Firstly you must change position often as no medication will work without pressure care.
Do you sit on a ROHO? These are really great for preventing pressure build up, but still don't replace respositioning.
Gentle massaging around the area as well as directly over the area with your choice of creams made for pressure care or even coconut oil is great. There are honey dressings that can be used to apply if the skin is broken until this heals.
My fave is Bag Balm. It was originally made for chapped udders, it moisturizes and has a mild antiseptic so sores can heal and not become an abcess. You can get it at walmart or farm supply stores. It sounds weird but it works!