The latest drug classification for pregnancy (five classes: A, B, C, D, X) issued by the FDA (Food and Drug Administration – one of the most stringent drug review agencies in the world) is defined below, and the FDA classification of drugs related to inflammatory bowel disease (IBD) is detailed below for clinical reference and quick reference in selecting safe drugs for use during pregnancy.
5-Aminosalicylic acid (5-ASA) All 5-aminosalicylic acid drugs (salazosulfapyridine, mesalazine and balsalazide) are classified as Class B, except for olsalazine, which is classified as Class C for use during pregnancy. Several studies have shown that the aminosalicylates are safe for use in pregnancy. However, because of their ability to antagonize folic acid, it is recommended that pregnant women take folic acid at 2 mg daily for the entire duration of their pregnancy prior to delivery. except for occasional diarrhea in the infant, administration of salazosulfapyridine is not harmful to breastfeeding.
Infliximab (IFX) IFX is an IgG1 antibody with a class B use in women during pregnancy. IFX does not cross the placenta in early pregnancy, but can do so very efficiently in mid- and late-pregnancy. The fetus is protected from exposure to IFX during the critical period of organogenesis. adalimumab ADA has a class B use in women in pregnancy and is approved by the FDA for the induction and maintenance of CD remission. the safety of ADA in patients with UC has not been explored.
Corticosteroids Corticosteroids are used during pregnancy as a C drug. Women who apply corticosteroids in early pregnancy have an increased incidence of cleft lip and palate in their newborns. However, the results of the studies are inconsistent. Overall, there is a small risk to the developing infant with corticosteroids, but pregnant women should be informed of the benefits and risks of corticosteroid therapy.
Methotrexate Methotrexate has a class C use in women during pregnancy, is teratogenic, and should not be used in women considering pregnancy.
Azathioprine and 6-mercaptopurine 6-MP and AZA have a class D use level in women during pregnancy. Animal studies have shown that rats to which AZA was applied had a higher incidence of malformations such as cleft lip and palate, ocular malformations and skeletal muscle abnormalities. However, the conclusions in the literature are inconsistent, suggesting that 6-MP/AZA application in pregnancy should be individualized.
Cyclosporine and Tacrolimus The class of use for cyclosporine in women during pregnancy is C. For severe, hormone-resistant UC, cyclosporine may be an option if surgical treatment would have an impact on the mother and fetus.
Metronidazole Metronidazole is a class B for use in pregnancy. It should be used primarily for CD perianal lesions. It is excreted through breast milk and breastfeeding should be discontinued within 12-24 hours after single dose administration. Long-term use is not recommended considering toxicity.