Orthostatic hypotension:
Typically amiodarone does not cause orthostatic hypotension. Is your mother on any other medication which could affect her blood pressure? Her pacemaker should also be interrogated to evaluate her heart rhythm during this episode. The half life of amiodarone is very long and its effect is typically not acute.
I would discuss this further with her regular doctor.
Thanks for your question,
CCF-MD-KE