SIDE EFFECTS: See also Warning section. Tiredness, weakness, nausea, mild itching, or difficulty sleeping may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this product because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this product do not have serious side effects. This product can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Therefore, tell your doctor right away if you develop any rash. A very serious allergic reaction to this product is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking this product, tell your doctor or pharmacist if you are allergic to any of the drugs; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this product, tell your doctor or pharmacist your medical history, especially of: other liver problems (such as hepatitis B), HIV infection. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). During pregnancy, this product should be used only when clearly needed. Discuss the risks and benefits with your doctor. This product, in combination with ribavirin, must not be used during pregnancy by either the pregnant woman or her male partner. The combination may harm an unborn baby. Two reliable forms of birth control (such as condoms, birth control pills) must be used whenever at least one sexual partner is using these medicines together, and for 6 months after stopping treatment (see also Drug Interactions section). If you or your partner becomes pregnant, or if you think you or your partner may be pregnant, tell your doctor right away. It is unknown if this product passes into breast milk. Breast-feeding while using this product, in combination with ribavirin, is not recommended. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: 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. Some products that may interact with this drug include: efavirenz, ethinyl estradiol-containing products (such as combined birth control pills, patch or ring). If you are using hormonal birth control containing a certain type of estrogen (ethinyl estradiol), it must be stopped before starting treatment with this product. Use other reliable forms of birth control during treatment with this product and for 2 weeks after stopping treatment. Ethinyl estradiol-containing birth control may be restarted after that time. Talk to your doctor for more details. This product can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include certain alpha blockers (such as alfuzosin, silodosin), certain benzodiazepines (midazolam, triazolam), cisapride, colchicine, ergot alkaloids (such as dihydroergotamine, ergotamine), certain heart drugs (dronedarone, ranolazine), lurasidone, pimozide, rilpivirine, salmeterol, certain drugs used to treat erectile dysfunction-ED or pulmonary hypertension (avanafil, sildenafil), certain "statin" cholesterol drugs (atorvastatin, lovastatin, simvastatin), certain drugs that weaken the immune system (such as everolimus, sirolimus, tacrolimus, temsirolimus), among others. Other medications can affect the removal of this product from your body, which may affect how this product works. Examples include certain drugs used to treat seizures (such as carbamazepine, phenobarbital, phenytoin, primidone), clopidogrel, cobicistat, gemfibrozil, mitotane, rifampin, St. John's wort, among others. Do not take this product with other products that contain ritonavir.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.