Tarceva Side Effects

I need some help regarding side effects with Tarceva.  My wife (age 36) was diagnosed with Stage IV adenocarcinoma.  After Chemo new spots appeared in her lungs.  They started her on 150mgs of Tarceva and reduced her to 100mg after the bad rash and stomache problems.  Currently her rash is manageable.  However she has a terrible cough and is always tired.  The doctor says the spots in her lungs are to small to be causing the cough on their own.  Has anyone else experienced this 'Tarceva' cough?  How about the fatigue?  How did you handle it?...