When looking up the drugs used that stimulate uterine contractions, Oxytocics, I also noticed that this post needs to include the drugs that are used to reverse the effect of those drugs, a group called Tocolytics.  As with the two previous posts in this series, I have listed the FDA Pregnancy category, included links to the complete drug profiles, and then pulled out the warning, adverse reaction, and contraindication sections for you to read right here and right now.

To be clear – we are not anti-care provider or anti-drug.  We are grateful for modern medicine that saves lives in circumstances when Mother Nature needs help.  It exists for a reason, and we are thankful for the opportunity to meet all the Healthy Moms and Healthy Babies when we hold a class reunion.

We are passionate about helping families have their Best Possible Birth.  By that we mean the path that leads each individual family to a Healthy Mom, Healthy Baby outcome.  We want families to have a toolbox full of tips and techniques that help them manage the ebb and flow of labor.  We want them to be comfortable with the path of a normal, low-risk labor.  We want them to have true informed consent by having an open line of communication with their care providers.

To that end, I am sharing the information below in the interest of furthering our goal that all our students have true informed consent: knowing all the benefits and risks of a drug or procedure.  It is very rare for anyone to read the drug information insert that comes in all drug packages.  To save you time and squinting, we are already researched Epidural Drugs and Induction Drugs.  To conclude the “Warning Label” Series, here are the drugs used for Augmentation and to counteract the strong contractions they have the potential to stimulate.

PITOCIN: Pregnancy Category X
http://www.drugs.com/pro/pitocin.html
Contraindications:
“Antepartum [before delivery] use of Pitocin is contraindicated in any of the following circumstances:
Where there is significant cephalopelvic disproportion;
In unfavorable fetal positions or presentations, such as transverse lies, which are undeliverable without conversion prior to delivery;
In obstetrical emergencies where the benefit-to-risk ratio for either the fetus or the mother favors surgical intervention;
In fetal distress where delivery is not imminent;
Where adequate uterine activity fails to achieve satisfactory progress;
Where the uterus is already hyperactive or hypertonic;
In cases where vaginal delivery is contraindicated, such as invasive cervical carcinoma, active herpes genitalis, total placenta previa, vasa previa, and cord presentation or prolapse of the cord;
In patients with hypersensitivity to the drug.”

Precautions
“When properly administered, oxytocin should stimulate uterine contractions comparable to those seen in normal labor. Overstimulation of the uterus by improper administration can be hazardous to both mother and fetus. Even with proper administration and adequate supervision, hypertonic contractions can occur in patients whose uteri are hypersensitive to oxytocin. This fact must be considered by the physician in exercising his judgment regarding patient selection.”

“Except in unusual circumstances, oxytocin should not be administered in the following conditions: fetal distress, hydramnios, partial placenta previa, prematurity, borderline cephalopelvic disproportion, and any condition in which there is a predisposition for uterine rupture, such as previous major surgery on the cervix or uterus including cesarean section, overdistention of the uterus, grand multiparity, or past history of uterine sepsis or of traumatic delivery. Because of the variability of the combinations of factors which may be present in the conditions listed above, the definition of "unusual circumstances" must be left to the judgment of the physician. The decision can be made only by carefully weighing the potential benefits which oxytocin can provide in a given case against rare but definite potential for the drug to produce hypertonicity or tetanic spasm.
Maternal deaths due to hypertensive episodes, subarachnoid hemorrhage, rupture of the uterus, and fetal deaths due to various causes have been reported associated with the use of parenteral oxytocic drugs for induction of labor or for augmentation in the first and second stages of labor.”

“Oxytocin has been shown to have an intrinsic antidiuretic effect, acting to increase water reabsorption from the glomerular filtrate. Consideration should, therefore, be given to the possibility of water intoxication, particularly when oxytocin is administered continuously by infusion and the patient is receiving fluids by mouth.
When oxytocin is used for induction or reinforcement of already existent labor, patients should be carefully selected. Pelvic adequacy must be considered and maternal and fetal conditions evaluated before use of the drug.”

Adverse Reactions
“The following adverse reactions have been reported in the mother:

“The possibility of increased blood loss and afibrinogenemia should be kept in mind when administering the drug.”

“Severe water intoxication with convulsions and coma has occurred, associated with a slow oxytocin infusion over a 24-hour period. Maternal death due to oxytocin-induced water intoxication has been reported.”

“The following adverse reactions have been reported in the fetus or neonate:

Due to induced uterine motility:

Related drug SYNTOCINON® - most of the information is identical
http://www.drugs.com/pro/syntocinon.html

ERGOTRATE (ERGONOVINE) – Pregnancy: Should not be administered prior to delivery or delivery of the placenta
http://www.drugs.com/mmx/ergotrate.html
Pregnancy—
“Use of ergonovine is contraindicated during pregnancy…Tetanic contractions may result in decreased uterine blood flow and fetal distress.”

Labor and delivery—
“High doses of ergonovine administered prior to delivery may cause uterine tetany and problems in the infant (hypoxia, intracranial hemorrhage) {03}. Ergonovine should not be administered prior to delivery of the placenta…Administration prior to delivery of the placenta may cause captivation of the placenta…or missed diagnosis of a second infant, due to excessive uterine contraction.”

Breast-feeding
“Problems in humans have not been documented. However, ergot alkaloids are excreted in breast milk…Although inhibition of lactation has not been reported for ergonovine, other ergot alkaloids inhibit lactation. Also, studies have shown that ergonovine interferes with the secretion of prolactin (to a lesser degree than bromocriptine) in the immediate postpartum period…This could result in delayed or diminished lactation with prolonged use.”

“Ergot alkaloids have the potential to cause chronic ergot poisoning in the infant if used in higher-than-recommended doses or if used for a longer period of time than is generally recommended.”

Pediatrics
"Elimination of ergonovine may be prolonged in newborns...Neonates inadvertently administered ergonovine in overdose amounts have developed respiratory depression, cyanosis, seizures, decreased urine output, and severe peripheral vasoconstriction."

METHERGINE: Category C
http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=94c9b1cf-ae12-45f3-8fcb-708a922cbc10
INDICATIONS AND USAGE
“For routine management after delivery of the placenta; postpartum atony and hemorrhage; subinvolution. Under full obstetric supervision, it may be given in the second stage of labor following delivery of the anterior shoulder.”

CONTRAINDICATIONS
"Hypertension; toxemia; pregnancy; and hypersensitivity."

TOCOLYTICS
MAGNESIUM SULFATE: Pregnancy Category A
http://www.drugs.com/pregnancy/magnesium-sulfate.html
“Studies in pregnant women have not shown evidence of fetal risk if magnesium sulfate is administered during any trimesters of pregnancy. However, because studies cannot completely rule out the possibility of harm, magnesium sulfate injection is only recommended for use during pregnancy when benefit outweighs risk.”

“Newborns may show signs of magnesium toxicity (i.e. respiratory and/or neuromuscular depression) if the mother has received intravenous magnesium sulfate prior to delivery (especially if for a period of longer than 24 hours). Equipment for assisted ventilation as well as intravenous calcium should be immediately available for the first 24 to 48 hours after delivery. One study has reported that maternal magnesium sulfate treatment is associated with reduced brain blood flow perfusion in preterm infants. However, intravenous magnesium sulfate did not lead to lower neonate Apgar scores in a study of women treated for preeclampsia even though the newborns cord level indicated hypermagnesemia.”

TERBUTALINE (BRETHINE): Pregnancy Category B
http://www.drugs.com/sfx/brethine-side-effects.html
“Terbutaline has been shown to cross the placenta, and the fetus may experience the general adverse effects reported in the mother. Pulmonary edema has been associated with the intravenous use of terbutaline in pregnant women. Myocardial necrosis in one infant was thought to be associated with terbutaline given at a rate of 0.5 mg/hr for 12 weeks by subcutaneous infusion. In one retrospective review of 8,709 patients receiving continuous low-dose subcutaneous infusion of terbutaline to arrest preterm labor, only 47 (0.54%) had one or more cardiopulmonary problems. Pulmonary edema was reported in 28 patients (0.32%), 17 of whom had been treated concurrently with large amounts of IV fluids or one to three tocolytic agents and four of whom had been diagnosed with pregnancy-induced hypertension and/or multiple gestation. Other cardiovascular effects occurred in 19 patients (0.22%), including electrocardiogram changes, irregular heart rate, chest pain, or shortness of breath. However, 7 of these patients had a history of cardiac problems. Use of terbutaline in pregnant women for the relief of bronchospasm may interfere with uterine contractility. For the treatment of asthma, administration by metered dose inhaler results in lower plasma concentrations and consequently fewer adverse effects for the mother and fetus. Hepatitis has been reported in at least two patients receiving terbutaline to control premature labor.”

“Terbutaline has been assigned to pregnancy category B by the FDA. Animal studies have failed to reveal evidence of teratogenicity. Terbutaline is only recommended for use during pregnancy when benefit outweighs risk.”

INDOMETHACIN (NSAID): Pregnancy Category C
http://www.drugs.com/pregnancy/indomethacin.html
“Animal studies have failed to reveal evidence of teratogenicity or fetal harm except at doses which result in significant maternal toxicity. There are no controlled data in early human pregnancy. Indomethacin has been used in the management of premature labor. However, fetal hemodynamic changes, premature closure of the ductus arteriosus resulting in neonatal primary pulmonary hypertension, and neonatal oliguric renal failure, oligohydramnios, hemorrhage, and intestinal perforation have been reported as a result of this tocolytic therapy. Indomethacin is only recommended for use during pregnancy when benefit outweighs risk.”

“Indomethacin crosses the placenta. In one study, 26 pregnant patients were administered indomethacin 50 mg orally one time approximately six hours prior to scheduled cordocentesis, at a gestational age of 23.6 to 36.6 weeks. At the time of the procedure, maternal serum indomethacin concentrations ranged from 42 to 690 ng/mL (mean 218 ng/mL) while fetal concentrations ranged from 87 to 496 ng/mL (mean 219 ng/mL). The mean maternal to fetal serum concentration ratio was 0.97. There was no correlation between gestational age and maternal/fetal ratio. Amniotic fluid concentrations averaged 21 ng/mL. Indomethacin has been used successfully in the treatment of premature labor as well as polyhydramnios. In several studies, indomethacin was as effective and better tolerated than beta-agonists for premature labor. However, while earlier reports and studies suggested indomethacin was safe for the fetus or neonate, especially when use was confined to pregnancies of 34 weeks gestation or less, more recent data suggest a substantial increase in the risk of serious fetal or neonatal side effects. Eronen (1993) studied the effects of indomethacin or nylidrin on the fetal and neonatal ductus arteriosus and tricuspid valve function. A total of 84 pregnancies (94 fetuses) with premature labor between 22.9 and 34.0 weeks gestation were evaluated. Ductal constriction occurred in 46/49 (86%) of fetuses (gestational age 24.0 to 34.0 weeks) treated with indomethacin. The gestational age of the fetuses without ductal constriction ranged from 24.3 to 28.6 weeks. Eleven fetuses with ductal constriction also had tricuspid regurgitation. Data from this study suggest increasing reactivity of the ductus with increasing gestational age; although, ductal constriction occurred in one fetus at 22.9 weeks gestation. In addition to hemodynamic changes, other serious sequelae of maternal indomethacin use have been documented. One study compared 57 infants delivered at or before 30 weeks gestation whose mothers received indomethacin for the treatment of premature labor with 57 infants whose mothers had not received indomethacin. The total dose of indomethacin ranged from 50 to 6000 mg (median 425 mg) and the duration of therapy ranged from 1 to 79 days (median 3 days). Necrotizing enterocolitis occurred in 29% of infants exposed to indomethacin compared with an 8% incidence in the control group (p=0.005). Intracranial hemorrhage occurred in 28% of infants in the indomethacin group compared with only 9% in the control group (p=0.02). Maternal use of indomethacin has resulted in reduced fetal urine output and subsequent oligohydramnios, neonatal renal failure, fetal pleural effusion, and ileal perforation. In addition, at least two cases of neonatal lower limb ischemia have been reported following prolonged intrauterine exposure to indomethacin. Fetal echocardiograms after 24 hours of maternal indomethacin therapy and then weekly, thereafter, if long-term therapy is necessary, have been recommended. In addition, assessment of amniotic fluid volume is also recommended.”

RITODRINE (YUPOTAR): Pregnancy Category B
http://www.drugs.com/pregnancy/ritodrine.html
“There are no controlled data in human pregnancy. Neonatal hypoglycemia, tachycardia, and ileus have been reported. Rarely, ketoacidosis resulting in fetal death has been reported. Ritodrine is only recommended for use during pregnancy when benefit outweighs risk.”

Disclaimer: 
The material included on this site is for informational purposes only.
It is not intended nor implied to be a substitute for professional medical advice. The reader should always consult her or his healthcare provider to determine the appropriateness of the information for their own situation.  Krystyna and Bruss Bowman and Bowman House, LLC accept no liability for the content of this site, or for the consequences of any actions taken on the basis of the information provided.  This blog contains information about our classes available in Chandler, AZ and Payson, AZ and is not the official website of The Bradley Method®. The views contained on this blog do not necessarily reflect those of The Bradley Method® or the American Academy of Husband-Coached Childbirth®.