dasabuvir, ombitasvir, paritaprevir, and ritonavir

What is the most important information I should know about this medicine?

If you have ever had hepatitis B, Viekira can cause this condition to come back or get worse. You will need frequent blood tests to check your liver function.

What is dasabuvir, ombitasvir, paritaprevir, and ritonavir (Viekira)?

Dasabuvir, ombitasvir, paritaprevir, and ritonavir (Viekira) is a combination antiviral medicine used to treat chronic hepatitis C virus (HCV) in adults. Viekira is sometimes given in combination with another antiviral medicine called ribavirin.

Viekira treats specific genotypes of hepatitis C, and only in certain people. Use only the medications prescribed for you. Do not share your medicine with other people.

Viekira is sometimes used in people who also have HIV. This medicine is not a treatment for HIV or AIDS.

Viekira may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking this medicine?

• you have moderate to severe liver disease; or
• you have ever had a severe skin rash after taking ritonavir (Norvir).

If you take Viekira with ribavirin: There may be other reasons you should not take this combination treatment. Tell your doctor about all your medical conditions.

Many drugs can interact and cause dangerous effects. Some drugs should not be used together with Viekira. Your doctor may change your treatment plan if you also use:

• alfuzosin;
• apalutamide;
• colchicine;
• dronedarone;
• efavirenz (Atripla, Sustiva, Symfi);
• ranolazine;
• rifampin;
• sildenafil (Revatio), when taken for pulmonary artery hypertension (PAH);
• St. John's wort;
• oral midazolam (Versed), or triazolam;
• anti-psychotic medicine --lurasidone, pimozide;
• birth control pills or patches --Lo Loestrin FE, Norinyl, Ortho Tri-Cyclen Lo, Ortho Evra, and others;
• hormone replacement therapy such as Fem HRT;
• a vaginal ring such as NuvaRing;
• cholesterol-lowering medicine --atorvastatin, gemfibrozil, lomitapide, lovastatin, simvastatin (Zocor, Vytorin, Simcor);
• an immunosuppressant --everolimus, sirolimus, tacrolimus;
• ergot medicine --dihydroergotamine, ergotamine, methylergonovine; or
• seizure medicine --carbamazepine, phenytoin, phenobarbital.

Tell your doctor if you have ever had:

• liver problems other than hepatitis C (such as cirrhosis or hepatitis B);
• HIV (human immunodeficiency virus);
• a liver transplant; or
• if you use a blood thinner (warfarin, Coumadin, Jantoven) and you have routine "INR" or prothrombin time tests.

You should not take ribavirin if you are pregnant, or if you are a man and your sex partner is pregnant. Use effective birth control to prevent pregnancy. Keep using birth control for at least 6 months after your last dose of ribavirin.

Tell your doctor right away if a pregnancy occurs while either the mother or the father is using ribavirin.

How should I take this medicine?

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using Viekira.

Viekira is usually taken for 12 to 24 weeks. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Viekira XR is an extended-release form of this combination medicine to be taken once daily. Viekira XR is supplied as 3 pale yellow tablets that are taken all at once with a daily meal.

The Viekira Pak contains two different types of tablets. The pink tablet contains only ombitasvir, paritaprevir, and ritonavir. The beige tablet contains only dasabuvir.

Take 2 pink tablets plus 1 beige tablet at the same time every morning. Take 1 beige tablet at the same time every evening.

The monthly Viekira XR or Viekira Pak carton contains enough tablets for you to take this medicine for 4 weeks (28 days in a row).

You will need frequent blood tests to check your liver function.

If you have ever had hepatitis B, Viekira can cause this condition to come back or get worse. You will need liver function tests during treatment and for several months after you stop using this medicine.

Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with chronic hepatitis C should remain under the care of a doctor.

What happens if I miss a dose?

If you miss a dose of the pink tablets, take the missed dose with a meal as soon as you remember. If you are more than 12 hours late, skip the missed dose and take your next dose at the usual time with a meal.

If you forget to take the beige tablet, take it with a meal as soon as you remember. If you are more than 6 hours late in taking the beige tablet, skip the missed dose and take your next dose at the usual time with a meal.

Do not take two doses at one time.

What happens if I overdose?

What should I avoid while taking this medicine?

Using this medicine will not prevent your disease from spreading. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HCV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

What are the possible side effects of this medicine?

• confusion;
• loss of appetite, upper stomach pain;
• dark urine, clay-colored stools; or
• jaundice (yellowing of the skin or eyes).

Common side effects may include:

• nausea;
• itching, skin rash or redness;
• sleep problems (insomnia); or
• feeling weak or tired.

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.

What other drugs will affect this medicine?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can interact with Viekira, and some drugs should not be used together. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide. Tell your doctor about all your current medicines and any medicine you start or stop using.

Where can I get more information?

Your pharmacist can provide more information about dasabuvir, ombitasvir, paritaprevir, and ritonavir (Viekira).