What medication is commonly used both as a controller and rescue medication for asthma?

In the management of asthma, systemic steroids are effective for rapid control of inflammation and for managing acute asthma exacerbations. They are often used in conjunction with other medications to stabilize the condition and provide immediate relief. Their anti-inflammatory properties make them suitable for addressing severe episodes of asthma, but they are not typically used as maintenance therapy due to their potential side effects when used long-term.

Inhaled corticosteroids are primarily used as controller medications to manage chronic asthma symptoms by reducing inflammation and preventing exacerbations, rather than for immediate relief during an acute attack. Long-acting beta agonists are also used as controller medications to provide prolonged bronchodilation but are not suitable for immediate rescue in an asthma attack. Anticholinergics are primarily bronchodilators, but they do not address inflammation sufficiently to be considered an optimal rescue medication.

Therefore, systemic steroids uniquely fulfill the role of managing both ongoing asthma control, particularly in severe cases, as well as providing immediate relief during an acute exacerbation, making them effective for both purposes in the context given.