Doctor, I Am 70, Retired, Weight 70 Kg, Had Bye-pass

Doctor, I am 70, retired, weight 70 Kg, had bye-pass surgery in 1997 Feb, no further problems yet, visits Cardiologist every 3 months, recommended to take 1) Nitrocontin both in morning and evening, again morning Betaloc-50 mg, stamlo 2.5, Telma-H and Deplat-A after lunch, evening again 1 Betaloc-50, Stamlo 2.5 and Extor-10, daily. Now I felt some pain on my left knee, actually I have been feeling this 4-5 years back and now it has aggravated slightly and applied creams like Dynapar Gel (alpha linolenic acid and diclofenac diehylamine, methyl salicylate and menthol gel), this gives great relief or the world famous UK Radian Massage cream. Y'day a friend of mine who had the very same symptoms suggested to use Kerotol Gel (Ketorolac tromethamine Gel 2%). I applied it twice today. On a reading of its use and application etc., I found it is mainly used for eye pain and no mention is made on knee pain. Is it safe to use it. This medicine was genuinely prescribed to my friend by a known Orthopaedic Surgeon whom I also know very well. So I have full confidence on this Surgeon. Is it safe to apply it further or does it have any reaction on my system. If not advisable, I shall stop it forthwith and go ahead with my above said gel and Radian etc. Hope I shall get a reply if it is convenient to the team. Thanks. R.M. Nair