Sofosbuvir belongs to the class of medications called antivirals. It is used to treat chronic infection with hepatitis C virus. Sofosbuvir is used along with ribavirin and sometimes peginterferon alfa.

Sofosbuvir works by blocking one of the steps in the reproduction of the virus, helping to stop the duplication of the virus and allowing the body to get rid of the virus. It must be used in combination with other antiviral medications to reduce the opportunity for the virus to become resistant to it.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of sofosbuvir is 400 mg (1 tablet) taken once daily. It must be taken with another antiviral medication. Your doctor will determine which other antiviral medication is most appropriate for treating you, depending on characteristics of the hepatitis C virus. If these medications must be stopped, sofosbuvir must also be stopped.

Sofosbuvir may be taken for 12 weeks to 24 weeks, depending on the other antiviral medications you are taking and your body's response to the medication.

Sofosbuvir may be taken with or without food.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor.

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

If you vomit less than 2 hours after taking a dose, you should take another tablet. If you vomit more than 2 hours after taking your dose, do not take another tablet until your next regularly scheduled dose.

Store this medication at room temperature in the original container, protect it from light and moisture, and keep it out of the reach of children.

Each yellow, capsule-shaped, film-coated tablet debossed with "GSI" on one side and "7977" on the other side contains 400 mg of sofosbuvir. Nonmedicinal ingredients: mannitol, microcrystalline cellulose, croscarmellose sodium, colloidal silicon dioxide, and magnesium stearate. Film-coating: polyvinyl alcohol, titanium dioxide, polyethylene glycol/macrogol, talc, and yellow iron oxide.

Do not take sofosbuvir if you:

• are allergic to sofosbuvir or any ingredients of the medication
• have any reason that you should not take ribavirin or interferon
• are pregnant or may become pregnant
• have a pregnant partner or a partner who may become pregnant

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• headache
• irritability
• nausea
• rash
• tiredness
• trouble sleeping

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• symptoms of very slow heart rate (e.g., dizziness, fainting, feeling unwell, shortness of breath, confusion, memory problems, chest pains, feeling weak or very tired)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Heart function: Taking sofosbuvir while taking certain medications to control heart rhythm may result in a serious decrease in the heart rate. This can cause severe heart problems, including fatal heart attack. If you have a history of heart disease or are taking medications to control blood pressure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this mediation, and whether any special monitoring is needed.

Hepatitis B reactivation: People who have hepatitis B infection that is dormant may experience the infection returning, causing further liver dysfunction or liver failure. If you have a history of hepatitis B infection, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this mediation, and whether any special monitoring is needed.

If you experience symptoms of worsening liver function, such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Pregnancy and contraception: The use of this medication is not recommended for pregnant people or people who may become pregnant, as other medications which must be taken with sofosbuvir (in particular ribavirin) may cause birth defects or the death of the fetus if it is used during pregnancy. Do not use this medication if you are pregnant or if your partner is pregnant.

Two forms of effective birth control must be used during treatment and for 6 months after stopping therapy. During this time, people who may become pregnant will have monthly pregnancy tests to ensure they are not pregnant. Tell your doctor immediately if you or your partner becomes pregnant while using this medication.

Breast-feeding: It is not known if sofosbuvir passes into breast milk. Due to the potential for serious harm to a baby if they are exposed to these medications, breast-feeding must be stopped before starting this medication.

Children: The safety and effectiveness of using this medication have not been established for children.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.