Modalert 200, which includes modafinil, is usually safe and well-tolerated. Like any drug, it can have negative effects. Breathlessness is a common but dangerous adverse effect that should be reported to a doctor.
Since modafinil affects neurons in the brain to increase wakefulness and alertness, it might adversely impair respiratory performing in sensitive people. People with asthma or COPD are more sensitive to have this impact.
If you have breathing problems, tightness in the chest, or wheezing after taking Modalert 200, inform a healthcare provider. Before using modafinil, discuss any medical concerns with your doctor to ensure safety.