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. If a pregnancy occurs while you are using these medicines, tell your doctor right away.
To make sure you are not pregnant, your doctor may ask you to have a pregnancy test before you start using this medicine. You must have a negative pregnancy test before you will be allowed to use this medicine with ribavirin. Two forms of birth control must be used during treatment and for 6 months after treatment ends. You should test for pregnancy every month while you are using this medicine, and for 6 months after your treatment ends.
Do not use the following medicines while you are using this medicine: alfuzosin (Uroxatral®), cisapride (Propulsid®), oral midazolam (Versed®), pimozide (Orap®), rifampin (Rifadin®, Rimactane®), sildenafil (Revatio®), St. John's wort, tadalafil (Adcirca®), triazolam (Halcion®), certain medicines to lower cholesterol (such as lovastatin, simvastatin, Mevacor®, or Zocor®), or ergot medicines (such as dihydroergotamine, ergonovine, ergotamine, methylergonovine, DHE 45®, Ergomar®, Ergotrate®, or Methergine®). Using telaprevir with any of these medicines can cause very serious medical problems.
Serious allergic reactions can occur with this medicine. Stop using this medicine and check with your doctor right away if you have blistering, peeling, or loosening of the skin, fever or chills, hives or welts, red skin lesions, a severe skin rash or acne, sores or ulcers on the skin, or yellowing of the skin or the whites of your eyes.
Check with your doctor right away if you have back, leg, or stomach pains, bleeding gums, chills, dark urine, difficulty with breathing, fever, general body swelling, headache, loss of appetite, nausea or vomiting, nosebleeds, pale skin, sore throat, unusual tiredness or weakness, or yellowing of the eyes or skin. These could be symptoms of a blood disorder called anemia.
Birth control pills may not work while you are using this medicine. To keep from getting pregnant, use two other forms of birth control. Other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.
Using this medicine with peginterferon alfa can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets in the blood, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:
- If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
- Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in the urine or stools; or pinpoint red spots on your skin.
- Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
- Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
- Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
- Avoid contact sports or other situations where bruising or injury could occur.
Do not change or suddenly stop using this medicine without checking first with your doctor.
This medicine will not keep you from giving hepatitis C to other people. Follow your doctor's instructions about how to prevent the spread of this infection.
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.