Contact Registrants will be sent an email invitation describing the study. A unique link will be generated for each registrant and included in the email invitation. After 2 weeks, a second email invitation will be sent to the registrants who have not yet participated. After 1 month, a third email invitation will be sent to the registrants who have not yet participated. We may send additional emails periodically (e.g. every 6-12 months) to subjects enrolled to remind them to complete new surveys if they have taken any other medications of interest or have experienced any new reactions/attacks.
If the registrant wants to participate in the study, he/she will follow the survey link in the email invitation, which directs him/her to an IRB-approved online consent form. If the participant consents to participate, he/she will be directed to online forms to report general information (ex. age, sex, test results, family history), suspected medication-related acute attacks, and "uneventful use of possibly risky medication". If a patient has multiple medication-related acute attacks, the patient/caregiver will be able to submit multiple report forms that will be linked. In addition to the report forms, patients will be asked to review a list of "Medications of Interest" and report current or past use.