I read your question carefully and I understand your concern. Hifenac is a painkiller and also an antiinflammatory drug, efficient in these pains caused by arthritis as in your case. It doesn t alter the course of the disease though, just relieves the symptoms and long term regular use carries the risk of high blood pressure, gastric ulcer, kidney damage, so its use should be limited as much as possible, only when really necessary. I am afraid I am not much familiar with yoga so I can t express an opinion on the last part of your question, perhaps if you make a separate question on that regard one of my colleagues will answer. I hope to have been of help.