VIAGRA consists of sildenafil, which is similar drugs present in One more drug called REVATIO. REVATIO is used to take care of a unusual condition named pulmonary arterial hypertension (PAH).Thu?c Kamagra 50mg hay Kamagra 100mg ch?a ho?t ch?t sildenafil theo hàm l??ng t??ng ?ng, thu?c nhóm thu?c ???c g?i là ch?t ?c ch? phosphodiesterase lo?i fiv