Safety of AR Drug Classes During Pregnancy Antihistamines
In 1993, the NAEPP Working Group on Asthma and Pregnancy (the predecessor of APWG) recommended the first-generation agents chlorpheniramine and tripelennamine as the antihistamines of choice during pregnancy, based on duration of availability as well as reassuring animal and human data. However, the ARIA guidelines, published in 2001, conclude that the older antihistamines have an overall unfavorable risk/benefit ratio, even in the nonpregnant population, because of their poor selectivity and their sedative and anticholinergic effects. ARIA recommends that where possible, first-generation antihistamines should no longer be prescribed as AR therapy (SOR-C). In general, second-generation antihistamines are more potent, have a longer duration of action, and produce minimal sedation.
In a joint position statement published in 2000, the American College of Obstetricians and Gynecologists and the American College of Allergy, Asthma and Immunology (ACOG-ACAAI) recommended consideration of cetirizine and loratadine, preferably after the first trimester, for pregnant women who need maximal topical therapy and cannot tolerate chlorpheniramine or tripelennamine. ACOG-ACAAI based this statement on reassuring animal data for these second-generation antihistamines, which carry a Pregnancy B rating, and the fact that they are associated with fewer anticholinergic and sedative effects (SOR-B).
APWG does not mention first-generation antihistamines and recommends cetirizine and loratadine as the second-generation antihistamines of choice for treatment of asthma with comorbid AR. A review published in 2005, focusing on the treatment of AR rather than asthma, suggests there is insufficient evidence to support first-line use of cetirizine and loratadine during pregnancy and recommends first considering chlorpheniramine, tripelennamine, or hydroxyzine if an antihistamine is needed during pregnancy (SOR-B).
Physicians must decide on a case-by-case basis whether to select one of the older, better-studied antihistamines, thought to be safe during pregnancy, or a newer agent that has less adverse impact on quality of life but is less well studied in pregnancy. The dilemma can often be averted by prescribing an intranasal steroid (INS) or cromolyn instead of an oral antihistamine.
J Am Board Fam Med. 2007;20(3):289-298. © 2007 American Board of Family Medicine
BY serves on the respiratory disease advisory councils for Schering Plough, Merck, Boehringer Ingleheim, and AstraZeneca. MK serves on the Speakers Bureau or advisory board for Aventis, Pfizer, and Proctor and Gamble.
Cite this: Treating Asthma and Comorbid Allergic Rhinitis in Pregnancy: A Review of the Current Guidelines - Medscape - Mar 01, 2007.