hi good evening my age is 38 and my blood pressure is 130/90,and i have blood pressure since 6 years,iam using betablockers tablets (nebicard -sm) ,while using this tablets i consider that my sex is becoming weak ,(like erection ,penis size,and ejaculation ) pls suggest me shall ,can i take the viagra or some slidenafall tablets or shall i change the nebicard sm pls suggest me thanks very much sir