Laxative
PREGNANCY RECOMMENDATION: Compatible
BREASTFEEDING RECOMMENDATION: No Human Data—Probably Compatible
PREGNANCY SUMMARY
Although the published human pregnancy experience is limited, the substances are compatible in pregnancy because only minimal amounts are absorbed without significant change in fluid or electrolyte balance. Several sources have concluded that polyethylene glycol (PEG), either PEG-3350 or PEG-4000 (numbers refer to the average molecular weight) are safe and effective and should be considered as first-line therapy for constipation in pregnancy (1–3).
FETAL RISK SUMMARY
PEG-3350 with electrolytes is a white powder that is dissolved in water. It is indicated for bowel cleansing prior to colonoscopy. The osmotic activity of PEG-3350 and the electrolytes result in virtually no net absorption or excretion of ions so that large volumes can be given without significant change in fluid or electrolyte balance (4,5). Similar properties should be expected for PEG-4000.
Reproduction studies in animals have not been conducted. Studies for carcinogenic effects and impairment of fertility in animals have not been performed (4,5).
It is not known if PEG-3350 or PEG-4000 cross the human placenta. Although the average molecular weights are high (3350 and 4000), only minimal amounts are absorbed and clinically significant exposure of the embryo–fetus should not occur.
In a survey on the choice of colonoscopy preparations for pregnant patients, gastroenterologists favored the use of the PEG solution and avoided oral sodium phosphate, whereas obstetricians tended to prefer oral sodium phosphate over the PEG product (6). However, the majority in both groups avoided the sodium phosphate laxative.
In a 2004 observational open label study, 40 pregnant women with constipation were enrolled at 6–37 weeks’ gestation (mean 21.0 weeks) and given a solution of PEG-4000 for 15 days at a dose of 250 mL once or twice daily (7). Pregnancy outcomes included one spontaneous abortion at 11 weeks’ and two preterm deliveries at 26 weeks’; one for failure of a cervical cerclage and the other for severe gestational hypertension. Of the remaining 37 women, the mean gestational age at delivery was 39.2 weeks. No neonatal complications were observed (7).
A brief 1989 case report described the use of PEG (molecular weight not specified) electrolyte solution in a 18-year-old woman at 38 weeks’ gestation who had ingested 55 tablets of a prenatal iron supplement (8). An x-ray demonstrated many iron tablets in her stomach. A whole bowel irrigation with PEG through a nasogastric tube at 2.0 L/hr was started and continued until the bowels were clear. Deferoxamine also was given for chelation. The patient was subsequently discharged in good health and, 5 weeks later, gave birth to a normal 3550-g female infant with no perinatal complications (8).
BREASTFEEDING SUMMARY
No reports describing the use of PEG-3350 or PEG-4000 during human lactation have been located. However, the substances probably are compatible with breastfeeding because only minimal amounts are absorbed. Large volumes can be given without significant change in fluid or electrolyte balance (4,5).
References
1.Tytgat GN, Heading RC, Muller-Lissner S, Kamm MA, Scholmerich J, Berstad A, Fried M, Chaussade S, Jewell D, Briggs A. Contemporary understanding and management of reflux and constipation in the general population and pregnancy: a consensus meeting. Aliment Pharmacol Ther 3003;18:291–301.
2.Mahadevan U, Kane S. American Gastroenterological Association Institute medical position statement on the use of gastrointestinal medications in pregnancy. Gastroenterology 2006;131:278–82.
3.Mahadevan U, Kane S. American Gastroenterological Association Institute technical review on the use of gastrointestinal medications in pregnancy. Gastroenterology 2006;131:283–311.
4.Product information. Nulytely. Braintree Laboratories, 2008.
5.Product information. Trilyte. Alaven Pharmaceutical, 2008.
6.Vinod J, Bonheur J, Korelitz BI, Panagopoulos G. Choice of laxatives and colonoscopic preparation in pregnant patients from the viewpoint of obstetricians and gastroenterologists. World J Gastroenterol 2007;13:6549–52.
7.Neri I, Blasi I, Castro P, Grandinetti G, Ricchi A, Facchinetti F. Polyethylene glycol electrolyte solution (Isocolan) for constipation during pregnancy: an observational open-label study. J Midwifery Women’s Health 2004;49:355–8.
8.Van Ameyde KJ, Tenenbein M. Whole bowel irrigation during pregnancy. Am J Obstet Gynecol 1989;160:646–7.