Get emergency medical help if you have signs of an allergic reaction to lenvatinib: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Some people taking lenvatinib have developed a perforation (a hole or tear) or a fistula (an abnormal passageway) within the stomach or intestines. Call your doctor if you have severe stomach pain, or if you feel like you are choking and gagging when you eat or drink.
Also call your doctor at once if you have:
severe diarrhea;
headache, confusion, change in mental status, vision loss, seizure (convulsions);
little or no urination;
unusual bleeding (nosebleeds, heavy menstrual bleeding), or any other bleeding that will not stop;
severe headache, blurred vision, pounding in your neck or ears;
jaw pain or numbness, red or swollen gums, loose teeth, or slow healing after dental work;
signs of stomach bleeding - bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
heart problems - chest pain, pain in your jaw or shoulder, swelling, rapid weight gain, feeling short of breath;
signs of a blood clot - sudden numbness or weakness, problems with vision or speech;
liver problems - dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
low calcium level - muscle spasms or contractions, numbness or tingly feeling (around your mouth, or in your fingers and toes).
Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.
Common lenvatinib side effects may include:
bleeding;
stomach pain, nausea, vomiting, diarrhea;
loss of appetite, weight loss;
abnormal thyroid function tests;
muscle or joint pain;
swelling in your arms and legs;
mouth sores;
rash;
redness, itching, or peeling skin on your hands or feet;
headache, tiredness; or
cough, trouble breathing, hoarse voice.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Lenvatinib side effects (more detail)
