Interstitial Lung Disease/Pneumonitis
Lapatinib has been associated with interstitial lung disease and pneumonitis in monotherapy or in combination with other chemotherapies [see Adverse Reactions (6.1)]. Patients should be monitored for pulmonary symptoms indicative of interstitial lung disease or pneumonitis. Tykerb should be discontinued in patients who experience pulmonary symptoms indicative of interstitial lung disease/pneumonitis which are ≥Grade 3 (NCI CTCAE)
http://www.drugs.com/pro/tykerb.html