You need an inhaler, if you are having an asthma attack. Bottom line. Get one! If you can't afford one, tell your Doctor. If he does not help you, find a new Doctor. Just do it NOW. OK?
i dont think there is anything you can buy or use from a pharmacy. If you have an attack and you dont have your inhaler you should go straight to the hospital
Along with that more important thing is stay away from the triggering factors like excess dust, smoke and pollens etc. For more information consult your doctor. Take care and regards.