Treating Gastroesophageal Reflux and Heartburn While Breastfeeding

Antacids

Oral antacids can provide rapid short-term relief of acid reflux symptoms. The most common antacids are hydroxide salts of aluminum, calcium, magnesium, or their combinations. Magnesium and calcium are normal components of human milk and the aluminum content of human milk is normally lower than cow's milk and much lower than infant formula.

No published information is available on the aluminum, calcium, or magnesium contents of milk during maternal antacid therapy, but all of the metals are poorly absorbed orally. Although calcium is absorbed, its absorption is limited except in unusual circumstances. To avoid bone loss during lactation, one nursing mother developed hypercalcemia while taking calcium in food and supplements in a total dosage of about 4.7 g/day in addition to 1,243 U of vitamin D daily. ³

When magnesium is administered intravenously in large doses, milk magnesium levels are increased only slightly within the normal range, so oral ingestion is likely to have a negligible effect on milk magnesium levels. ⁴ All sources generally consider antacid use during breastfeeding to be acceptable.

In addition to the acid-neutralizing components, some antacids contain additional ingredients, such as alginic acid and simethicone. Alginic acid or alginate is a harmless polysaccharide derived from brown algae that forms a viscous floating foam or “raft” in the stomach acting as a physical barrier between the gastric contents and the gastroesophageal junction. Simethicone is an antifoaming agent considered to be unabsorbable from the maternal gastrointestinal tract. Even if small amounts were to appear in milk, simethicone is safely given directly to infants, so maternal use is not a concern during breastfeeding.

Histamine H₂-Blockers

Histamine H₂-receptor antagonists are often used to suppress acid secretion in GER. Although they differ in milligram potency and half-life, none is clearly superior to others in treating GER. They can be differentiated from each other by their drug interaction potential and in the amount excreted into breast milk. The amounts of all of these drugs in breast milk are less than the doses administered to neonates. Histamine H₂-receptor blockade is known to stimulate prolactin secretion; gynecomastia and galactorrhea have been reported in nonlactating patients. In addition to H₂-receptor blockade, cimetidine may have nonspecific actions that stimulate prolactin secretion. Oral cimetidine doses of 400 mg four times daily increased serum prolactin by 50–112% in six nonlactating patients. Elevation of prolactin with cimetidine is dose related and results in a relative risk of gynecomastia of 40 with doses >1 g/day. ⁵ The implications of this prolactin increase with respect to nursing mothers are not known.

Cimetidine has the greatest excretion into breast milk of the H₂-blockers, because it is actively secreted into breast milk. It also has the greatest number of documented drug interactions because of its inhibition of several cytochrome P450 enzymes.

Ranitidine is a less potent inhibitor of P450 enzymes than cimetidine, but can cause some drug interactions through this mechanism. Nizatidine has less information on excretion into milk, but amounts in milk are small for both of these drugs. Some sources consider nizatidine unacceptable during breastfeeding because of animal toxicology studies.

Famotidine has the least excretion into milk, the least effect on P450 enzymes, and is the longest acting of the H₂-blockers. Infants receive <2% of the maternal weight-adjusted dosage and considerably less than doses given directly to infants. Famotidine is probably the preferred drug in this class for nursing mothers.

Proton Pump Inhibitors

Proton pump inhibitors (PPIs) are the most effective acid suppressing drugs currently marketed and are generally considered to be the most effective drugs for GER. Only pantoprazole and omeprazole have the information regarding their excretion into breast milk. Pantoprazole has the most published breast milk excretion data. In 12 mothers who were studied, it was undetectable for 80% of the day. After 7 days of therapy, the highest milk concentration averaged only 150 mcg/L.

Omeprazole data consist of only one case in which the peak milk level was 20 mcg/L. Esomeprazole is a single-isomer form of omeprazole and information on omeprazole should apply to it as well, although its equivalent dosage is half that of omeprazole. The newer strontium salt of esomeprazole should probably be avoided because strontium is taken up into bone.

Although none of the PPIs are officially approved in the United States for use in infants, they have all been used safely in neonates and infants. The amounts of pantoprazole and omeprazole excreted into milk are 300–600 times less than doses reportedly given to neonates. In addition to their low excretion into breast milk, stomach acid degrades PPIs, which is why they are marketed as enteric-coated beads. Therefore, any drug in breast milk is likely to be destroyed in the infant's stomach and not systemically absorbed.

Like H₂-blockers, the PPIs can raise serum prolactin. Numerous cases of gynecomastia and a few cases of galactorrhea have been reported, primarily with omeprazole. Cases have also been reported with esomeprazole, lansoprazole, and rabeprazole. Most cases resolved after the drug was discontinued. ⁶

Other Drugs

Baclofen inhibits lower esophageal sphincter relaxation, and is employed rarely in patients with persistent symptoms while taking PPIs. Information on excretion of baclofen into breast milk is limited to two mothers, but both had very low amounts in milk. Although baclofen appears to be acceptable during breastfeeding, the infant should be monitored for excessive sedation.

Prokinetic agents, such as metoclopramide and domperidone, were used in the past to treat GER. Prokinetics are now considered to be ineffective in GER, especially compared with PPIs.

Summary

GER that occurs during breastfeeding can be treated in the same way as in nonlactating women. Lifestyle changes can be tried first, followed by occasional antacids as needed. If these measures are insufficient, a histamine H₂-blocker or PPI can be used. Famotidine appears to be the best H₂-blocker for use during lactation. Information on PPIs during breastfeeding is limited to omeprazole and pantoprazole, so they are preferred.