Long-Term Control Medicine There's a reason for this medicine's name: If your doctor prescribed it for your asthma, you need to take it every day, over a long period of time, to control the condition. Long-term control medicines are sometimes also called controller or maintenance medicines. Long-term control medicine works slowly over time to keep the airways in the lungs open and clear. It may take days or weeks for long-term control medicine to start working and keep the airways from becoming swollen and narrow. That's why people need to take it each day, even when they feel OK. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.