A Guide to Treating Irritable Bowel Syndrome While Breastfeeding

Constipation

Women with IBS are more likely to have constipation than other symptoms. ² Psyllium and polyethylene glycol are two older laxatives that are often used as first-line treatments for constipation. Psyllium is a good choice for nursing mothers because it is not absorbed from the gastrointestinal (GI) tract. Although no published experience exists with polyethylene glycol during breastfeeding, it is very poorly absorbed from the GI tract. Neither of these drugs are likely to affect the nursing infant. If these treatments are not effective, one of the newer agents can be tried.

Lubiprostone is a chloride channel activator that increases chloride, sodium, and fluid excretion into the GI lumen. No information is available on the use of lubiprostone during breastfeeding in humans. The manufacturer reports that the drug and its metabolite are undetectable in rat milk and would not be expected to cause any adverse effects in a breastfed infant.

Linaclotide and plecanatide are guanylate cyclase-C agonists that generate cyclic guanosine monophosphate, which in turn increases chloride and bicarbonate secretion into the GI lumen. This draws fluid into the lumen and accelerates GI transit. Neither medication has information available on use during breastfeeding. However, these two drugs are minimally absorbed from the GI tract because of rapid intestinal metabolism to their constituent peptides. Neither the drugs nor their active metabolites are measurable in plasma after administration of recommended doses. Both drugs are considered acceptable to use during breastfeeding with monitoring of the infant for (unlikely) diarrhea.

Prucalopride is a selective serotonin-4 receptor agonist. It is a GI prokinetic agent that stimulates colonic peristalsis, thereby increasing bowel motility. Prucalopride is pharmacologically similar to cisapride, which was removed from the market because it prolongs the QT interval. Prucalopride has no effect on QT interval even at five times the normal dose and has been marketed safely overseas for 9 years. It was recently approved in the United States for chronic idiopathic constipation, but might be used off-label in IBS-C. The manufacturer reports an unpublished study in eight healthy lactating women who were weaning their infants and given prucalopride 2 mg daily for 4 days. The dose to the breastfed infant was estimated to be 1.74 μg/kg daily or about 6% of the weight-adjusted maternal dosage (the relative infant dose). The manufacturer has received no reports of adverse events in breastfed infants in its postmarketing pharmacovigilance database. Incidentally, prucalopride appears to increase prolactin release, at least in animals, but it has not been studied as a galactogogue.

Diarrhea

For those with diarrhea-focused symptoms, loperamide is often used as a first choice. Loperamide has not been studied during breastfeeding, but the loperamide prodrug, loperamide oxide, has been studied. Maximum loperamide concentration in breast milk was only 0.27 μg/L at 6 hours after the second dose of 4 mg. Use of loperamide in usual dosages during breastfeeding is unlikely to affect the infant.

The nonabsorbable bile acid sequestering resins cholestyramine, colesevelam, and colestipol are other alternatives for diarrhea. They can be effective in patients with diarrhea due to increased amounts of bile acids in the gut lumen from either increased synthesis or impaired reabsorption. Because they are not absorbed from the mother's GI tract, they can be used safely during breastfeeding.

Evidence suggests that microbial imbalance plays a role in some patients. Rifaximin is a rifamycin antimicrobial active primarily in the GI tract. No published experience exists with rifaximin during breastfeeding, but because it is so poorly absorbed from the GI tract, it is unlikely to reach the breast milk or bloodstream of the infant in clinically important amounts or cause adverse effects in breastfed infants after maternal use. Various probiotics have also shown efficacy in IBS-D, although the optimal strains and dosages have not been identified. Various strains of probiotics have been studied to treat mastitis in nursing mothers and probiotics are also given directly to infants, so the risks of probiotic use for IBS appear to be minimal.

Alosetron is a serotonin-3 receptor antagonist that was removed from the market temporarily because it causes nondose-related ischemic colitis in 0.2–0.3% of patients. It is now available through a physician-based risk management program for women with severe IBS-D lasting for at least 6 months and unresponsive to other treatments. No information is available on the use of alosetron during breastfeeding. Because of relatively high protein binding and only moderate bioavailability, exposure of the breastfed infant is likely to be low.

Ondansetron is a serotonin-3 receptor antagonist antiemetic that has been used off-label for IBS-D. Little published information is available on the clinical use of ondansetron during breastfeeding, although it is used for nausea after cesarean section, usually in doses of 4–8 mg intravenously. No adverse infant effects have been reported and the drug has been used in infants. Use after cesarean section appears to not affect the onset of breastfeeding. If ondansetron is required by the mother, it is not a reason to discontinue breastfeeding; however, due to the lack of information, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Eluxadoline is a new drug that is a μ-opioid receptor agonist and a δ-opioid receptor antagonist. No information is available on the use of eluxadoline during breastfeeding. Because of its opioid activity, it is probably best avoided in nursing mothers.

Abdominal Pain

Tricyclic antidepressants (TCAs), such as amitriptyline in low doses (usually 30 mg/day), appear to be effective for abdominal pain in IBS, whereas other classes of antidepressants do not. This might be due in part to the anticholinergic activity of the TCAs that newer agents lack. Even higher doses of TCAs used in maternal depression appear to be well tolerated by breastfed infants, so doses used in IBS are not of concern.

Dicyclomine is an anticholinergic antispasmodic drug used for abdominal pain. It has not been well studied during breastfeeding. However, one possible case of apnea, similar to reactions that have occurred in infants given the drug directly, has been reported in a breastfed infant during maternal use. Dicyclomine should not be used during lactation.

Peppermint oil has antispasmodic properties. It contains menthol, menthone, and menthyl acetate as major ingredients. Minor ingredients include eucalyptol, pulegone, bitter substances, caffeic acid, flavonoids, and tannins. Menthol and eucalyptol are excreted into breast milk in small quantities, but the excretion of other components has not been studied. Although peppermint oil is considered “generally recognized as safe” by the U.S. Food and Drug Administration as a food additive, doses of peppermint oil used in the treatment of IBS are higher at 250–750 mg two to three times daily, so infants should be monitored carefully for GI symptoms if it is used in a nursing mother.

Summary

Most drugs used to treat IBS are acceptable to use during breastfeeding. Although several medications used in IBS have no information on use in nursing mothers, they appear to pose low risk to the breastfed infant. Dicyclomine and eluxadoline should not be used in nursing mothers.