Singulair and bitter taste

my wife aged 45 yrs took montelukast 10 mg at night 2nd day she felt numbness of hands and feet and bitter taste 4th day she developed blurring of vision, haeadache, pain during chewing meals, slurred speech and vertigo then after 5th & 6th day she devoloped vomitting. she has taken only 3 tabs and today is the 5th day to stop the drug but still she is feeling nausea vomitting diplopia Double vision vertigo headache. What should I do now.

my wife aged 45 yrs took montelukast 10 mg at night 2nd day she felt numbness of hands and feet and bitter taste 4th day she developed blurring of vision, haeadache, pain during chewing meals, vertigo then after 5th & 6th day she devoloped vomitting. she has taken only 3 tabs and today is the 5th day to stop the drug but still she is feeling nausea vomitting diplopia Double vision vertigo headache. What should I do now.