Thanks for posting your query.
Your father might suffering from degenerative arthritis
of lower back.
Your doctor had started glucosamine
which plays a role in the promotion and maintainance of the structure and function of cartilage
in the joints of the body. It improves joint function and retards progression of osteoarthritis
It is safe to be used. you can take this as advised by your doctor.
Wishing you good health
Dr Saurabh Gupta