The payments and interest (if any) is not deductible.
According to the IRS:
"Loans from the following sources aren't qualified student loans.
•A related person.
•A qualified employer plan."
The education expenses you paid for with these loans would be treated as paid by you and claimed for a possible education credit on your (or the person that claimed you) tax return. The expenses would be claimed the year they were paid.
If you paid in 2017, but did not claim the expenses on your 2017 tax return, you may consider filing an amended 2017 return.