Get emergency medical help if you have signs of an allergic reaction to Epclusa: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have new or worsening symptoms such as:
loss of appetite, upper stomach pain;
dark urine, clay-colored stools; or
jaundice (yellowing of the skin or eyes).
If you also take a heart rhythm medicine called amiodarone: Taking amiodarone with sofosbuvir and velpatasvir can cause dangerous side effects on your heart. Get medical help right away if you take these medicines and you have:
very slow heartbeats, chest pain, shortness of breath;
confusion, memory problems; or
weakness, extreme tiredness, light-headed feeling (like you might pass out).
Common Epclusa side effects may include:
headache;
tiredness;
nausea, diarrhea; or
sleep problems (insomnia).
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.
 Epclusa side effects (more detail)
