Allergenic foods can hide in unexpected places. In fact, a search through your medicine cabinet might uncover products made with milk, egg, wheat or soy. But do highly refined drug ingredients, such as the lactose powder used in some asthma inhalers, represent a threat to individuals with food allergies?
Food-derived ingredients are used in many drug formulations as excipients—inactive ingredients that make the active ingredients easier to produce, store, administer or absorb. Most excipients are purified fats or sugars that are free of protein and therefore do not provoke IgE-mediated allergic reactions.
However, on rare occasions, allergic reactions have been triggered by protein impurities in an excipient. For example, some dry powder inhalers (DPIs) used to treat respiratory conditions such as asthma deliver lactose (milk sugar) into the lungs. The lactose can contain traces of milk protein. Although very infrequent, allergic reactions to lactose-containing DPIs have been reported in patients with milk allergies, resulting in respiratory symptoms or anaphylaxis. Some doctors recommend that asthma patients with milk allergy use metered-dose inhalers, which do not contain lactose. This is a very rare event, and most patients with milk allergy can take medical lactose without any issues or concerns.
A small number of medicines are made with whole foods rather than refined food products. These include vaccines that are grown in eggs and contain egg protein, such as the yellow fever vaccine. If someone with severe egg allergy must be immunized against yellow fever, skin testing with the vaccine can be used to assess reactivity. If the skin test is positive, the vaccine can still be given in gradually escalating doses under the supervision of a doctor experienced in recognizing and treating anaphylaxis.
Flu vaccines produced in eggs contain minute amounts of egg protein. However, these flu vaccines are considered safe for individuals with egg allergies, including those who have serious reactions to egg. Centers for Disease Control and Prevention guidelines recommend that egg-allergic individuals be observed by a doctor with anaphylaxis management experience for 30 minutes after receiving egg-grown flu vaccine. Egg-free flu vaccines are available for adults.
The measles-mumps-rubella (MMR) vaccine is grown in chick embryo cell cultures rather than in eggs. Egg-allergic individuals can receive the MMR vaccine without prior skin testing or subsequent observation.
Additional information on this topic can be found here. FARE reminds consumers the importance of reading every label, every time, including the product inserts that accompany medications. Ask your allergist if you have concerns about the risk of food allergens in medications, where labeling is not consistent with the directives of the Food Allergen Labeling & Consumer Protection Act (FALCPA).