May 19 2022

Classification of the active ingredient Inhaled budesonide

Risk level in pregnancy: This medicine is classified as Category B.

Budesonide has a remarkable effect corticosteroid, being 25 times more potent than hydrocortisone when administered orally.

Studies on healthy volunteers have shown that over a third of the inhaled dose is deposited in the lung, where it can pass to the plasma. By nasal administration, absorption is more reduced (21%).

This medication subcutaneously administered to experimental animals causes fetal loss, intrauterine growth retardation and disorders of the spine and skull ossification. Both rats and rabbits, the results are similar. It is not known whether the drug crosses the placental barrier, but probably if it does, although the amount transferred to the fetus is presumably low.

Have been published data from a cohort study including three Swedish registration systems covering 99% of babies born during the 1995-1997 period. Were collected 2,014 infants exposed to budesonide inhaled by their mothers during the first months of pregnancy [1]. The drug was administered concurrently with beta-adrenergic bronchodilators in 1,675 cases. 16 patients also received other inhaled corticosteroids.

In the group exposed to budesonide, 76 babies had malformations (3.8%, 95% CI 2.9 to 4.6)), while the whole group of children, the incidence of defects was 3.5%.

According to the study results, there was not an increase in the incidence of defects after exposure to inhaled budesonide, including cleft palate (4 cases in the exposed group vs 3.3)./p>

Based on this and other studies with a more limited number of cases, this medicine is unlikely to present a high risk of producing malformations. However, steroids are known to have a greater risk of producing velopalatal fissure.

In the case of allergic rhinitis, must be carefully weighed the potential benefits of topical budesonide against the possible risk of fetal harm, avoiding or limiting if possible exposure to corticosteroids, especially during the first months of pregnancy.

However, in the case of asthma, poor control of the disease may worsen outcomes for both mother and fetus.

In that case, there is a higher risk of complications, including hypertension, preeclampsia, hyperemesis, vaginal bleeding, induction of labor and possibly a difficult birth. Regarding the fetus, a not well-controlled asthma is associated with an increased risk of perinatal mortality, intrauterine growth retardation, prematurity, low weight for gestational age and neonatal hypoxia.

Proper control maternal asthma can prevent these complications, so likely treatment benefits outweigh the potential risks of malformation or toxicity.

Por lo tanto, las mujeres embarazadas que necesitan ser tratada con este f?rmaco, deben ser advertidos de los posibles efectos de la droga y los beneficios de su uso.

Despite the animal findings, it seems that the possibility of fetal harm is remote if used budesonide during pregnancy. However, because the studies in humans can not rule out the possibility of injury, this drug should be used during pregnancy only if clearly needed.


1: K?ll?n B, Rydhstroem H, Aberg A. Congenital malformations after the use of inhaled budesonide in early pregnancy. Obstet Gynecol. 1999 Mar;93(3):392-5. PubMed PMID: 10074986.

Update 18.07.2009

Meaning of category B

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.