Dycerin (diacerein) is not approved for use in major countries such as United States, Britain, Australia, etc. Hence there has been no research on its side effects when used over prolonged periods. However it is known that it is metabolised in the liver. Hence it would be advisable to periodically do LFTs (liver function tests). You have not given details of other medicines used in the past; hence I am unable to comment on alternative therapies.