 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  Your doctor should order a pregnancy test before you start this medication. Ask about reliable forms of birth control while using this medication and for 4 months after the last dose. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication. It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug and for 4 months after stopping treatment. Consult your doctor before breast-feeding.The interactions of Vandetanib Oral: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Many drugs besides vandetanib may affect the heart rhythm (QT prolongation), including amiodarone, chloroquine, disopyramide, dofetilide, granisetron, haloperidol, methadone, moxifloxacin, pimozide, procainamide, s </s>