Fetal safety of drugs used in the treatment of allergic rhinitis: a critical review

Abstract

Allergic rhinitis is the most common allergic disease. Pharmacological interventions are often not used in pregnancy because of alarming information in drug labels and patient information, even when evidence for safety exists.Low-risk therapies could include immunotherapy, intranasal sodium cromoglycate (cromolyn sodium), beclometasone, budesonide and first-generation antihistamines. In a meta-analysis examining the safety of first-generation antihistamines in pregnancy, 200 000 first trimester exposures failed to show increased teratogenic risk. Loratadine is the most studied second-generation antihistamine (with a total patient cohort of 2147 women who were exposed) and does not appear to increase the risk of major congenital malformations; however, it has not been as well studied as the earlier antihistamines. Since desloratadine is the principal metabolite of loratadine, it can be assumed that a similar safety profile would fit for desloratadine as was described for loratadine although no direct human studies have been done. Decongestants have not been conclusively proven to affect the fetal outcome and may be used for short-term relief when no other safer alternatives are available. Intranasal corticosteroids have not been associated with an increase in congenital malformations in humans. Based on efficacy and the fact that there would be little systemic absorption, they can be considered a first-line treatment over oral antihistamines, decongestants and mast cell stabilisers; however, the number of controlled trials in pregnancy is limited. Intranasal corticosteroids are associated with minimal systemic effects in adults and are the most effective therapy for allergic rhinitis. Benefit-risk considerations must, therefore, be done but favour their first-line use during pregnancy. Because fetal safety is paramount, recommendations should be based both on the safety of the drugs during pregnancy and the comparative efficacy of the agent in the treatment of the underlying condition. This review exemplifies the fact that there are many safe treatment options for the clinician when dealing with allergic rhinitis during pregnancy.