title: Intravenous Acetaminophen versus Morphine for Analgesia in Labor: A Randomized Trial.
abstract: ObjectiveTo compare the effectiveness of intravenous acetaminophen with that of morphine in reducing pain in the first stage of labor.MethodsAn open-label, randomized controlled trial of women ≥ 34 weeks gestation in the first stage of labor, assigned to either intravenous acetaminophen or morphine. The primary outcome was improved analgesia measured by difference of visual analog scale (VAS) score at 120 minutes from baseline. Secondary outcomes were request for rescue analgesia, maternal side effects, and fetal heart rate changes. Statistical analyses performed were chi-square, Student'st-test, and Kaplan-Meier survival analysis.ResultsOf 40 women randomized, 18 received acetaminophen (2 did not receive study drug), and 20 received morphine. Because of difficulties in recruitment, the sample size of 88 was not achieved. The primary outcome was similar between groups (p= 0.53). Within 120 minutes of initial treatment, more women receiving intravenous acetaminophen required rescue analgesia (acetaminophen: 52.9% vs. morphine: 17.6%,p< 0.01). Maternal and fetal side effects were similar between groups.ConclusionThere was no difference in VAS scores between groups. However, as half of women receiving intravenous acetaminophen required rescue analgesia within 120 minutes of treatment, intravenous acetaminophen may be less effective for analgesia in early labor compared with intravenous morphine.
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Nana-Ama E
authors.initials: NE
authors.lastname: Ankumah
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Marissa
authors.initials: M
authors.lastname: Tsao
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Maria
authors.initials: M
authors.lastname: Hutchinson
authors.affiliation: Center for Clinical Research and Evidence-Based Medicine, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pedroza
authors.affiliation: Department of Anesthesiology, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Jaideep
authors.initials: J
authors.lastname: Mehta
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Baha M
authors.initials: BM
authors.lastname: Sibai
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Suneet P
authors.initials: SP
authors.lastname: Chauhan
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Jerrie S
authors.initials: JS
authors.lastname: Refuerzo
mesh_terms: D000082:Acetaminophen / Q000627:therapeutic use*; D061605:Administration, Intravenous; D000328:Adult; D016362:Analgesia, Obstetrical / Q000379:methods*; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007747:Labor Stage, First; D007743:Labor, Obstetric; D009020:Morphine / Q000627:therapeutic use*; D010147:Pain Measurement; D011247:Pregnancy; D055815:Young Adult
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000082:Acetaminophen; D009020:Morphine