Effect of Mu-opioid Receptor Genetics on 3 Doses of Spinal Morphine for Postoperative Analgesia After Cesarean Section

• Sponsor: Columbia University (Other)
• Overall Status: Completed
• CT.gov ID: NCT01465191
• Collaborator: (none)
• Enrollment: 169
• Locations: 2
• Arms: 3
• Duration (Months): 30
• Patients Per Site: 84.5
• Patients Per Site Per Month: 2.8

Study Details

Study Description

Brief Summary

HYPOTHESIS: The response to a given dose of morphine given via a spinal anesthetic for cesarean section will be affected by the genetics of the woman's mu-opioid receptor

Most women undergoing elective cesarean section (CS) receive spinal anesthesia, and most receive a dose of preservative free morphine with the spinal anesthetic. Spinally-administered morphine provides 16-24 hours of high quality pain relief. The dose administered is usually 75-200 micrograms, but surprisingly few dose-response studies exist.

The mu-opioid receptor (OPRM1 gene)is the site of action of endogenous opioid peptides and opioid analgesic drugs like morphine. There is a common genetic variant of this receptor at the 40th amino acid of the protein, with asparagine and asparate being present in different people. The less common variant (aspartate), present in 25-30% of the overall American population (higher in Asian populations, lower in Blacks) at codon 40 that has been shown in many studies to affect opioid analgesia.

This will be a randomized, blinded study of 3 doses of spinal morphine (50, 100, 150 micrograms) given to women undergoing elective cesarean section at term pregnancy. 300 women will be studied (100 per dose). Blood will be obtained for genotyping of OPRM1 and other genes that may affect pain and analgesic responses. The primary outcome will be the amount of intravenous morphine patients self-administer in the 24 hours postsurgery.

The primary outcome (use of intravenous morphine) will be analyzed by dose, and within each dose group by genotype of OPRM1. Secondary outcomes will include pain scores every 6 hours, satisfaction with analgesia, side effects (itching, nausea/vomiting) by dose and genotype.

It is anticipated that there will be an interim data analysis at 150 evaluable subjects for assessment of the dose response to morphine in the overall population; then a final analysis at 300 subjects for the genetic effect assessment.

Condition or Disease	Intervention/Treatment	Phase
Postoperative Pain	Drug: Morphine	Phase 4

Study Design

• Study Type: Interventional
• Actual Enrollment: 169 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: Effect of OPRM1 Genotype on the Dose Response to Spinal Morphine for Post-Cesarean Analgesia
• Study Start Date: Nov 1, 2011
• Actual Primary Completion Date: May 1, 2014
• Actual Study Completion Date: May 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
Experimental: 50 micrograms (mcg) spinal morphine Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section	Drug: Morphine; Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section
Experimental: 100 micrograms spinal morphine Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section	Drug: Morphine; Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section
Experimental: 150 micrograms spinal morphine Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section	Drug: Morphine; Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section

Outcome Measures

Primary Outcome Measures

1. Milligrams of Intravenous Morphine Used by Participant in First 24 Hours Postoperatively [24 hours]

   IV morphine use in milligrams, by participant-controlled analgesia will be assessed every 6 hours for 24 hours postoperatively.

Secondary Outcome Measures

1. Visual Analog Scale (VAS) Pain at 6 Hours [6 hours post-operatively]

   Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.

2. Visual Analog Scale (VAS) Pain at 12 Hours [12 hours post-operatively]

   Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.

3. Visual Analog Scale (VAS) Pain at 18 Hours [18 hours post-operatively]

   Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.

4. Visual Analog Scale (VAS) Pain at 24 Hours [24 hours post-operatively]

   Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.

5. Visual Analog Scale- Nausea/Vomiting at 6 Hours [6 hours post-operatively]

   Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).

6. Visual Analog Scale- Nausea/Vomiting at 12 Hours [12 hours post-operatively]

   Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).

7. Visual Analog Scale- Nausea/Vomiting at 18 Hours [18 hours post-operatively]

   Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).

8. Visual Analog Scale- Nausea/Vomiting at 24 Hours [24 hours post-operatively]

   Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).

9. Visual Analog Scale Pruritus (Itching) at 6 Hours [6 hours post-operatively]

   Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).

10. Visual Analog Scale Pruritus (Itching) at 12 Hours [12 hours post-operatively]

    Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).

11. Visual Analog Scale Pruritus (Itching) at 18 Hours [18 hours post-operatively]

    Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).

12. Visual Analog Scale Pruritus (Itching) at 24 Hours [24 hours post-operatively]

    Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).

13. Visual Analog Patient Satisfaction With Analgesia at 24 Hours [24 hours postoperatively]

    Visual analog patient satisfaction scale measures satisfaction with analgesia on a 100mm scale. Participants make a mark on the scale with one end labeled "Completely Dissatisfied" (0mm) and the other labeled "Completely Satisfied" (100mm).

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 45 Years
• Sexes Eligible for Study: Female
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• healthy women undergoing elective cesarean

Exclusion Criteria:

• cardiovascular disease

• analgesic medications

• complications of pregnancy

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	George Washington University Medical Center	Washington	District of Columbia	United States	20037
2	Columbia University Medical Center	New York	New York	United States	10032

Sponsors and Collaborators

• Columbia University

Investigators

• Principal Investigator: Richard M Smiley, MD, PhD, Columbia University

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Richard M. Smiley, Professr of Clinical Anesthesiology, Columbia University
• ClinicalTrials.gov Identifier: NCT01465191
• Other Study ID Numbers: AAAI2804
• First Posted: Nov 4, 2011
• Last Update Posted: Dec 10, 2020
• Last Verified: Nov 1, 2020

• Keywords provided by Richard M. Smiley, Professr of Clinical Anesthesiology, Columbia University: cesarean; postoperative; morphine; genetics; opioid
• Additional relevant MeSH terms: Pain, Postoperative; Morphine

Study Results

Participant Flow

Arm/Group Title	50 Micrograms Spinal Morphine	100 mcg Spinal Morphine	150 mcg Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Period Title: Overall Study
STARTED	56	63	50
COMPLETED	47	54	43
NOT COMPLETED	9	9	7

Baseline Characteristics

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine	Total
Arm/Group Description	these subjects will receive 50 mcg spinal morphine	these subjects will receive 100 mcg spinal morphine	these subjects will receive 150 mcg spinal morphine	Total of all reporting groups
Overall Participants	47	54	43	144
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%	0 0%
Between 18 and 65 years	47 100%	54 100%	43 100%	144 100%
>=65 years	0 0%	0 0%	0 0%	0 0%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	33 (6)	33 (5)	33 (6)	33 (4)
Sex: Female, Male (Count of Participants)
Female	47 100%	54 100%	43 100%	144 100%
Male	0 0%	0 0%	0 0%	0 0%
Region of Enrollment (participants) [Number]
United States	47 100%	54 100%	43 100%	144 100%

Outcome Measures

1. Primary Outcome

Title	Milligrams of Intravenous Morphine Used by Participant in First 24 Hours Postoperatively
Description	IV morphine use in milligrams, by participant-controlled analgesia will be assessed every 6 hours for 24 hours postoperatively.
Time Frame	24 hours

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [Milligrams]	18	14	15

2. Secondary Outcome

Title	Visual Analog Scale (VAS) Pain at 6 Hours
Description	Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.
Time Frame	6 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Rest	20	25	15
Movement	43	43	30

3. Secondary Outcome

Title	Visual Analog Scale (VAS) Pain at 12 Hours
Description	Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.
Time Frame	12 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Rest	20	15	10
Movement	30	35	30

4. Secondary Outcome

Title	Visual Analog Scale (VAS) Pain at 18 Hours
Description	Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.
Time Frame	18 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Rest	17	11	5
Movement	32	30	26

5. Secondary Outcome

Title	Visual Analog Scale (VAS) Pain at 24 Hours
Description	Visual analog pain scale measures pain on a 100 millimeter (mm) scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst pain imaginable" (100mm). Pain measured at rest and with movement.
Time Frame	24 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Rest	24	21	18
Movement	43	41	41

6. Secondary Outcome

Title	Visual Analog Scale- Nausea/Vomiting at 6 Hours
Description	Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).
Time Frame	6 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	0	7	0

7. Secondary Outcome

Title	Visual Analog Scale- Nausea/Vomiting at 12 Hours
Description	Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).
Time Frame	12 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	0	0	0

8. Secondary Outcome

Title	Visual Analog Scale- Nausea/Vomiting at 18 Hours
Description	Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).
Time Frame	18 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	0	0	0

9. Secondary Outcome

Title	Visual Analog Scale- Nausea/Vomiting at 24 Hours
Description	Visual analog nausea/vomiting scale measures nausea and vomiting on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Nausea/Vomiting Imaginable" (100mm).
Time Frame	24 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	0	0	0

10. Secondary Outcome

Title	Visual Analog Scale Pruritus (Itching) at 6 Hours
Description	Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).
Time Frame	6 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	21	37	39

11. Secondary Outcome

Title	Visual Analog Scale Pruritus (Itching) at 12 Hours
Description	Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).
Time Frame	12 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	10	23	25

12. Secondary Outcome

Title	Visual Analog Scale Pruritus (Itching) at 18 Hours
Description	Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).
Time Frame	18 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	9	13	5

13. Secondary Outcome

Title	Visual Analog Scale Pruritus (Itching) at 24 Hours
Description	Visual analog pruritus scale measures itching on a 100mm scale. Participants make a mark on the scale with one end labeled "None" (0mm) and the other labeled "Worst Itching Imaginable" (100mm).
Time Frame	24 hours post-operatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	7	12	6

14. Secondary Outcome

Title	Visual Analog Patient Satisfaction With Analgesia at 24 Hours
Description	Visual analog patient satisfaction scale measures satisfaction with analgesia on a 100mm scale. Participants make a mark on the scale with one end labeled "Completely Dissatisfied" (0mm) and the other labeled "Completely Satisfied" (100mm).
Time Frame	24 hours postoperatively

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	50 Micrograms Spinal Morphine	100 Micrograms Spinal Morphine	150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.	Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed.
Measure Participants	47	54	43
Mean (Inter-Quartile Range) [mm]	85	83	84

Adverse Events

Time Frame	24 hours
Arm/Group Title	50 Micrograms Spinal Morphine		100 Micrograms Spinal Morphine		150 Micrograms Spinal Morphine
Arm/Group Description	Subjects will receive 50 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed and analyzed with 47 in this group		Subjects will receive 100 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed and analyzed with 54 in this group		Subjects will receive 150 mcg morphine in their spinal anesthetic for cesarean section Morphine: Morphine will be given via spinal injection at doses of 50, 100, 150 micrograms as part of a spinal anesthetic for cesarean section After interim analysis, the genetics part of the analysis was dropped and the study completed and analyzed with 43 in this group
All Cause Mortality
	50 Micrograms Spinal Morphine		100 Micrograms Spinal Morphine		150 Micrograms Spinal Morphine
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/47 (0%)		0/54 (0%)		0/43 (0%)
Serious Adverse Events
	50 Micrograms Spinal Morphine		100 Micrograms Spinal Morphine		150 Micrograms Spinal Morphine
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/47 (0%)		0/54 (0%)		0/43 (0%)
Other (Not Including Serious) Adverse Events
	50 Micrograms Spinal Morphine		100 Micrograms Spinal Morphine		150 Micrograms Spinal Morphine
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/47 (0%)		0/54 (0%)		0/43 (0%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.