Sofosbuvir is used with other antiviral medications (such as ribavirin, peginterferon, daclatasvir) to treat chronic (long-lasting) hepatitis C, a viral infection of the liver. It works by reducing the amount of hepatitis C virus in your body, which may help your liver recover. Chronic hepatitis C infection can cause serious liver problems such as scarring (cirrhosis), or liver cancer.

Sofosbuvir in combination with other antiviral medications reduces the amount of hepatitis C virus in the body and helps the body's immune system fight the infection. It is not known if this treatment can prevent you from passing the virus to others. Do not share needles, and practice "safer sex" (including the use of latex condoms) to lower the risk of passing the virus to others.

Sofosbuvir must be used in combination treatment to have the best effect. Do not use sofosbuvir alone to treat hepatitis C.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start taking sofosbuvir and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Also read the drug information for your other antiviral medication(s).

Take this medication by mouth with or without food as directed by your doctor, usually once daily. The dosage is based on your medical condition and response to treatment. Children's dosage is also based on weight.

If you are using the pellet form of this medication, gently shake the packet before use. To take this medication without food, open the packet and pour the pellets directly into your mouth. Swallow the pellets without chewing. You may drink water after swallowing the pellets if needed. Repeat these steps if your dose is for more than one packet. If you are taking this medication with food, open the packet(s) and pour the pellets into a small bowl with one or more spoonfuls of non-acidic soft food (such as pudding, mashed potato, ice cream). The soft food should be at or below room temperature. After gently mixing, take all of the mixture without chewing within 30 minutes.

This medication works best when the amount of drug in your body is kept at a constant level. Take this drug at evenly spaced intervals. To help you remember, take it at the same time each day.

Continue to take sofosbuvir and your other antiviral medication(s) for the full length of time prescribed, even if your symptoms disappear after a short time. Stopping any of the drugs too early may result in a return of the infection.

See also Warning section.

Tiredness, headache, nausea, diarrhea, itchy skin, difficulty sleeping, or irritability may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• signs of low red blood cell count (such as unusual tiredness, rapid breathing, pale skin, shortness of breath, fast heartbeat)

A very serious allergic reaction to this drug 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.

Before taking sofosbuvir, tell your doctor or pharmacist if you are allergic to it; 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 medication, tell your doctor or pharmacist your medical history, especially of:

• kidney disease
• other liver problems (such as hepatitis B)
• diabetes

If you have diabetes, your blood sugar may be lower with hepatitis C treatment. This can increase your risk of low blood sugar, so your doctor may adjust your diabetes treatment plan. Tell your doctor right away if you have symptoms of low blood sugar such as sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, sofosbuvir should be used only when clearly needed. Sofosbuvir, in combination with ribavirin or peginterferon, must not be used during pregnancy by either the pregnant woman or her male partner. The combination may harm an unborn baby. Reliable forms of birth control must be used whenever at least one sexual partner is using these medicines together. Female patients should keep using birth control for 9 months after stopping treatment. Male patients should keep using birth control for 6 months after stopping treatment. 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 medication passes into breast milk. Consult your doctor before breastfeeding.

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.

A product that may interact with this drug is:

• amiodarone

Other medications can affect the removal of sofosbuvir from your body, which may affect how sofosbuvir works. Examples include apalutamide, rifamycins (such as rifampin, rifabutin), St. John's wort, tipranavir/ritonavir, drugs used to treat seizures (such as carbamazepine, phenobarbital, phenytoin, primidone), among others.

Do not take this medication with other products that contain sofosbuvir.

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 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab tests (such as liver function, tests for hepatitis B and C) should be done before you start using this medication, while you are using it, and after completing treatment. Keep all medical and lab appointments.

If you are using this medication with ribavirin, it is recommended that female patients or female partners of male patients take a pregnancy test before starting this medication. Pregnancy tests should continue to be done while using this medication and for some time after this medication is stopped to make sure no pregnancy occurs (for 9 months for female patients and for 6 months for female partners of male patients).

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Store the tablets in the original container. For the pellets, do not open the packets until you are ready to use the medication. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.