Health Guide

Letermovir (By mouth)

Letermovir (let-ER-moe-vir)

Prevents cytomegalovirus (CMV) infection and disease.

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is generally considered safe for most people. Talk to your doctor if you have concerns.

How to Use This Medicine:


  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Swallow the tablet whole. Do not crush, break, or chew it.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Store the medicine in its original container until you are ready to use it.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use this medicine together with pimozide or ergot medicines.
  • Do not use pitavastatin or simvastatin if you take this medicine together with cyclosporine.
  • Some medicines can affect how letermovir works. Tell your doctor if you are using any of the following:
    • Alfentanil, amiodarone, fentanyl, midazolam, phenytoin, quinidine, rifampin, sirolimus, tacrolimus, voriconazole
    • Blood thinner medicine (including warfarin)
    • Medicine to lower cholesterol (including atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin)
    • Oral diabetes medicine (including glyburide, repaglinide, rosiglitazone)
    • Proton pump inhibitor (including omeprazole, pantoprazole)

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease or liver disease.
  • Do not stop taking this medicine without talking to your doctor first.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

If you notice these less serious side effects, talk with your doctor:

  • Cough
  • Diarrhea, stomach pain
  • Headache
  • Nausea, vomiting
  • Tiredness or weakness

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 7/4/2018
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