In pregnancy, pharmacokinetics of corticosteroids changes. Systemic corticosteroids are not teratogenic. Pregnant women receiving corticosteroid therapy suffer the same side effects and benefits as do treated women who are not pregnant. Clinical experience suggests no abnormalities of children of mothers treated with usual doses of prednisone and methylprednisolone throughout pregnancy, but premature rupture of amniotic membranes and low birthweight babies may occur. Betamethasone and dexamethasone are used to treat the fetus. The effect on the fetus of bolus doses of methylprednisolone is unknown. Very little corticosteroid ingested by the mother enters her breast milk. Corticosteroid therapy in pregnancy is appropriate to control clinically active maternal illness; to treat an in utero infant suffering from neonatal lupus-associated carditis; in stress doses (in corticosteroid-treated patients) for labor and delivery: and, pre-delivery, to induce fetal lung maturation.
Certain drugs such as troleandomycin (TAO), erythromycin ( Ery-Tab , EryPed 200), and clarithromycin ( Biaxin ) and ketoconazole ( Nizoral ) can reduce the ability of the liver to metabolize (breakdown) corticosteroids and this may lead to an increase in the levels and side effects of corticosteroids in the body. On the other hand, phenobarbital, ephedrine , phenytoin ( Dilantin ), and rifampin ( Rifadin , Rimactane ) may reduce the blood levels of corticosteroids by increasing the breakdown of corticosteroids by the liver. This may necessitate an increase of corticosteroid dose when they are used in combination with these drugs.
There is little evidence as to what percentage of a topical corticosteroid dose is absorbed systemically. Studies investigating systemic effects do not measure how much of the corticosteroid is in the blood, but instead focus on measuring cortisol as a marker of hypothalamic-pituitary-adrenal (HPA) axis suppression. After a few weeks’ treatment with potent or very potent topical corticosteroids temporary HPA axis suppression does occur. However, this resolves upon cessation of the topical corticosteroid, without the need for dose tapering. 5, 19 HPA axis suppression is more marked when topical corticosteroids are applied under occlusion, . with wet wraps.