Drugs in Pregnancy

Do the Benefits Outweigh the Risks?

Anita T. Mosley, PhD, PharmD; Amy P. Witte, PharmD


US Pharmacist. 2013;38(9):43-46. 

In This Article

GI Issues

The most common GI problems that occur during pregnancy include nausea, vomiting, acid reflux, diarrhea, and constipation. Drug therapy may be required when lifestyle modifications cannot provide adequate relief of symptoms.

While nausea and vomiting are common indicators of early pregnancy, an extreme manifestation of the condition is termed hyperemesis gravidarum. Severe hyperemesis gravidarum complications—including weight loss >5% of initial body weight, electrolyte imbalance, and dehydration— are the second most common reason for prenatal hospitalization.[20] A variety of medications with different mechanisms of action that have been used to treat nausea and vomiting of pregnancy are listed in Table 3.[20–22]

Acid reflux is another common problem estimated to occur in 30% to 50% of all pregnancies.[23] Due to the pressure on the uterus, acid reflux during pregnancy is less likely to respond to lifestyle modifications such as elevation of the head when sleeping, eating small frequent meals, or avoiding eating within 3 hours of bedtime.[24] OTC antacids are considered the agents of first choice with the exception of magnesium trisilicate (Gaviscon) and sodium bicarbonate (Neut), which should be avoided during pregnancy. Long-term use of high-dose magnesium trisilicate has been associated with increased risk of fetal nephrolithiasis, hypotonia, and respiratory distress; sodium bicarbonate has been associated with metabolic acidosis and fluid overload.[23] A variety of agents that have been used to treat acid reflex during pregnancy are listed in Table 3.[20–22]

Diarrhea and constipation are also frequent problems associated with pregnancy. Table 3 lists agents used to treat these conditions.[20–22] Castor oil and mineral oil should be avoided for the treatment of constipation. Alosetron (Lotronex) is only indicated for irritable bowel syndrome (IBS)–associated diarrhea. Bismuth subsalicylate (Pepto-Bismol, Kaopectate) should be avoided in pregnancy because the salicylate moiety can lead to increased perinatal mortality.[21]