Stalevo and asthma

Hi, my mum in law seems to be having problems which might be down to taking stalevo. She has asthma and seems to have coughing fits not long after taking stalevo, she says it's like breathing some sort of gas from her stomach. She has a hiatus hernia and sometimes has reflux. I just wondered if anyone else has had similar experiences? When she has a coughing fit she ends up not being able to breathe,rushed into hospital and placed on the chest ward only for them to find nothing causing it which is why I think it may be the stalevo as she has only just started to mention the 'gas' symptom.