Has anyone experience a gradual sensitivity to this drug? I have been taking it for almost 2 years now ( i switched from atenolol). About 2 months ago I began experiencing pressure in my ears and occassional difficulty in swallowing. I was told I was snoring. Most recently I was told that I was gasping for aid while I slept (3x in one night). A few days ago I noticed my tongue was swollen. The only constant in my diet in this pill. I have gone to the ENT doctor and tests concluded that my hearing was normal and so was the pressure. No blockages in my sinuses. Years ago after taking Sulfur for chronic sinus infections I developed hives. I'm thinking that I build up an allergy after a period of time. Does anyone know if this can happen with the Metoprolol or if you have experienced this or anything similiar yourself. Thank you for your response.