Terbutaline

 Risk Factor: BM
 Class: AUTONOMICS / Sympathomimetics (Adrenergics)

Contents of this page:

Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers

Fetal Risk Summary

Terbutaline is a b-sympathomimetic indicated for the prevention and reversal of bronchospasm. During pregnancy it is primarily used as a tocolytic agent. No reports linking the use of terbutaline with congenital defects have been located. However, the tocolytic use of this drug is confined to the late 2nd and early 3rd trimesters. Published reports describing the use of terbutaline as a bronchodilator during early pregnancy have not been found.

Reproduction studies in mice, rats, and rabbits at doses up to 1500 times the SC maximum recommended human daily dose of 0.1 mg/kg have revealed no evidence of impaired fertility or fetal harm (1).

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, 149 newborns had been exposed to terbutaline during the 1st trimester (F. Rosa, personal communication, FDA, 1993). A total of seven (4.7%) major birth defects were observed (six expected), including three cardiovascular defects (two expected) and one oral cleft (none expected). No anomalies were observed in four other categories of defects (spina bifida, polydactyly, limb-reduction defects, and hypospadias) for which specific data were available. These data do not support an association between the drug and congenital defects.

Terbutaline rapidly crosses the placenta to the fetus (2). In seven women given 0.25 mg IV during the second stage of labor, cord blood levels 760 minutes after the dose ranged from 12% to 55% (mean 36%) of maternal serum.

Terbutaline has been used as a tocolytic agent since the early 1970s (3,4). The incidence of maternal side effects is usually low (e.g., 5% or less) but may be severe (3,5,6,7,8 and 9). A 1983 review listed the more serious side effects of parenteral b-sympathomimetic therapy (e.g., terbutaline, ritodrine) as pulmonary edema, myocardial ischemia, cardiac arrhythmias, cerebral vasospasm, hypotension, hyperglycemia, and miscellaneous metabolic alterations (hypokalemia, increased serum lactate, and a decrease in measured hemoglobin concentration) (10). The more serious adverse effects are seen with continuous infusions of these drugs. Avoidance of this route of administration as well as careful selection of patients, appropriate dosing, and close monitoring of patient status may help to prevent serious maternal effects.

Terbutaline may cause fetal and maternal tachycardia (3,5,6 and 7). Fetal rates are usually less than 175 beats/minute (6). As mentioned previously, maternal hypotension may occur, especially in the bleeding patient (10). More commonly, increases in systolic pressure and decreases in diastolic pressure occur with no reduction in mean arterial pressure and, thus, do not adversely affect the fetus (7,10,11).

Like all b-mimetics, terbutaline may cause transient maternal hyperglycemia followed by an increase in serum insulin levels (3,12,13). Sustained neonatal hypoglycemia may be observed if maternal effects have not terminated before delivery (12). Maternal glucose intolerance was observed at 1 hour in 19 of 30 patients receiving oral terbutaline for at least 1 week (14). Although macrosomia was not observed, the birth weights (after adjustment for gestational age) of infants from terbutaline-treated mothers had a tendency to be greater than those of babies from comparable controls (14).

Sudden, unexplained intrapartum death in a fetus at 30 weeks' gestation occurred 5 hours after the start of an IV infusion of terbutaline for premature labor (15). No evidence of uterine, placental, or fetal anomalies was discovered.

Myocardial necrosis in a newborn was reported in 1991 (16). A continuous SC infusion of terbutaline (initial dose 0.5 mg/hour) was started at 25 weeks' gestation for premature labor in a 22-year-old woman with gestational diabetes. Therapy was continued until delivery at 37 weeks' of a 2850-g male infant. Tachypnea (80100 breaths/minute) developed shortly after birth and chest radiography demonstrated mild cardiomegaly with increased pulmonary vascularity (16). A right ventricular biopsy obtained during cardiac catheterization showed marked myocardial fiber degeneration and focal bizarre nuclear dysmorphism (16). These findings were believed to be caused by catecholamine excess. Normal electrocardiogram and echocardiogram were found on examination at 1 month of age.

Maternal liver impairment was reported in a patient after 1 week of continuous IV administration of terbutaline (17). Therapy was stopped and 1 week later a healthy newborn was delivered without signs of liver toxicity.

A paradoxical reaction to terbutaline was observed in a patient after 0.25 mg IV produced marked uterine hypertonus and subsequent severe fetal bradycardia (<50 beats/minute) (18). A healthy baby was delivered by emergency cesarean section.

Terbutaline has been used frequently to treat intrapartum fetal distress (19,20,21,22 and 23). The mechanism of the beneficial effects on fetal pH and heart rate is thought to be caused by relief of the ischemia produced by uterine contractions on the placental circulation.

Although maternal complications may occur, few direct adverse effects, other than transient tachycardia and hypoglycemia, and the single report of myocardial necrosis, have been observed in the fetus or newborn. In many studies, neonatal complications are minimal or nonexistent (24,25,26,27 and 28). Compared with controls, prophylactic terbutaline in low-risk patients with twin gestations has produced significant gains in birth weights caused by longer gestational times (27). In addition, terbutaline decreases the incidence of neonatal respiratory distress syndrome in a manner similar to other b-mimetics (29). Long-term evaluation of infants exposed to terbutaline in utero has been reported (30,31 and 32) . No harmful effects in the infants (224 months) have been found.

In summary, terbutaline has been used as a tocolytic since the early 1970s. Only rare reports of serious toxicity in the fetus or newborn have appeared, and although maternal adverse effects are much more common, toxicity in both are no more frequent than with other b-mimetics used for the treatment of premature labor. Avoidance of continuous terbutaline infusions lessens the chance of serious maternal effects. The manufacturer has now categorized the drug as not indicated for the management of preterm labor, but this was apparently done for regulatory concerns as published information does not support the reclassification.

Breast Feeding Summary

Terbutaline is excreted into breast milk (33,34). In two mothers with chronic asthma about 68 weeks postpartum, 5 mg 3 times daily produced mean maternal plasma levels of 1.94.8 ng/mL, whereas milk concentrations ranged between 2.5 and 3.8 ng/mL (33). The nursing infants ingested approximately 0.2% of the maternal dose, and the drug could not be detected in their plasma. In the second report, two mothers, both at 3 weeks postpartum and both with chronic asthma, were treated with 2.5 mg 3 times a day (34). Plasma levels varied between 0.97 and 3.07 ng/mL, whereas mean milk levels were 2.763.91 ng/mL. Peak milk concentrations occurred at about 4 hours. The milk:plasma ratios of 1.42.9 are indicative of ionic trapping in the milk (34). Concentrations of terbutaline were highest in the fat fraction of the milk. Based on calculations, the infants were ingesting approximately 0.7% of the maternal dose.

No symptoms of adrenergic stimulation were observed in the four infants and all exhibited normal development. Long-term effects of this exposure, however, have not been studied. The American Academy of Pediatrics considers terbutaline to be compatible with breast feeding (35).

References

1. Product information. Brethine. Novartis Pharmaceuticals, 2000.
2. Ingemarsson I, Westgren M, Lindberg C, Ahren B, Lundquist I, Carlsson C. Single injection of terbutaline in term labor: placental transfer and effects on maternal and fetal carbohydrate metabolism. Am J Obstet Gynecol 1981;139:697701.
3. Haller DL. The use of terbutaline for premature labor. Drug Intell Clin Pharm 1980;14:75764.
4. Ingemarsson I. Cardiovascular complications of terbutaline for preterm labor. Am J Obstet Gynecol 1982;142:117.
5. Andersson KE, Bengtsson LP, Gustafson I, Ingermarsson I. The relaxing effect of terbutaline on the human uterus during term labor. Am J Obstet Gynecol 1975;121:6029.
6. Ingermarrson I. Effect of terbutaline on premature labor. A double-blind placebo-controlled study. Am J Obstet Gynecol 1976;125:5204.
7. Ravindran R, Viegas OJ, Padilla LM, LaBlonde P. Anesthetic considerations in pregnant patients receiving terbutaline therapy. Anesth Analg (Cleve) 1980;59:3912.
8. Katz M, Robertson PA, Creasy RK. Cardiovascular complications associated with terbutaline treatment for preterm labor. Am J Obstet Gynecol 1981;139:6058.
9. Ingemarsson I, Bengtsson B. A five-year experience with terbutaline for preterm labor: low rate of severe side effects. Obstet Gynecol 1985;66:17680.
10. Benedetti TJ. Maternal complications of parenteral b-sympathomimetic therapy for premature labor. Am J Obstet Gynecol 1983;145:16.
11. Vargas GC, Macedo GJ, Amved AR, Lowenberg FE. Terbutaline, a new uterine inhibitor. Ginecol Obstet Mex 1974;36:7588.
12. Epstein MF, Nicholls RN, Stubblefield PG. Neonatal hypoglycemia after beta-sympathomimetic tocolytic therapy. J Pediatr 1979;94:44953.
13. Westgren M, Carlsson C, Lindholm T, Thysell H, Ingemarsson I. Continuous maternal glucose measurements and fetal glucose and insulin levels after administration of terbutaline in term labor. Acta Obstet Gynecol Scand 1982;Suppl 108:635.
14. Main EK, Main DM, Gabbe SG. Chronic oral terbutaline tocolytic therapy is associated with maternal glucose intolerance. Am J Obstet Gynecol 1987;157:6447.
15. Lenke RR, Trupin S. Sudden, unforeseen fetal death in a woman being treated for premature labor: a case report. J Reprod Med 1984;29:8724.
16. Fletcher SE, Fyfe DA, Case CL, Wiles HB, Upshur JK, Newman RB. Myocardial necrosis in a newborn after long-term maternal subcutaneous terbutaline infusion for suppression of preterm labor. Am J Obstet Gynecol 1991;165:14014.
17. Suzuki M, Inagaki K, Kihira M, Matsuzawa K, Ishikawa K, Ishizuka T. Maternal liver impairment associated with prolonged high-dose administration of terbutaline for premature labor. Obstet Gynecol 1985;66:14S15S.
18. Bhat N, Seifer D, Hensleigh P. Paradoxical response to intravenous terbutaline. Am J Obstet Gynecol 1985;153:3101.
19. Tejani NA, Verma UL, Chatterjee S, Mittelmann S. Terbutaline in the management of acute intrapartum fetal acidosis. J Reprod Med 1983;28:85761.
20. Barrett JM. Fetal resuscitation with terbutaline during eclampsia-induced uterine hypertonus. Am J Obstet Gynecol 1984;150:895.
21. Ingemarsson I, Arulkumaran S, Ratnam SS. Single injection of terbutaline in term labor. I. Effect on fetal pH in cases with prolonged bradycardia. Am J Obstet Gynecol 1985;153:85965.
22. Ingemarsson I, Arulkumaran S, Ratnam SS. Single injection of terbutaline in term labor. II. Effect on uterine activity. Am J Obstet Gynecol 1985;153:8659.
23. Mendez-Bauer C, Shekarloo A, Cook V, Freese U. Treatment of acute intrapartum fetal distress by b2-sympathomimetics. Am J Obstet Gynecol 1987;156:63842.
24. Stubblefield PG, Heyl PS. Treatment of premature labor with subcutaneous terbutaline. Obstet Gynecol 1982;59:45762.
25. Caritis SN, Carson D, Greebon D, McCormick M, Edelstone DI, Mueller-Heubach E. A comparison of terbutaline and ethanol in the treatment of preterm labor. Am J Obstet Gynecol 1982;142:18390.
26. Kaul AF, Osathanondy R, Safon LE, Frigoletto FD Jr, Friedman PA. The management of preterm labor with the calcium channel-blocking agent nifedipine combined with the b-mimetic terbutaline. Drug Intell Clin Pharm 1985;19:36971.
27. O'Leary JA. Prophylactic tocolysis of twins. Am J Obstet Gynecol 1986;154:9045.
28. Arias F, Knight AB, Tomich PB. A retrospective study on the effects of steroid administration and prolongation of the latent phase in patients with preterm premature rupture of the membranes. Am J Obstet Gynecol 1986;154:105963.
29. Bergman B, Hedner T. Antepartum administration of terbutaline and the incidence of hyaline membrane disease in preterm infants. Acta Obstet Gynecol Scand 1978;57:21721.
30. Wallace R, Caldwell D, Ansbacher R, Otterson W. Inhibition of premature labor by terbutaline. Obstet Gynecol 1978;51:38793.
31. Svenningsen NW. Follow-up studies on preterm infants after maternal b-receptor agonist treatment. Acta Obstet Gynecol Scand 1982;Suppl 108:6770.
32. Karlsson K, Krantz M, Hamberger L. Comparison of various b-mimetics on preterm labor, survival and development of the child. J Perinat Med 1980;8:1926.
33. Lonnerholm G, Lindstrom B. Terbutaline excretion into breast milk. Br J Clin Pharmacol 1982;13:72930.
34. Boreus LO, de Chateau P, Lindberg C, Nyberg L. Terbutaline in breast milk. Br J Clin Pharmacol 1982;13:7312.
35. Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 1994;93:13750.
    
    

Questions and Answers

Ok so I am 36 weeks pregnant and I have now been given Terbutaline 4 different times!! Is this harming my baby?

In the past 2 weeks I have gone to the hospital with contractions 4 times now!! I am dilated to 3.5 and am 36 weeks pregnant, but their solution is another shot of Terbutaline. It has not worked the past 3 times and I am still contracting. I am scared that having so much of this in such a short time is harming my baby!!! Is it or am I just freaking out?

I had a T-pump) from 26 to 36 weeks when I delivered. I believe it had a profound effect on my daughter for the first year. Similar to crack symptoms (never did crack and didn't drink caffeine).

She startled very easy and had shakes. As she grew her anxiety subsided. The heart racing effect it has on you also effects the baby.

In the long run she was better off staying inutero for that extra 10 week. Prematurity is was more damaging.

How long after you stopped taking terbutaline did you go into labor?

I am 33 weeks pregnant and was prescribed terbutaline on Monday night for preterm labor. My husband and I did some research about the drug and did not like the side effects, so I decided to stop taking it. I talked to my doctor and she said that its fine that I don't take it. I am currently 25% effaced and not dialated, I just wondered if others went through this and how long after they stopped taking it did they go into labor. Also, my FFN test came back negative.

With my 2nd child I went off it at 36 weeks and was induced at 38 weeks because I was dilated to 4 CMS and was in alot of pain. With my 3rd I didn't use it consistantly...only as needed for stopping the contractions and she was born around 37 weeks.

Good for you doing your homework on the med and talking to your doc about not taking it! Good luck!

Does anyone know about any bad affects of taking Terbutaline for preterm labor?

I am currently 36 weeks pregnant, and my doctor had me start taking terbutaline last week because i was having contractions...
I am concerned that it might be harming the baby... for terbutaline is not FDA approved for preterm labor... though it is widely used to treat preterm labor... It relaxes the muscles in the uterus so it won't contract...

i was given that with my 1st pregnancy at the hospital and was sent home with some to continue taking even though they had stopped the contractions. it made me feel very crappy and gave me a very rapid heartbeat and cold sweats. i saw my ob the following morning and he took me off immediately.

33 weeks pregnant and dilated 3 centimeters?

I am 33 weeks pregnant and I have been having contractions that are painless. I had 6 contractions in one hour. I tried laying down on my left side and drinking water. When I go to pee I contract even more. I went to the doctor this morning and I was dilated 2 centimeters. Now I am at the Hospital and I am 3 centimeters. I have been taking this medicine Terbutaline for about a weeks. Which isn't working!!. Could this mean I am going in to preterm labor.

I had the same thing happen to me when i was pregnant with my son. He was born at 34 weeks, It is possible that you are going into preterm labor. I will say that at 33 weeks your baby would be fine. But it is your doctor who will make the call if it is preterm labor. In any case the best of luck to you and the little one.

35 weeks pregnant and been injected by terbutalin?

Does anyone know if its safe to have terbutaline injection to slow the labor? Im 35 weeks and I just went to the doctor becasue Im having contractions and he prescribed the nurse for me to have a terbutalline. I know that that med is for asthmatis people....If anyone has an idea I would really appreciate it. Thanks!

If your doctor has prescribed it, then it's okay. I don't know exactly what the medicine is used for but I know that the muscular tissue of the uterus is the same as some other tissues in our body like f.e. the intestines. So when our body produces a hormone that relaxes the uterine tissue, a side effect is relaxation of all those similar tissues and of course, the slow-down of our intstines leads to constipation. Or when labor starts urged by a hormone that makes that tissue contract, it affects all those similar tissues and as a result you might have several BMs in close succession. So if a medicine is used to relax a contracted tissue in asthmatics, my guess is it also works to relax a contracted uterus.

i am 33 weeks pregnant and need seriouse people 2 anwser this question?

i went to hospital 2 days ago because i was in pre term labor they gave me 2 shots terbutaline and it work but yesterday i started losing my mucus plug is this normal? please only serious reply!

Sounds like your starting Labor!! The shots only subside the early Labor for a short time. But since you have lost the mucus plug, I would definitely think Labor is around the corner for you! But don't worry, it could be between a couple of days up to a couple weeks before the Labor actually starts! Just keep your senses open to all those signs, cramping in the lower abdomen following around to your backside, tightening of your lower abdomen with cramping starting out dull then intensifies, hips are achy, leaking of the bag of water, and no matter what position you try to get comfy in, the symptoms persist to be the same! Don't forget to time these also! And considering your a bit early, if these symptoms persist, go to the triage to be evaluated!! If the baby wants to come now, it will!

35 Weeks Pregnant and on bedrest for incompetent cervix. Anyone out there had this experience?

My cervix is dilated 2.5 cm and is 1.4 cm in length. I am on Brethine (Terbutaline) every 4 hours to keep contractions at bay... Do you think I am close to labor? I was in the hospital for 2.5 weeks and recently got out. The baby is very low and probably pushing on my cervix. Just wondering if anyone else had a similar experience????

yes hun i have been there i have an incompetant cervix also i spent 4 mon in the hospital on bedrest.. if u like hit me up on yahoo msngr cowgirl_71023 i would be more than happy to talk to you about all of this..there will be alot of pressure on your cervix the more you stay in bed the better you are .. im curious if you were givin steroids to help the babies lungs develope faster plz hit me up i am here for you

Anyone ever had to take Terbutaline to stop contractions?

I am 24 w 2 d pregnant and yesterday I went in to L&D because I was having very watery discharge-the on-call nurse said to go in to L&D to make sure it was not amniotic fluid...good news is that it was not and my cervix was closed but turned out I was having contractions every 3 or 4 minutes...I could not even feel them. Anyway-they gave me fluids and Terbutaline. I have to take it every 4 hours around the clock. Anyone else had to do this? Did it stop your contractions? I am just worried since I didnt even know I was having them. Also, did it make you feel like you couldnt stop shaking? Anyway-just any experience any of you have with this would be great! Did you still carry to 38-40 weeks? Thanks! =)

I work in high-risk L&D, and we use terbutaline a lot on women who are having preterm labor. It is safe and pretty effective in most cases. And yes, it is normal to feel somewhat jittery like you drank too much coffee. Usually those side effects will lessen after you have been on the medication for a few days and your body adapts to it.

I am 32 Weeks pregnant. How much longer?

Ok I know that I am not term. I have had to go to triage with contractions and they had to give me terbutaline and them they started me on steriods for the baby's lungs. They told me I was 1-2 cm dilated and 50 effaced and at -2 station.

Ok I have loose bowels , uncomfortable sparatic contractions and a tingling sensation in the belly. Just curious to see if anyone has an idea about whether I am the prelabor stage or not.

Are you having more than 6 contractions in one hour? If so, go back to the hospital immediately. If not, just rest and take it easy. We can't predict what will happen. Some women have an episode of early contractions that require meds to stop them, but have no further problems and end up going past due. Loose bowels could be related to many things, not just labor. Tingling is a vague symptom which is not typical of labor. Contractions are the main thing you need to pay attention to, that is the only true sign of preterm labor. Also, if you start bleeding, or if your start leaking fluid / membranes rupture, that's another sign that things could be happening.

If you are ever not sure. . . call your doctor. Even on the weekends they have after-hours answering services and the doctor on-call will phone you back at home. Let them make the decision if you need to be seen at the hospital or not - that's their job.