Pronunciation:

let-ER-moe-vir

Brand Names:

• Prevymis

Dosage Forms:

• Tablet

Classifications:

Therapeutic—

Antiviral

Uses of This Medicine:

Letermovir is used alone or together with another medicine (eg, cyclosporine) to prevent cytomegalovirus (CMV) infection and disease in patients who have received an allogeneic hematopoietic stem cell (bone marrow) transplant or in patients who have received kidney transplant who have a high risk for getting CMV disease.

This medicine is available only with your doctor's prescription.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies have not been performed on the relationship of age to the effects of letermovir in children. Safety and efficacy have not been established.

Older adults—

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of letermovir in the elderly.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Bromocriptine
• Dihydroergotamine
• Eliglustat
• Ergonovine
• Ergotamine
• Flibanserin
• Lomitapide
• Methylergonovine
• Methysergide
• Pimozide
• Pitavastatin
• Simvastatin

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acalabrutinib
• Alprazolam
• Amiodarone
• Aprepitant
• Atorvastatin
• Avapritinib
• Bosutinib
• Brexpiprazole
• Brigatinib
• Buprenorphine
• Cilostazol
• Clozapine
• Cobimetinib
• Codeine
• Colchicine
• Cyclosporine
• Daridorexant
• Darolutamide
• Deflazacort
• Elacestrant
• Elexacaftor
• Enasidenib
• Encorafenib
• Entrectinib
• Eplerenone
• Fexinidazole
• Finerenone
• Fosaprepitant
• Fosphenytoin
• Gepirone
• Glyburide
• Ibrutinib
• Infigratinib
• Ivabradine
• Ivacaftor
• Ivosidenib
• Larotrectinib
• Leflunomide
• Lemborexant
• Leniolisib
• Lovastatin
• Lumateperone
• Lurasidone
• Lurbinectedin
• Mavacamten
• Midazolam
• Midostaurin
• Mitapivat
• Mobocertinib
• Naloxegol
• Olaparib
• Omaveloxolone
• Oxycodone
• Pacritinib
• Palovarotene
• Pemigatinib
• Pexidartinib
• Phenytoin
• Pralsetinib
• Repaglinide
• Rifampin
• Rimegepant
• Rosiglitazone
• Selpercatinib
• Selumetinib
• Sirolimus
• Sirolimus Protein-Bound
• Sonidegib
• Sparsentan
• Tacrolimus
• Tazemetostat
• Teriflunomide
• Tezacaftor
• Tolvaptan
• Trofinetide
• Ubrogepant
• Venetoclax
• Venlafaxine
• Voclosporin
• Voriconazole
• Warfarin
• Zanubrutinib
• Zolpidem

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Amlodipine
• Eltrombopag
• Suvorexant

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Kidney disease, severe—Use with caution. May make this condition worse.

• Liver disease, severe—Use is not recommended in patients with this condition.

Proper Use of This Medicine:

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine should come with a patient information leaflet. Read and follow these instructions carefully. Ask your doctor if you have questions.

You may take this medicine with or without food.

Swallow the tablet whole. Do not crush, break, or chew it.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (tablets):
  • For prevention of CMV infection or disease in patients who have received hematopoietic stem cell transplant:
    • Adults—480 milligrams (mg) once a day, starting between Day 0 and Day 28, and continue until Day 100 after transplant.
    • Children—Use and dose must be determined by your doctor.
  • For prevention of CMV infection or disease in patients who have received kidney transplant:
    • Adults—480 milligrams (mg) once a day, starting between Day 0 and Day 7, and continue until Day 200 after transplant.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in its original container until you are ready to use it.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Do not use this medicine together with pimozide (Orap®) or ergot medicines (eg, dihydroergotamine, ergonovine, ergotamine, methylergonovine, Cafergot®, Ergomar®, Wigraine®).

Do not use pitavastatin (Livalo®) or simvastatin (Zocor®) when you take this medicine together with cyclosporine (Gengraf®, Neoral®, Sandimmune®).

Do not stop taking this medicine without asking your doctor first.

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.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Bloating or swelling of the face, arms, hands, lower legs, or feet

rapid weight gain

tingling of the hands or feet

unusual weight gain or loss

Less common

Black, tarry stools

chest pain

chills

cough

dizziness

fainting

fast, pounding, or irregular heartbeat or pulse

fever

lower back or side pain

painful or difficult urination

pale skin

sore throat

trouble breathing

ulcers, sores, or white spots in the mouth

unusual bleeding or bruising

unusual tiredness or weakness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Diarrhea

headache

nausea

stomach pain

vomiting

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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