<p>Pregnancy category D. Based on its mechanism of action, Erlotinib can cause fetal harm when administered to a pregnant woman. It is not known whether Erlotinib is present in human milk. Because many drugs are present in human milk and because of the potential for serious adverse reactions in nursing infants from Erlotinib, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.</p>