OTC options for treating gastrointestinal issues in pregnancy

Avoid sodium bicarbonate as it may lead to alkalosis. If an antacid isn't enough, consider famotidine (Antodine) 20 mg at bedtime..

Pregnant women will ask you about OTCs for GI complaints. We know nausea and vomiting in pregnancy is common. But be ready to help manage other GI problems if nondrug measures aren't enough.

Heartburn. Suggest an antacid with calcium first or one with aluminum/mag (Maalox, etc).

Considered safe at labeled doses, work quickly and can be taken when symptoms occur. Get our note "Dyspepsia and gastro-esophageal reflux during pregnancy".

Point out that antacids can decrease absorption of iron in prenatal vitamins. Tell women to space these by at least 2 hours.

Avoid sodium bicarbonate as it may lead to alkalosis. If an antacid isn't enough, consider famotidine (Antodine) 20 mg at bedtime when an H2-blocker is needed or omeprazole (Losec) 10 to 20 mg in the morning as the PPI of choice for more severe symptoms.

For further information see notes on..

Constipation. Recommend a bulk laxative (Metamucil, etc). They're not absorbed and considered first-line. But remind women to drink plenty of water and slowly titrate the dose to minimize gas and bloating. Or consider PEG 3350 (Miralax, etc). It's minimally absorbed and may be better tolerated.

Advise saving stimulants (senna, bisacodyl) for short-term use. These may cause cramping, dehydration, etc.
Docusate can also be used in pregnancy but may not help much. And keep in mind, it may already be in prenatal vitamins.

Hemorrhoids. It's okay to suggest external topicals, such as (Anusol or Proctosedyl, etc), an anesthetic (pramoxine, etc) for pain or hydrocortisone 1% cream short-term for more severe itching. Daflon may be used, it is considered safe during pregnancy.

Also advise to avoid phenylephrine products (H-formula) as vessel constriction may reduce blood flow to the uterus.
Get our note "Over-the-counter (OTC) medication in pregnancy".

References

Body C, Christie JA. Gastrointestinal Diseases in Pregnancy: Nausea, Vomiting, Hyperemesis Gravidarum, Gastroesophageal Reflux Disease, Constipation, and Diarrhea. Gastroenterol Clin North Am. 2016;45(2):267-283.
Gomes CF, Sousa M, Lourenço I, Martins D, Torres J. Gastrointestinal diseases during pregnancy: what does the gastroenterologist need to know?. Ann Gastroenterol. 2018;31(4):385-394.