25M Americans with asthma + 16M with COPD rely on albuterol — GoodRx #14 most prescribed. Complete 2026 guide: beta-2 receptor mechanism, 9-step correct pMDI technique (70–90% of users make errors), why using it more than twice a week signals uncontrolled disease, MAOI life-threatening interaction, non-selective beta-blocker danger, GINA 2023 Airsupra update, nebulizer shortage 2026 status, and when NO relief in 20 minutes = call 911.