plasma pharmacokinetic profile of hydromorphone in chronic pain subjects taking hydrocodone within a 6 hour time frame. Note: Sensitivity of the lab test used to determine plasma hydromorphone concentrations was not sufficient. Failure to meet the lowest level of detection, all subjects plasma hydromorphone concentrations were recorded as zero at all time points. | Up to 6 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of Plasma PK of Hydrocodone | Correlate the plasma pharmacokinetic profile of hydromorphone to their hydrocodone doses. | 1 Month | 
| Peak Urine Concentration of Hydromorphone | Analyze the urine concentration of hydromorphone | Up to 4 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pharmacokinetics, Hydromorphone, Hydrocodone, APAP