On the drug info sheet for Paxil, I pasted below a little snipet that is the possible adverse reactions concerning the respiratory system...note hyperventilation and asthma. Also, another listed effect, here is the definition of dyspnea:
dyspnea (dysp·nea) (disp˘ne-[schwa]) [dys- + -pnea] breathlessness or shortness of breath; difficult or labored breathing.
Respiratory:
Frequent: Cough increased, rhinitis. Infrequent: Asthma, bronchitis, dyspnea, epistaxis, hyperventilation, pneumonia, respiratory flu, sinusitis. Rare: Hiccup, lung fibrosis, sputum increased, voice alteration.