Ignite Creation Date:
2024-05-05 @ 5:13 PM
Last Modification Date:
2024-10-26 @ 9:29 AM
Study NCT ID:
NCT00418015
Status:
COMPLETED
Last Update Posted:
2014-04-14
First Post:
2006-12-31
Brief Title:
Mu-Opioid Receptor Genetic Polymorphism and Intrathecal Analgesia
Sponsor:
Northwestern University
Organization:
Northwestern University
Study Overview
Official Title:
Mu-Opioid Receptor Genetic Polymorphism and the Duration of Intrathecal Fentanyl Labor Analgesia Mu-Opioid Receptor Genetic Polymorphism and the Efficacy of Postoperative Intrathecal Morphine Analgesia
Status:
COMPLETED
Status Verified Date:
2014-03
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Pharmacogenetics has allowed clinicians to identify associations between an individuals genetic profile and hisher response to drugs The A118G c188AGis a single nucleotide polymorphism SNP of the mu-opioid receptor OPRM1 The mutated protein N40D appears to increase the binding affinity and potency of beta-endorphin approximately 3-fold Individuals carrying the variant receptor gene A118G may show differences in some of the functions mediated by beta-endorphin action at the altered OPRM1 Combined spinal-epidural CSE analgesia is a commonly utilized technique for labor analgesia Analgesia is initiated with the intrathecal administration of a lipid-soluble opioid eg fentanyl sometimes combined with a local anesthetic The mean SD duration of analgesia after intrathecal fentanyl 25 microgram was 89 43 min The ED50 of intrathecal fentanyl for labor analgesia varies between 14 microgram to 182 microgram The wide variability in the duration of analgesia as was well the differences in ED50 may result from differences known to affect labor pain eg ethnicity parity stage of labor Another possible explanation for the differences in opioid requirements and duration as well as incidence of side effects such as itching and nauseavomiting is that opioid responsiveness is determined by genetic variability of the µ-opioid receptor The ED50 for intrathecal fentanyl labor analgesia was significantly lower for parturients carrying the A118G variant of the mu-opioid receptor compared to parturients with the A118 wild type receptor The purpose of this study is to determine whether polymorphism at nucleotide 118 of OPRM1 influences the duration of intrathecal opioid fentanyl labor analgesia and intrathecal opioid morphine postoperative analgesia
Detailed Description:
Study 1 intrathecal fentanyl The primary outcome variable is duration of intrathecal fentanyl analgesia A two-sided log rank test with an overall sample size of 152 subjects wild type OPRM1 106 variant OPRM1 46 achieves 80 power at α 005 to detect a difference of 02 between 05 and 03 the proportion of subjects with continuing intrathecal fentanyl analgesia after 70 min This assumes that 70 of subjects will have the wild-type MUOR1 phenotype and 30 the variant phenotype To account for anticipated subject dropout 175 subjects will be enrolled in the study
Study 2 intrathecal morphine The primary outcome variable is amount of rescue analgesia morphine equivalents necessary for 24 h after the intrathecal morphine injection An overall sample size of 71 subjects wild type OPRM1 50 variant OPRM1 21 achieves 81 power to detect a difference of 15 mg morphine equivalents between the null hypothesis that both group means are 40 mg morphine equivalents and the alternative hypothesis that the mean of one group is 25 mg morphine equivalents The estimated group standard deviations are 20 mg morphine equivalents with alpha 005 using a two-side Mann-Whitney test assuming that the actual distribution is uniform This assumes that 70 of subjects will have the wild-type OPRM1 phenotype and 30 the variant phenotype To account for anticipated subject dropout 90 subjects will be enrolled in the study
Protocol specific methods
Study 1 Eligible parturients admitted to the Labor and Delivery Unit of Prentice Womens Hospital will be approached for study participation immediately after the routine preanesthetic evaluation This occurs shortly after admission to the Labor and Delivery Unit Women who agree to participate will give written informed consent at this time
Venous blood will be obtained for genetic analysis of the 118 position of the µ-opioid receptor gene shortly after the subject consents to study participation either through an intravenous catheter placed for routine intravenous access for labor and delivery or through a fresh venipuncture A total of 10 mL blood will be collected into two 5 mL EDTA tubes The tubes will be batched coded and stored in a 40C refrigerator until they will be send 1xmonth to the laboratory of Dr J L Blouin care of Dr Landau at the Hopitaux Universitaires de Geneve Genetic analysis will be performed as described below When the subject first requests analgesia her cervix will be examined this is routine procedure prior to initiating analgesia If the cervix is dilated between 2 and 5 cm the parturient will be included in the study Visual analogue score VAS for pain 100 mm line where 0 mm no pain and 100 mm worst possible pain will be determined immediately before initiation of analgesia Combined spinal-epidural analgesia will be initiated in the sitting position per routine with intrathecal fentanyl 25 microgram An epidural catheter will be sited No drug will be injected through the epidural catheter until the parturient requests analgesia again The parturient will be placed in the lateral position after the epidural catheter is secured A VAS will be determined 10 min after the intrathecal injection
The primary outcome variable is duration of intrathecal fentanyl analgesiaAt the time the parturient requests additional analgesia the cervix will be examined A VAS will be determined In addition the parturient will be asked about the presence of pruritus since the initiation of analgesia none mild moderate severe nausea none mild moderate or severe and vomiting yes no An epidural test dose will be administered lidocaine 15 with epinephrine 1200000 Assuming a negative test dose bupivacaine 0125 will be injected incrementally to a T10 sensory level Epidural analgesia will be maintained with patient controlled epidural analgesia PCEA bupivacaine 00625 with fentanyl 195 micro gramsmL background infusion 15 mLh PCEA bolus 5 mL lockout 10 min maximum 30 mLh as per routine
The study ends after the parturient delivers and the epidural infusion is discontinued At this time the subject will be asked about her satisfaction with labor analgesia 100 mm scale 0 mm not satisfied at all 100 mm very satisfied
The following data will be collected maternal age height weight race self-described cervical dilation at initiation of analgesia time and cervical dilation at 2nd request for analgesia maximum oxytocin dose time to complete cervical dilation 10 cm time to delivery mode of delivery neonatal weight Apgar scores and umbilical blood gas values obtained as part of routine care total dose of epidural bupivacaine and other local anesthetics total dose of epidural fentanyl number of PCEA boluses and number of manual boluses by the anesthesiologist
Cases will be excluded from data analysis if CSE analgesia is not performed if there is no analgesia VAS 10 mm 10 minutes after the intrathecal injection failure of CSE technique if cervical dilation is 8 cm within 60 minutes of intrathecal injection or if the patient has a cesarean delivery These cases will be reported
Study 2 Eligible women admitted to the Labor and Delivery Unit of Prentice Womens Hospital for planned Cesarean delivery will be approached for study participation immediately after the routine preanesthetic evaluation This occurs shortly after admission to the Labor and Delivery Unit Women who agree to participate will give written informed consent at this time
Venous blood will be obtained for genetic analysis of the 118 position of the µ-opioid receptor gene shortly after the subject consents to study participation either through an intravenous catheter placed for routine intravenous access for labor and delivery or through a fresh venipuncture A total of 10 mL blood will be collected into two 5 mL EDTA tubes The tubes will be batched coded and stored in a 4oC refrigerator until they are sent 1timemonth to the laboratory of Dr J L Blouin care of Dr Landau at the Hospitaux Universitaires de Geneve Genetic analysis will be performed as described below Routine aspiration prophylaxis will be administered intravenous ranitidine and metoclopramide and oral antacid Spinal anesthesia will be initiated in the sitting position in the routine manner with bupivacaine 12 mg 16 mL 075 hyperbaric bupivacaine fentanyl 15 µg and morphine 150 micrograms Subjects will be placed in the supine left uterine displacement position immediately after the intrathecal injection The level of cephalad sensory blockade will be determined 30 min after the intrathecal injection using von Frye hairs Subjects with a sensory level below T6 or those that require intraoperative systemic opioid supplementation will be excluded from further study participation
In the PACU and for 24 hours after surgery patients will receive ibuprofen 600 mg po q6h as per standard protocol Patients may request rescue analgesia if they are experiencing discomfort Rescue medication will consist of hydrocodone 10 mg plus acetaminophen 325 mg per os An additional dose of hydrocodone 10 mg plus acetaminophen 325 mg will be provided after 1 hour if the pain is not relieved These are routine oral analgesic medications for postoperative Cesarean delivery analgesia Standard orders will be written for monitoring sedation and respiratory rate and treatment of side effects nausea vomiting pruritus and respiratory depression
The primary outcome variable is amount of rescue morphine equivalent analgesia required for the 24 hours after the intrathecal morphine injection18 The time of first rescue analgesia request will be noted and the VAS will be determined at the time of request for rescue analgesia In addition the parturient will be asked to provide a VAS for pain at 4 8 12 18 and 24 hours after the intrathecal injection The presence of pruritus none mild moderate severe nausea none mild moderate or severe and vomiting yes no will be determined at 4 and 24 h after the intrathecal injection
The study ends 24 h after the intrathecal injection At this time the subject will be asked about her satisfaction with postoperative analgesia 100 mm scale 0 mm not satisfied at all 100 mm very satisfied Further analgesia will not be dictated by study protocol
The following data will be collected maternal age height weight race self-described requirement for supplemental intraoperative sedation neonatal weight intra- or postoperative treatment for pruritus nausea or vomiting In addition to the time to first request for supplemental oral analgesia the following will be recorded supplement analgesia dose requirements number of acetaminophenhydrocodone tablets at 4 8 12 18 and 24 h after the intrathecal injection
DNA collection Peripheral blood will be collected in 2 5ml EDTA tubes total 10ml DNA will be prepared by non-phenolic methods using Puregene Blood Extraction Kit Gentra Minneapolis MN and tested for molecular weight on gel electrophoresis and purity quality by optical densitometry measure ratio 260280 nm
SNP genotyping For identification of allelic distribution of the A118G SNP 20-60 ng of DNA from individuals will be first amplified by PCR on thermocycler apparatuses equipped with a 96 well-microtiter plate block using primers designed in the vicinity of the SNPs The SNP will be then genotyped in amplified products by minisequencing Pyrosequencing
Pyrosequencing PCR using cDNA specific primers spanning an intron in genomic DNA in which the forward primer is labeled with 5 biotin is performed under standard conditions and the product is analyzed by the Pyrosequencing method Briefly an internal primer is designed two nucleotides before the mutation site so that the two mRNA populations could be assayed by quantifying the relative amounts of each allele present in the PCR product DNA from normal and affected subjects are used as controls
PCR products are immobilized with Dynabeads Dynal Oslo Norway by a 15 min 65 oC incubation in a buffer containing 10mM Tris-HCl 2M NaCl 1mM EDTA and 01 Tween 20 PCR products are then removed from solution using magnetic separation denatured with NaOH 05 M and washed with 200mM Tris-Acetate 50mM MgAc2 The remaining single stranded DNA is then hybridized with the internal sequencing primer by heating the mix to 80oC and slowly cooling it to room temperature Next enzyme and substrate mixes are automatically added to each well and the reactions proceed at 28oC by the sequential addition of single nucleotides at a predetermined order Luciferase peak heights are proportional to the number of nucleotide incorporations which has been shown to be very quantitative 5 error rate in a number of experimental settings
Coded DNA samples will be stored in Dr Blouins laboratory No further sequencing will be done unless subjects signed the consent form for further future studies
Study 2 intrathecal morphine The primary outcome variable is amount of rescue analgesia morphine equivalents necessary for 24 h after the intrathecal morphine injection An overall sample size of 71 subjects wild type OPRM1 50 variant OPRM1 21 achieves 81 power to detect a difference of 15 mg morphine equivalents between the null hypothesis that both group means are 40 mg morphine equivalents and the alternative hypothesis that the mean of one group is 25 mg morphine equivalents The estimated group standard deviations are 20 mg morphine equivalents with alpha 005 using a two-side Mann-Whitney test assuming that the actual distribution is uniform This assumes that 70 of subjects will have the wild-type OPRM1 phenotype and 30 the variant phenotype To account for anticipated subject dropout 90 subjects will be enrolled in the study
Protocol specific methods
Study 1 Eligible parturients admitted to the Labor and Delivery Unit of Prentice Womens Hospital will be approached for study participation immediately after the routine preanesthetic evaluation This occurs shortly after admission to the Labor and Delivery Unit Women who agree to participate will give written informed consent at this time
Venous blood will be obtained for genetic analysis of the 118 position of the µ-opioid receptor gene shortly after the subject consents to study participation either through an intravenous catheter placed for routine intravenous access for labor and delivery or through a fresh venipuncture A total of 10 mL blood will be collected into two 5 mL EDTA tubes The tubes will be batched coded and stored in a 40C refrigerator until they will be send 1xmonth to the laboratory of Dr J L Blouin care of Dr Landau at the Hopitaux Universitaires de Geneve Genetic analysis will be performed as described below When the subject first requests analgesia her cervix will be examined this is routine procedure prior to initiating analgesia If the cervix is dilated between 2 and 5 cm the parturient will be included in the study Visual analogue score VAS for pain 100 mm line where 0 mm no pain and 100 mm worst possible pain will be determined immediately before initiation of analgesia Combined spinal-epidural analgesia will be initiated in the sitting position per routine with intrathecal fentanyl 25 microgram An epidural catheter will be sited No drug will be injected through the epidural catheter until the parturient requests analgesia again The parturient will be placed in the lateral position after the epidural catheter is secured A VAS will be determined 10 min after the intrathecal injection
The primary outcome variable is duration of intrathecal fentanyl analgesiaAt the time the parturient requests additional analgesia the cervix will be examined A VAS will be determined In addition the parturient will be asked about the presence of pruritus since the initiation of analgesia none mild moderate severe nausea none mild moderate or severe and vomiting yes no An epidural test dose will be administered lidocaine 15 with epinephrine 1200000 Assuming a negative test dose bupivacaine 0125 will be injected incrementally to a T10 sensory level Epidural analgesia will be maintained with patient controlled epidural analgesia PCEA bupivacaine 00625 with fentanyl 195 micro gramsmL background infusion 15 mLh PCEA bolus 5 mL lockout 10 min maximum 30 mLh as per routine
The study ends after the parturient delivers and the epidural infusion is discontinued At this time the subject will be asked about her satisfaction with labor analgesia 100 mm scale 0 mm not satisfied at all 100 mm very satisfied
The following data will be collected maternal age height weight race self-described cervical dilation at initiation of analgesia time and cervical dilation at 2nd request for analgesia maximum oxytocin dose time to complete cervical dilation 10 cm time to delivery mode of delivery neonatal weight Apgar scores and umbilical blood gas values obtained as part of routine care total dose of epidural bupivacaine and other local anesthetics total dose of epidural fentanyl number of PCEA boluses and number of manual boluses by the anesthesiologist
Cases will be excluded from data analysis if CSE analgesia is not performed if there is no analgesia VAS 10 mm 10 minutes after the intrathecal injection failure of CSE technique if cervical dilation is 8 cm within 60 minutes of intrathecal injection or if the patient has a cesarean delivery These cases will be reported
Study 2 Eligible women admitted to the Labor and Delivery Unit of Prentice Womens Hospital for planned Cesarean delivery will be approached for study participation immediately after the routine preanesthetic evaluation This occurs shortly after admission to the Labor and Delivery Unit Women who agree to participate will give written informed consent at this time
Venous blood will be obtained for genetic analysis of the 118 position of the µ-opioid receptor gene shortly after the subject consents to study participation either through an intravenous catheter placed for routine intravenous access for labor and delivery or through a fresh venipuncture A total of 10 mL blood will be collected into two 5 mL EDTA tubes The tubes will be batched coded and stored in a 4oC refrigerator until they are sent 1timemonth to the laboratory of Dr J L Blouin care of Dr Landau at the Hospitaux Universitaires de Geneve Genetic analysis will be performed as described below Routine aspiration prophylaxis will be administered intravenous ranitidine and metoclopramide and oral antacid Spinal anesthesia will be initiated in the sitting position in the routine manner with bupivacaine 12 mg 16 mL 075 hyperbaric bupivacaine fentanyl 15 µg and morphine 150 micrograms Subjects will be placed in the supine left uterine displacement position immediately after the intrathecal injection The level of cephalad sensory blockade will be determined 30 min after the intrathecal injection using von Frye hairs Subjects with a sensory level below T6 or those that require intraoperative systemic opioid supplementation will be excluded from further study participation
In the PACU and for 24 hours after surgery patients will receive ibuprofen 600 mg po q6h as per standard protocol Patients may request rescue analgesia if they are experiencing discomfort Rescue medication will consist of hydrocodone 10 mg plus acetaminophen 325 mg per os An additional dose of hydrocodone 10 mg plus acetaminophen 325 mg will be provided after 1 hour if the pain is not relieved These are routine oral analgesic medications for postoperative Cesarean delivery analgesia Standard orders will be written for monitoring sedation and respiratory rate and treatment of side effects nausea vomiting pruritus and respiratory depression
The primary outcome variable is amount of rescue morphine equivalent analgesia required for the 24 hours after the intrathecal morphine injection18 The time of first rescue analgesia request will be noted and the VAS will be determined at the time of request for rescue analgesia In addition the parturient will be asked to provide a VAS for pain at 4 8 12 18 and 24 hours after the intrathecal injection The presence of pruritus none mild moderate severe nausea none mild moderate or severe and vomiting yes no will be determined at 4 and 24 h after the intrathecal injection
The study ends 24 h after the intrathecal injection At this time the subject will be asked about her satisfaction with postoperative analgesia 100 mm scale 0 mm not satisfied at all 100 mm very satisfied Further analgesia will not be dictated by study protocol
The following data will be collected maternal age height weight race self-described requirement for supplemental intraoperative sedation neonatal weight intra- or postoperative treatment for pruritus nausea or vomiting In addition to the time to first request for supplemental oral analgesia the following will be recorded supplement analgesia dose requirements number of acetaminophenhydrocodone tablets at 4 8 12 18 and 24 h after the intrathecal injection
DNA collection Peripheral blood will be collected in 2 5ml EDTA tubes total 10ml DNA will be prepared by non-phenolic methods using Puregene Blood Extraction Kit Gentra Minneapolis MN and tested for molecular weight on gel electrophoresis and purity quality by optical densitometry measure ratio 260280 nm
SNP genotyping For identification of allelic distribution of the A118G SNP 20-60 ng of DNA from individuals will be first amplified by PCR on thermocycler apparatuses equipped with a 96 well-microtiter plate block using primers designed in the vicinity of the SNPs The SNP will be then genotyped in amplified products by minisequencing Pyrosequencing
Pyrosequencing PCR using cDNA specific primers spanning an intron in genomic DNA in which the forward primer is labeled with 5 biotin is performed under standard conditions and the product is analyzed by the Pyrosequencing method Briefly an internal primer is designed two nucleotides before the mutation site so that the two mRNA populations could be assayed by quantifying the relative amounts of each allele present in the PCR product DNA from normal and affected subjects are used as controls
PCR products are immobilized with Dynabeads Dynal Oslo Norway by a 15 min 65 oC incubation in a buffer containing 10mM Tris-HCl 2M NaCl 1mM EDTA and 01 Tween 20 PCR products are then removed from solution using magnetic separation denatured with NaOH 05 M and washed with 200mM Tris-Acetate 50mM MgAc2 The remaining single stranded DNA is then hybridized with the internal sequencing primer by heating the mix to 80oC and slowly cooling it to room temperature Next enzyme and substrate mixes are automatically added to each well and the reactions proceed at 28oC by the sequential addition of single nucleotides at a predetermined order Luciferase peak heights are proportional to the number of nucleotide incorporations which has been shown to be very quantitative 5 error rate in a number of experimental settings
Coded DNA samples will be stored in Dr Blouins laboratory No further sequencing will be done unless subjects signed the consent form for further future studies
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None