The final part of this series covers the use of infliximab, anticholinergics/antispasmodics, gastrointestinal stimulants, and anorectal preparations in pregnant and lactating women.
▸ Infliximab (Remicade): Infliximab is a monoclonal antibody used to treat severe Crohn's disease and autoimmune diseases such as ankylosing spondylitis, rheumatoid arthritis, and psoriasis. It binds to and inhibits human tumor necrosis factor-α (TNF-α). Animal reproduction studies have not been conducted with the agent because it does not react with animal TNF-α. Human pregnancy exposure consists of about 30 cases, which are limited to case reports and observational studies. The drug does not appear to represent a significant risk for developmental toxicity. Still, if possible, the best course is to avoid its use in pregnancy. If pregnancy exposure does occur, health care providers are encouraged to register these patients in the Organization of Teratology Information Specialists (OTIS) Autoimmune Diseases in Pregnancy study by calling the toll-free number, 877-311-8972.
▸ Anticholinergics/antispasmodics: These agents have been used for years for peptic ulcer and functional GI disorders such as diarrhea, hypermotility, neurogenic colon, irritable bowel syndrome, ulcerative colitis, and biliary tract spasm. The agents—available under numerous trade names—include atropine, belladonna, dicyclomine, glycopyrrolate, L-hyoscyamine, mepenzolate, methscopolamine, propantheline, and scopolamine. Only atropine, scopolamine, and dicyclomine have sufficient data in pregnancy. There are no reports suggesting that these agents cause birth defects. However, an excessive dose of scopolamine in labor has been associated with newborn toxicity. The other drugs are also probably low risk, but cannot be classified as such because of the very limited or complete lack of human pregnancy experience. However, anticholinergic combinations formulated with phenobarbital or other sedatives should be avoided in pregnancy and lactation. Although the data are very limited, all anticholinergics, except dicyclomine, appear to be compatible with breast-feeding. Dicyclomine is concentrated in milk and has been associated with apnea in one nursing infant.
▸ GI stimulants: Dexpanthenol (Ilopan) is given by intramuscular injection to prevent paralytic ileus after abdominal surgery. Although the drug has been promoted for constipation in pregnant women, there are no reports of its use or studies in pregnant or lactating animals or humans. Thus, the drug should not be given during pregnancy or breast-feeding.
In contrast, another GI stimulant, metoclopramide (Reglan, Maxolon), has substantial human pregnancy experience, primarily as an antiemetic. Although it is considered compatible with pregnancy, its use during breast-feeding is controversial. It has been successfully used as a lactation stimulant at doses of 20–45 mg/day. The drug is excreted into milk, but the estimated dose ingested by a nursing infant from milk is much lower than the therapeutic infant dose. However, mild intestinal discomfort has been observed in two infants. Because of its dopaminergic blocking action, the American Academy of Pediatrics classifies metoclopramide as a drug of potential concern during breast-feeding.
▸ Anorectal preparations: These include a large group of agents that are available in various topical formulations such as creams, ointments, foams, lotions, tissues and pads, and suppositories. With the exception of the hydrocortisone products, all are available over the counter, so you might not know that your patient is using them unless a careful history is taken. The OTC preparations are formulated with low concentrations of various drug mixtures, such as local anesthetics, vasoconstrictors, astringents, antiseptics, emollients/protectants, counterirritants, keratolytics, and wound healing agents. Only a few of these products and drugs have been studied in human pregnancy or lactation, but these preparations are used for their local effects and clinically significant systemic levels are not expected.
About 26% of the corticosteroid is absorbed from hydrocortisone suppositories, but the maximum strength of these products is only 30 mg, so the amount reaching the circulation is clinically insignificant. Therefore, at recommended doses, the use of anorectal preparations during pregnancy or breast-feeding can be considered low risk.
Of the drugs covered in this series, misoprostol and tetracycline cause structural defects, castor oil can induce labor, and mesalamine-containing agents and dicyclomine have caused toxicity in nursing infants. Most GI agents are safe in pregnancy and lactation, but many have insufficient data to judge their risk.