GI agents: Part II.(DRUGS, PREGNANCY, AND LACTATION)

The second part of this three-part series examines the safety of agents used to treat several gastrointestinal diseases that cause significant morbidity in pregnant women.

* Helicobacter pylori infection: The bacteria H. pylori are associated with chronic active antral gastritis, duodenal ulcer, and gastric ulcer. Although controversial, several studies have associated this infection with severe nausea/vomiting of pregnancy, including hyperemesis gravidarum. Eradication regimens involve dual, triple, or quadruple therapy, typically given for 2 weeks, combining one or two anti-infectives and an antisecretory agent. Bismuth and ranitidine bismuth citrate may be added to the regimen. If clinically acceptable, it is best to delay therapy until after the first trimester. Of the four anti-infectives in these regimens (amoxicillin, clarithromycin, metronidazole, and tetracycline), only tetracycline clearly causes developmental toxicity, but the carcinogenic potential of metronidazole has not been adequately assessed.

Two proton pump inhibitors, lansoprazole (Prevacid) and omeprazole (Prilosec, Zegerid), are the antisecretory agents of choice in H. pylori eradication regimens because neither appears to represent a significant risk in pregnancy. Although ranitidine (Zantac) is compatible with pregnancy, both the salt form ranitidine bismuth citrate (Tritec) and bismuth alone are best avoided because the limited human data prevent an accurate assessment of bismuth's risk to the embryo or fetus.

Amoxicillin, clarithromycin, and tetracycline are compatible with breast-feeding. The other agents used for H. pylori infection are best avoided in lactation because of potential toxicity to the infant.

* Cholelithiasis: Only one gallstone-solubilizing agent, ursodiol (Actigall, Urso), is available in the United States. Reports of exposure to this agent early in pregnancy are limited, but there are more data in the second half of pregnancy, which indicates that the drug does not appear to represent a risk in pregnancy or lactation.

* Digestive enzymes: Two digestive pancreatic enzymes--pancreatin and pancrelipase--are used for various conditions that result in deficient pancreatic secretions, such as cystic fibrosis and chronic pancreatitis. These enzymes metabolize fats, proteins, and starches in the duodenum and upper jejunum. Only fragments of pancreatin and pancrelipase are absorbed systematically. Although human data are limited, animal data suggest these enzymes are low risk in pregnancy and lactation. Of note, the enteric coating on many of ...