IV Acetaminophen vs IV Morphine for Pain Control in Pregnant Women

A Randomized, Controlled Trial of IV Acetaminophen Versus IV Morphine to Manage Pain in Pregnancy: Can Opioid Use be Reduced in Pregnant Women?

Purpose: To determine if IV acetaminophen can 1) decrease pain in pregnancy women, 2)reduce the amount of opioid use in pregnant women who encounter pain, 3) reduce maternal and fetal adverse effects compared to opioids.

Design: This is a comparative effective trial that is a randomized, controlled trial of IV acetaminophen vs. IV morphine in pregnant women.

Procedures: Women meeting inclusion/exclusion criteria will be randomized to IV acetaminophen or IV morphine. The IV acetaminophen group will get up to four standard doses of IV acetaminophen during their stay at the hospital. The second group will get up to six standard doses of morphine. Subjects will complete a pain scale after medication administration and will be asked about any side effects.

Study Overview

• Status: Terminated
• Conditions: Pain Management in Pregnant Women
• Intervention / Treatment: Drug: IV Acetaminophen; Drug: IV Morphine

Detailed Description

Rationale for this clinical trial The goal of analgesia in pregnancy is to reduce pain while minimizing both maternal and fetal adverse effects. Current opioids used in pregnancy provide minimal pain relief and are associated with adverse effects. IV acetaminophen has been shown to significantly improve pain control following cesarean section and in the first stage of labor. Moreover, IV acetaminophen reduces the need and consumption of opioids following surgery. If IV acetaminophen can be as effective in controlling pain associated with maternal medical conditions and uterine contractions with labor, then the use of parenteral opioids in pregnant women and its exposure to the fetus could be reduced. This could provide new opportunities in the medical management of pain in pregnancy. Thus we propose a comparative effectiveness trial of IV acetaminophen compared to IV morphine.

Hypothesis:

We hypothesize that IV acetaminophen is as effective as IV morphine in reducing pain in pregnant women. In doing so, IV acetaminophen can reduce the amount of narcotics needed in women with pain.

Objectives:

To determine if IV acetaminophen can:

1. Decrease pain in pregnant women
2. Reduce the amount of opioid use in pregnant women who encounter pain
3. Reduce maternal and fetal adverse effects compared to opioids

Study Design:

For this comparative effective trial, we propose a randomized, controlled trial of IV acetaminophen vs. IV morphine in pregnant women. Prior studies have confirmed that IV acetaminophen is effective in controlling pain compared to placebo.[14,20] Thus, administering just a placebo for pain control is not justified at this time.

We will include 3 different groups of pregnant populations who encounter pain for different reasons.

Group 1: Pregnant women with uterine contractions, but not in labor Group 2: Pregnant women with uterine contractions in the first stage of labor Group 3: Pregnant women with a medical condition associated with pain.

• Study Type: Interventional
• Enrollment (Actual): 163
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77030
      • Memorial Hermann Hospital, Texas Medical Center
    • Houston, Texas, United States, 77026
      • Lyndon B Johnson Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 58 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion criteria:

Group 1. We will include pregnant women greater than 24 weeks of pregnancy who present with uterine contractions, but are not in labor and who are warranting treatment with intravenous medication for pain control as part of their routine treatment. This will be defined as the presence of uterine contractions documented on the tocodynamometer. However, the cervix remains less than 2 cm dilated and has not changed after 1 hour after re-examining her cervix.[23]

Group 2. We will include pregnant women greater than 34 weeks of pregnancy who present with uterine contractions and are in the first stage of labor and who are warranting treatment with intravenous medication for pain control as part of their routine treatment. This will be defined as the presence of uterine contractions documented on the tocodynamometer and cervical dilation greater than 2 cm, but less than 6 cm. [23]

Group 3. We will include pregnant women greater than 16 weeks of pregnancy who present with pain due to a maternal medical condition including sickle cell crisis, pyelonephritis, pancreatitis, cholecystitis, nephrolithiasis or headache and who are warranting treatment with intravenous medication for pain control as part of their routine treatment.

Exclusion criteria:

We will exclude women less than 18 years of age, less than 16 weeks gestation, with weight less than 50 kg, and contraindications to acetaminophen including reported elevated liver function tests, hepatic injury, hepatic disorder, active liver disease, alcoholism, chronic malnutrition, known coagulopathy, hemorrhage, creatinine > 1.0, or known allergy or hypersensitivity to acetaminophen. We will also exclude women who have received any opioids within the last 24 hours.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: IV Acetaminophen; IV acetaminophen for pain control	Drug: IV Acetaminophen; IV Acetaminophen
Active Comparator: IV morphine; IV morphine for pain control	Drug: IV Morphine; IV Morphine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Pain Intensity as Assessed by a Visual Analogue Scale (VAS)	The visual analogue scale (VAS) ranges from 0mm to 140mm. The subject will be asked to mark with a pen on the scale to rate their pain. Negative differences in scores indicated a pain score worse than baseline and positive differences indicated an improved pain score from baseline.	baseline, 120 minutes after administration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Relief Based on a 5 Point Verbal Scale		24 hrs
Number of Participants Who Received Rescue Medications		24 hours after administration
Quantity of Rescue Medication Over 24 Hours		24 hours after administration
Total Amount of Study Drug Administered		24 hours after administration
Patient's Global Satisfaction at 24 Hours	This will be patient reported.	24hrs
Number of Participants With Maternal Side Effects	Maternal side effects include nausea, vomiting, headache, pruritus, insomnia, and drowsiness.	1 hour after administration
Number of Participants With Fetal Heart Rate Changes	Changes in fetal heart rate tracing include acceleration, decelerations, and variability.	1 hour after administration

Collaborators and Investigators

• Sponsor: The University of Texas Health Science Center, Houston
• Investigators: Principal Investigator: Jerrie S Refuerzo, MD, The University of Texas Health Science Center, Houston

Publications and helpful links

General Publications

• Ankumah NE, Tsao M, Hutchinson M, Pedroza C, Mehta J, Sibai BM, Chauhan SP, Blackwell SC, Refuerzo JS. Intravenous Acetaminophen versus Morphine for Analgesia in Labor: A Randomized Trial. Am J Perinatol. 2017 Jan;34(1):38-43. doi: 10.1055/s-0036-1584143. Epub 2016 May 16.

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (Actual): April 27, 2019
• Study Completion (Actual): April 27, 2019

Study Registration Dates

• First Submitted: October 14, 2014
• First Submitted That Met QC Criteria: October 14, 2014
• First Posted (Estimate): October 17, 2014

Study Record Updates

• Last Update Posted (Actual): January 22, 2021
• Last Update Submitted That Met QC Criteria: December 31, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Antipyretics; Analgesics, Opioid; Narcotics; Acetaminophen; Morphine
• Other Study ID Numbers: HSC-MS-13-0763