Is there any oral maintenance medicine fot her2 breast cancer after finishing the herceptin (trastuzumab)?

Yes: First very close follow up by the oncologist, preventing osteoporosis, zometa will help ske ( skeletal related events , like fractures joint and muscle problems ) in 40% , risk of metastasis in 14 % , speak to your oncologist.

Hormonal treatment: If the cancer is er positive then tamoxifen or an aromatase inhibitor would be beneficial to reduce the risk of recurrence.