In its latest Drug Safety Update, the agency highlights a review of data on inhaled and intranasal corticosteroids.
The review suggests that, in addition to the known systemic effects of these drugs, a range of psychological or behavioural effect may also occur.
These effects include psychomotor hyperactivity, sleep disorders, anxiety, depression and aggression, particularly in children.
The MHRA says patients should be informed of the benefits of steroid treatment and advised of these safety issues.
In 2007, the MHRA wrote to healthcare professionals to remind them of the psychiatric side effects that can occur with systemic steroids.
The Drug Safety Update also includes a reminder on the appropriate use of long-acting beta agonists.