hyperactive after taking inhaler

hi,

has anyone with a child with asthma experienced them becoming quite hyperactive, and agitated after taking sameterol ( serevent) inhaler. our 5yr old takes a variety of meds for brittle asthma but he is unable to get to sleep and is over active after taking this inhaler thats recently been prescribed.its a shame as its really helped his breathing and he has been less breathless whilst on it but the behaviour is becoming a problem both at home and at school.we have tried stopping the inhaler, his behaviour returned to normal but his breathing became worse.

we have been offered formoterol as a possible alternative cut we are not sure if that would have the same effects.

any info greatly appreciated please.