II. Class A: No risk in controlled human studies
III. Class B: No risk in controlled animal studies
- Milk of Magnesia
- Doxylamine
- Metoclopramide
- 
                          Calcium Carbonate (Tums)- Pregnancy risk class is unknown, but appears safe in pregnancy
- First choice agent of the Antacids in pregnancy
- Crosses the placenta
- Risk of Milk-Alkali Syndrome at high dose
- May interfere with iron absorption
 
- Aluminum hydroxide (Maalox, Mylanta)- Pregnancy risk class is unknown, but appears safe in pregnancy
- May interfere with iron absorption
- Neurotoxicity and fetal malformation risk at high dose
 
- 
                          Magnesium Hydroxide or Magnesium carbonate (Maalox, Mylanta)- Pregnancy risk class is unknown, but appears safe in pregnancy
- May interfere with iron absorption
 
- 
                          Kaolin-pectin (Kaopectate)- Previously considered antidiarrheal of choice in pregnancy but now contains bismuth and Aspirin
- Not absorbed but risk of Iron Deficiency Anemia
 
- Sucralfate
- Meclizine (Antivert)
- Mesalamine
- Ranitidine (Zantac)
- 
                          Cimetidine (Tagamet)- Crosses placenta but considered safe
- Used as second line after Maalox, Mylanta or tums
- Ranitidine may be preferred over Cimetidine for longer term use
 
- 
                          Famotidine (Pepcid)- Limited human data
- Crosses the placenta
 
- Lactulose
- 
                          Simethicone
                          - Not absorbed and does not cross the placenta, so considered safe in pregnancy
 
- 
                          Proton Pump Inhibitors- Cross the placenta
- FDA Category B as a class including Esomeprazole (Nexium), Rabeprazole (Aciphex) and Lansoprazole (Prevacide)
- FDA Category C for Omeprazole (Prilosec) based on animal studies, but appears safe in pregnancy and is best studied of the PPI agents (see below)
 
IV. Class C: Small risk in controlled animal studies
- Hydroxyzine (Vistaril)
- Prochlorperazine (Compazine)
- Droperidol (Inapsine)
- Metamucil
- 
                          Bismuth Subsalicylate (Pepto Bismol)- Risk of Salicylate absorption
- Not recommended in pregnancy (especially in second and third trimester due to Aspirin component)
 
- 
                          Loperamide (Imodium)- Possible associations with fetal cardiovascular defects
- Avoid in first trimester
 
- 
                          Atropine-Diphenoxylate (Lomotil)- Class D in third trimester
- Not recommended in pregnancy
 
- 
                          Nizatidine (Axid)- Avoid in pregnancy
- IUGR, fetal death and abortion seen in rabbit studies
 
- Docusate Sodium (Colace)
- Promethazine (Phenergan)
- Senna
- 
                          Polyethylene Glycol 3350 (Miralax)- Preferred Laxative for Constipation in Pregnancy
 
- 
                          Omeprazole
                          - FDA Category C for Omeprazole (Prilosec) based on animal studies
- However appears safe in pregnancy and is best studied of the PPI agents
 
- 
                          Mineral Oil
                          - Not absorbed (and does not cross the placenta)
- Avoid in pregnancy
- Risk of fat soluble Vitamin Decreased absorption (risk of neonatal Coagulopathy and bleeding complications)
 
V. Class X: Very high risk to the human fetus
- Misoprostol
- Bismuth Subsalicylate (Pepto Bismol) in trimester 3
- Castor Oil
VI. References
- Briggs (1998) Drugs in Pregnancy and Lactation, 5th ed, Lippincott Williams and Wilkins, Philadelphia, PA
- Briggs (2008) Drugs in Pregnancy and Lactation, Lippincott Williams and Wilkins, Philadelphia, PA
- Black (2003) Am Fam Physician 67(12):2517-24 [PubMed]
- Larimore (2000) Prim Care 27(1):35-53 [PubMed]
- Servey (2014) Am Fam Physician 90(8): 548-55 [PubMed]
