Primatene MIST (epinephrine inhalation aerosol) contains the active ingredient epinephrine for temporary relief of mild symptoms of intermittent asthma. Primatene MIST is an over-the-counter asthma inhaler for temporary relief of mild symptoms of intermittent asthma including wheezing, tightness of chest and shortness of breath. It has 160 metered sprays and provides 0.125 mg per spray. For oral inhalation use only.