You are saying there is pain in her temple on one side that goes down her arm and to her hand?
Lowering your blood pressure as much as your meds has yours can cause you to feel light headed. Make sure you sir on edge of bed before standing then stand until you feel fine. A 150 systolic pressure is not low enough. Notify your physician as your physician may want to adjust your meds to give you a much better pressure as well as lessen your side effects, although blood pressure meds are notorious for causing one to be dizzy or light headed when changing positions to quickly. One size does not fit all. Good luck!
My mom used to get headaches in the temple and while the doctor told her they weren't an indicator of anything serious, he thought it might have to do with the fact that she had arthritis in her upper spine.