Can Taking Revelol For Long Time For Hypertension Cause Any Side Effects?

I am 52 year old Male. 182 cm height & 79 kg. weight and generally healthy.During PFT my breathing capacity was found to be 52%. I was feeling breathlessness at times and doctor said this need to be immediately attended to and from April 2014 I started taking medcines - Symbicort turbohaler 1 puff daily morning & evening, Unicontin 400 & Neksium 20 mg. If I dont take it my throat become choked and cough will start.I had mild hypertension in 2010 and am taking Revelol AM25/2.5 one tablet daily morning since 2010 & is continuing.Till April 2013 tests my PFT was found to be normal. Some change happened during April 2013 & April 2014.Can taking Revelol Am25/2.5 for a long time have any side effects.?The last test of PFT done in March 2015 showed my FVCex 56%pre & 51% post Asthalin in take.After Asthalin in take it reduced instead of increasing.Is there anything alarming? Do I need to go for more tests & consultations?Is this condition life threatening or life reducing?