It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.
Using this medicine together with ribavirin while you are pregnant can harm your unborn baby. These medicines may also cause birth defects if the father is using it when his sexual partner becomes pregnant. Avoid pregnancy during combination treatment with this medicine and ribavirin for 6 months of stopping treatment. If a pregnancy occurs while you are using these medicines, tell your doctor right away.
Do not use the following medicines while you are using this medicine: alfuzosin (Uroxatral®), cisapride (Propulsid®), colchicine (Colcrys®), dronedarone (Multaq®), efavirenz (Sustiva®), ethinyl estradiol (Norinyl®, Ortho Evra®), everolimus (Afinitor®), gemfibrozil (Lopid®), lurasidone (Latuda®), oral midazolam (Versed®), pimozide (Orap®), ranolazine (Ranexa®), rifampin (Rifadin®, Rimactane®), sildenafil (Revatio®), sirolimus (Rapamune®), St. John's wort, tacrolimus (Prograf®), triazolam (Halcion®), certain medicines to lower cholesterol (such as atorvastatin, lovastatin, simvastatin, Mevacor®, Zocor®), medicine to treat seizures (such as carbamazepine, phenobarbital, phenytoin, Tegretol®), or ergot medicines (such as dihydroergotamine, ergonovine, ergotamine, methylergonovine, Cafergot®, Ergomar®, Wigraine®). Using Viekira Pak® with any of these medicines can cause very serious medical problems.
Check with your doctor right away if you are weak or tired, have onset of confusion, have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.