Zileuton is primarily used in the treatment of asthma, specifically to manage and prevent chronic symptoms. It works by inhibiting the enzyme 5-lipoxygenase, which reduces the production of leukotrienes, compounds that cause inflammation, bronchoconstriction, and increased mucus production in the airways. This makes it effective in controlling asthma attacks and improving lung function in patients with persistent asthma. It is often prescribed for individuals who do not respond adequately to other asthma medications like inhaled corticosteroids. Additionally, zileuton may be used off-label for conditions involving leukotriene-related inflammation, such as certain allergic reactions or chronic obstructive pulmonary disease (COPD). Patients typically take it orally in tablet form, and its use requires monitoring of liver function due to potential side effects.