II. Indications

III. Contraindications (See specific medications)

  1. Intrauterine Fetal Demise or lethal fetal anomaly
  2. Nonreassuring Fetal Status
    1. Fetal Bradycardia <100
    2. Fetal Tachycardia >180
  3. Severe Preeclampsia or Eclampsia
  4. Maternal bleeding with hemodynamic instability
    1. Maternal Systolic Blood Pressure <90 mmHg
  5. Maternal cardiopulmonary symptoms (e.g. Shortness of Breath, Chest Pain)
  6. Chorioamnionitis

IV. Preparations: Preferred Tocolytics

  1. General Indications
    1. Stops labor for 24-48 hours
    2. Allows maternal transport and Corticosteroid doses
  2. Magnesium Sulfate
    1. Load: 6 grams bolus IV over 20 min (Very high dose!, some protocols use 4 g load)
    2. Maintenance: 2 grams/hour IV infusion (max: 3 g/h)
    3. Must follow protocols for patient safety
    4. Tocolytic and neuroprotective (with decreased risk of Cerebral Palsy in deliveries before 32 weeks)
      1. Doyle (2009) Obstet Gynecol 113(6): 1327-33 [PubMed]
    5. Does not prevent preterm birth
      1. Gyetvai (1999) Obstet Gynecol 94:869-77 [PubMed]
  3. Indomethacin (Indocin)
    1. Load: 50-100 mg orally or rectally
    2. Maintenance: 25-50 mg orally every 4-6 hours for up to 48 hours
    3. Avoid use >48 hours (risk of oligohydramnios, premature closure ductus arteriosus)
    4. Not recommended after 32 weeks due to ductus arteriosus constriction
  4. Nifedipine (Procardia)
    1. Load: 30 mg orally
    2. Maintenance: 10-20 mg every 4-6 hours (max: 180 mg/day)
    3. Higher risk of maternal adverse effects when combined with Magnesium Sulfate

V. Preparations: Other Tocolytics

  1. Terbutaline
    1. Load: 0.25 mg SQ every 20-30 min for up to 4 doses
    2. Maintenance: 0.25 mg every 3-4 hours until Uterus quiet for 24 hours
    3. Effective at temporarily stopping contractions
      1. Results in shortest hospital triage stays
      2. Guinn (1997) Am J Obstet Gynecol 177:814-87 [PubMed]
    4. Oral Terbutaline is not effective in Preterm Labor
      1. Lewis (1996) Am J Obstet Gynecol 175:834-7 [PubMed]
  2. Ritodrine
    1. Not available in the United States as of 2013
    2. Curiously, was the only FDA approved Preterm Labor Tocolytic
    3. Not shown to be more effective than Placebo
    4. (1992) N Engl J Med 327:308-12 [PubMed]

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Related Studies

Ontology: Tocolysis (C0040348)

Definition (MSH) Any drug treatment modality designed to inhibit UTERINE CONTRACTION. It is used in pregnant women to arrest PREMATURE LABOR.
Concepts Therapeutic or Preventive Procedure (T061)
MSH D015145
SnomedCT 103747003
LNC LA20008-1
English Therapies, Tocolytic, Therapy, Tocolytic, Tocolyses, Tocolysis, Tocolytic Therapies, Tocolytic Therapy, Tocolytic Treatment, Tocolytic Treatments, Treatment, Tocolytic, Treatments, Tocolytic, THER TOCOLYTIC, TOCOLYTIC THER, tocolytic therapy, tocolyse, tocolysis, tocolytic treatment, Inhibition of uterine contractions, Tocolysis (procedure)
Swedish Tokolys
Japanese ジンツウヨクセイ, 子宮収縮抑制, 陣痛抑制, 子宮収縮抑制療法, 出産消散
Czech tokolýza, Tokolýza
Finnish Tokolyysi
Russian RODOVOI DEIATEL'NOSTI SNIZHENIE, TOKOLIZ, TOKOLITICHESKAIA TERAPIIA, РОДОВОЙ ДЕЯТЕЛЬНОСТИ СНИЖЕНИЕ, ТОКОЛИЗ, ТОКОЛИТИЧЕСКАЯ ТЕРАПИЯ
French Thérapie tocolytique, Tocolyse, Traitement tocolytique
Italian Trattamento tocolitico, Terapia tocolitica, Tocolisi
Polish Leczenie tokolityczne, Tokoliza
Hungarian Tocolysis
Norwegian Tokolyse, Tokolytisk behandling, Tokolytisk terapi
Spanish inhibición de las contracciones uterinas, tocólisis (procedimiento), tocólisis, Tocolisis, Tocólisis, Terapia Tocolítica
Portuguese Tocolise, Terapia Tocolítica, Tocólise
Dutch tocolyse, Therapie, tocolytische, Tocolyse
German Tokolyse, Tokolytische Therapie

Ontology: Tocolytic Agents (C0040349)

Definition (CSP) class of drugs which inhibit premature labor.
Definition (MSH) Drugs that prevent preterm labor and immature birth by suppressing uterine contractions (TOCOLYSIS). Agents used to delay premature uterine activity include magnesium sulfate, beta-mimetics, oxytocin antagonists, calcium channel inhibitors, and adrenergic beta-receptor agonists. The use of intravenous alcohol as a tocolytic is now obsolete.
Concepts Pharmacologic Substance (T121)
MSH D015149
SnomedCT 262212007
English Agents, Tocolytic, Tocolytic Agents, Tocolytics, tocolytic agent, tocolytics, tocolytic, drugs tocolytic, tocolytic agents, Tocolytic drug, Tocolytic drug (product), Tocolytic drug (substance)
German Mittel zur Hemmung der Wehentätigkeit, Wehenhemmende Mittel, Wehenhemmer, Tokolysemittel, Tokolytika
French Médicaments tocolytiques, Agents tocolytiques, Tocolytiques
Swedish Tokolytika
Czech tokolytika
Finnish Tokolyytit
Italian Tocolitici, Agenti tocolitici
Russian TOKOLITICHESKIE SREDSTVA, RODOVUIU DEIATEL'NOST' SNIZHAIUSHCHIE SREDSTVA, РОДОВУЮ ДЕЯТЕЛЬНОСТЬ СНИЖАЮЩИЕ СРЕДСТВА, ТОКОЛИТИЧЕСКИЕ СРЕДСТВА
Croatian TOKOLITICI
Polish Leki przeciw skurczom macicy, Środki hamujące poród, Środki hamujące czynność skurczową macicy, Leki tokolityczne
Japanese 陣痛抑制剤, 子宮収縮抑制剤, 子宮収縮抑制薬, 陣痛抑制薬
Spanish Tocolíticos, Efecto Tocolítico, Agentes Tocolíticos, Fármacos Tocolíticos, fármaco tocolítico (producto), fármaco tocolítico
Portuguese Efeito Tocolítico, Fármacos Tocolíticos, Agentes Tocolíticos, Tocolíticos