GUIDELINES FOR PRESCRIBING NEWER ASTHMA DRUGS DURING PREGNANCY

Several new families of asthma and/or allergy drugs have arrived since the landmark guidelines from the National Asthma Education Program Working Group on Asthma and Pregnancy were released in 1993. A joint committee of the American College of Obstetricians and Gynecologists (ACOG) and the American College of Allergy, Asthma and Immunology (ACAAI) was recently convened to provide guidance for physicians on asthma management in pregnant patients, particularly with regard to the use of newer asthma and allergy medications.[1] The committee's recommendations include:

• A stepped approach, beginning with inhaled ß 2-agonists for mild, intermittent asthma and including inhaled cromolyn for mild persistent asthma; inhaled corticosteroids for moderate persistent asthma; and inhaled plus oral corticosteroids for severe persistent asthma (Table 1).
• Use of either beclomethasone or budesonide if inhaled corticosteroids are initiated during pregnancy.
• Consideration of inhaled salmeterol instead of, or in addition to, theophylline for asthma that is not controlled by inhaled corticosteroids.
• Avoidance of oral decongestants during the first trimester.

In general, the committee preferred inhaled medications (because they have fewer systemic effects) and time-tested drugs (because of greater experience with their use during pregnancy). Physicians are advised to limit medication use as much as possible during the first trimester, although birth defects related to most asthma drugs are uncommon.

SEVERITY OF DISEASE IS KEY

Michael Schatz, MD, a member of the joint committee, discussed the new recommendations in an interview with PULMONARY REVIEWS. "The first step in treating a pregnant woman who has asthma is to establish the severity of her asthma and to determine the level of control provided by her current medication, if any. Relating the level of control to the patient's current medications can help clinicians judge the severity of asthma," said Dr. Schatz, a Clinical Professor in the Department of Medicine at the University of California, in San Diego, and Chief of Allergy at Kaiser-Permanente Medical Center in San Diego.

"Patients should be counseled to do everything they can during pregnancy to avoid asthma and allergy triggers, including cigarette smoke and allergens. Avoidance can potentially reduce the need for medication," Dr. Schatz said. "If the patient is taking allergen immunotherapy shots, has had a positive response, and is not experiencing systemic reactions, these should be continued. However, it is not recommended that immunotherapy be initiated during pregnancy in those who have not been taking it."

According to the committee recommendations, "inhaled corticosteroids should generally be considered the prophylactic medications of choice for use in pregnant women with persistent asthma, unless [their disease is] well-controlled by cromolyn or nedocromil." Furthermore, "if an inhaled corticosteroid is to be newly initiated in a woman who is pregnant or is likely to become pregnant, beclomethasone or budesonide should generally be chosen."

IMPORTANT CONSIDERATIONS

Dr. Schatz told PULMONARY REVIEWS that the new recommendations include two other important points. The first is that budesonide (which was not available when the previous guidelines were issued) has been added along with beclomethasone as a best-choice inhaled corticosteroid for use during pregnancy. The second is that, although beclomethasone or budesonide is recommended if an inhaled corticosteroid is started during pregnancy, a patient who is taking another inhaled corticosteroid and whose symptoms are well controlled should continue on that drug rather than switch.

Regarding the leukotriene modifiers--montelukast, zafirlukast, and zileuton--the committee recommends that zileuton not be used during pregnancy because of adverse effects in animal studies. Animal studies on zafirlukast and on montelukast have not detected problems during pregnancy; however, no human gestational data are available for any of these drugs. "While one would not generally recommend using [zafirlukast or montelukast] during pregnancy, their use could be considered in patients with recalcitrant asthma who have shown a uniquely favorable response prior to becoming pregnant," the report states.

Avoidance of oral decongestants during the first trimester of pregnancy is recommended in light of recent case-control studies that found a significant association between the use of pseudoephedrine or phenylpropanolamine and the occurrence of gastroschisis, a rare birth defect.

WEIGHING THE RISKS AND BENEFITS

"Adequately controlled asthma is associated with pregnancy outcomes not significantly different from those in women without asthma," Dr. Schatz said. The wide range of asthma and allergy medications now available requires a constant weighing of risks and benefits in designing therapy for the pregnant patient.

If asthma is not properly controlled during pregnancy, complications for the expectant mother may include high blood pressure and preeclampsia. Complications for the baby may include an increased risk of premature birth, low birth weight, and stillbirth.

"It is also important for both medical and medical-legal reasons that these general recommendations are individualized for each patient, and that informed consent is obtained and documented," the position statement concluded.

--Janis Kelly

Reference
1. Position statement: The use of newer asthma and allergy medications during pregnancy. Ann Allergy Asthma Immunol. 2000;84:475-480.

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