Ribasphere Ribapak

Name: Ribasphere Ribapak

Ribasphere RibaPak Overview

Ribasphere RibaPak is a prescription medication used simultaneously with another prescription medication called peginterferon alfa-2a to treat chronic hepatitis C infection in adults and in children 5 years and older. Ribasphere RibaPak belongs to a group of antiviral drugs called nucleoside analogues. These work by stopping the spread of the hepatitis C virus within the body.

This medication comes in tablet form and is usually taken twice a day, with food, for 24 or 48 weeks depending on which type of hepatitis C you have. 

Common side effects of Ribasphere RibaPak include flu-like symptoms, fatigue, and headache.

Ribasphere RibaPak can also cause drowsiness, dizziness, and/or blurred vision. Do not drive or operate heavy machinery until you know how Ribasphere RibaPak affects you.



  • Kadmon Pharmaceuticals, LLC

Ribasphere RibaPak Drug Class

Ribasphere RibaPak is part of the drug class:

  • Nucleosides and nucleotides excl. reverse transcriptase inhibitors

Side Effects of Ribasphere RibaPak

Serious side effects have been reported with Ribasphere RibaPak. See the "Ribasphere RibaPak Drug Precautions"section.

Common side effects of Ribasphere RibaPak include:

  • flu-like symptoms
  • mood changes
  • a decrease in the blood cells that fight infection (neutropenia)
  • a decrease in appetite
  • insomnia
  • anxiety
  • stomach pain and vomiting
  • hair loss
  • itching

This is not a complete list of Ribasphere RibaPak side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Ribasphere RibaPak Precautions

Serious side effects have been reported with Ribasphere RibaPak including the following:

  • birth defects. Ribasphere RibaPak may cause birth defects and/or death of exposed fetuses. Ribasphere RibaPak therapy should not be started unless a report of a negative pregnancy test has been obtained immediately prior to planned initiation of treatment. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Patients should be instructed to use at least two forms of effective contraception during treatment and for 6 months after treatment has been stopped. Pregnancy testing should occur monthly during Ribasphere RibaPak therapy and for 6 months after therapy has stopped.
  • anemia. The primary toxicity of Ribasphere RibaPak is called hemolytic anemia, which was observed in approximately 13% of all Ribasphere RibaPak-treated subjects in clinical trials. Anemia associated with Ribasphere RibaPak typically occurs within 1 to 2 weeks of initiation of therapy. Patients with pre-existing heart disease should have heart tests done before treatment, and should be appropriately monitored during therapy. If there is any deterioration of heart function, therapy should be suspended or discontinued. Because heart disease may be worsened by drug-induced anemia, patients with a history of significant or unstable heart disease should not use Ribasphere RibaPak.
  • bone marrow toxicity. Your physician will monitor your blood levels while you are taking Ribasphere RibaPak and adjust your dose if necessary.
  • neuropsychiatric disorders. Severe psychiatric problems may occur in patients receiving therapy with medications like Ribasphere RibaPak including depression, suicidal ideation, suicide attempts, psychosis, aggressive behavior, nervousness, anxiety, emotional lability, abnormal thinking, agitation, apathy and/or relapse of drug addiction. Ribasphere RibaPak should be used with extreme caution in patients who report a history of depression. Immediately report any sign or symptom of depression and/or suicidal ideation to your physician.
  • liver failure. Chronic hepatitis C (CHC) patients with cirrhosis may be at risk of liver decompensation and death when treated with Ribasphere RibaPak. During treatment, patients’ clinical status and liver function should be closely monitored for signs and symptoms of liver decompensation. 
  • acute hypersensitivity reactions. Serious acute hypersensitivity reactions have been reported in rare instances following treatment with medications similar to Ribasphere RibaPak. Ribasphere RibaPak should be discontinued immediately and appropriate medical treatment instituted if you experience the following symptoms
  • swelling of the lips or mouth
  • difficulty breathing
  • hives

Do not take Ribasphere RibaPak if you:

  • are pregnant
  • are a man whose female partner is pregnant
  • have thalassemia major or sickle-cell anemia
  • have autoimmune hepatitis
  • have hepatic decompensation

Ribasphere RibaPak can also cause drowsiness, dizziness, and/or blurred vision. Do not drive or operate heavy machinery until you know how Ribasphere RibaPak affects you.

Ribasphere RibaPak Food Interactions

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Ribasphere RibaPak, there are no specific foods that you must exclude from your diet when receiving this medication.

Take Ribasphere RibaPak with food.

Ribasphere RibaPak and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Ribasphere RibaPak falls into category X. It has been shown that women taking Ribasphere RibaPak during pregnancy may have babies born with problems. There are no situations where the benefits of the medication for the mother outweigh the risks of harm to the baby. These medicines should never be used by pregnant women.

Ribasphere RibaPak and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if Ribasphere RibaPak crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using Ribasphere RibaPak.

Commonly used brand name(s)

In the U.S.

  • Copegus
  • Rebetol
  • RibaPak
  • Ribasphere
  • Ribasphere Ribapak
  • RibaTab

Available Dosage Forms:

  • Tablet
  • Solution
  • Capsule

Therapeutic Class: Antiviral

Pharmacologic Class: Viral RNA Polymerase Inhibitor

Chemical Class: Guanosine Nucleoside Analog