Can Brintillex And Gabapentin Cause Muscles Pain?

I recently started Brintillex for depression and Gabapentin for migraines in the last two months. My feet and thigh muscles ache and I am having a hard time walking. My hands also hurt. But I have also been under a lot of stress, so I am not sure if this started it. I have been to a Rheumatologist and all tests have been negative for arthritis. I am hyperthyroid and have been for about six months. I am also very tired. Thank you for your input. No doctor has been able to provide me with an answer, except to try physical therapy.