COVERSYL

My mum has been taking Coversyl now for a year and a half. She always did have some cough but now after a year and a half of taking the medication she is experiencing chronic cough and dryness and find at times cannot even speak or continue a conversation because she is coughing so much.  The only time she is not coughing is when she is lying in bed.  The last three weeks her voice hardly comes out and she is hoarse and we are extremely concerned about her condition.  Her doctor says that it is a side effect but her condition is getting bad. She has stopped going out and refuses to socilaize because she coughs so much that she gets embarrassed and does not want any one to feel awkward around her.
What should we do? We are very concerned and worried.