Allergists have emphasized that the drug will not be appropriate for every family. It is approved for children ages 4 to 17 and requires children to eat increasing doses of peanut protein to gradually desensitize their allergies. That means patients must intentionally expose themselves to the very substance that can cause a life-threatening reaction under the regimen, called oral immunotherapy. Due to the risks, patients must take some doses under a doctor’s supervision. The drug can cause severe allergic reactions and require epinephrine injections. It’s unclear how long patients will have to stay on the drug.