My Mother Is On Warfarin, Has A Pacemaker, Is On

My mother is on warfarin, has a pacemaker, is on blood pressure meds and recently had an blation procedure. The tubes down her throat exacerbated a persistent dry cough she has and she was seeking a cough medication that didn't interact with her meds. The pharmacist recommended Delsym. Do you consider this a safe medication for someone like her? She is having a hard time sleeping due to the cough and needs to in order to recover from her recent procedure.