Prescription medicine
Letermovir Brand names: Prevymis
Letermovir (Prevymis) is a prescription medicine with an FDA approval on record since 2017. No generic is listed in FDA's NDC Directory.
- No generic listed
Check it at the source: the letermovir FDA label on DailyMed (effective January 14, 2026, Merck Sharp & Dohme LLC); the NDA 209940 record on Drugs@FDA; every letermovir label on DailyMed.
Highlights of the record
FDA label of January 14, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
Used for
From the label: indications and usagePREVYMIS is a CMV DNA terminase complex inhibitor indicated for: Prophylaxis of cytomegalovirus (CMV) infection and disease in adult and pediatric patients 6 months of age and older and weighing at least 6 kg who are CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant (HSCT).
Forms and strengths
- 20 mg
- 120 mg
- 240 mg
- 480 mg
- 20 mg/ml
Film-coated tablet; injection (solution); pellet.
On the market
- Earliest approval on file
- November 8, 2017 Prevymis, Merck Sharp Dohme; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- No generic approved
- Labelers listed (NDC)
- 1 of which 0 under generic applications, 1 under brand applications, repackagers included
- Last listed patent
- January 18, 2029 Prevymis tablets; not a generic launch date
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 3,121 through July 30, 2026
What is letermovir used for?
From the label: indications and usagePREVYMIS is a CMV DNA terminase complex inhibitor indicated for: Prophylaxis of cytomegalovirus (CMV) infection and disease in adult and pediatric patients 6 months of age and older and weighing at least 6 kg who are CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant (HSCT). ( 1.1 ) Prophylaxis of CMV disease in adult and pediatric patients 12 years of age and older and weighing at least 40 kg who are kidney transplant recipients at high risk (Donor CMV seropositive/Recipient CMV seronegative [D+/R-]). […]
FDA pharmacologic class: Cytomegalovirus DNA Terminase Complex Inhibitor.
Source: FDA drug label (PREVYMIS), Merck Sharp & Dohme LLC, effective January 14, 2026 (SPL set 1b49df80-be4f-47e0-a0b7-123f3e69395b), via openFDA; the full label on DailyMed
Is there a generic for letermovir (Prevymis)?
No generic letermovir is approved (Drugs@FDA, October 8, 2026). Drugs@FDA also holds 1 tentative approval: the FDA found the generic approvable, but patents or exclusivity keep it from final approval for now.
The Orange Book lists 1 patent for Prevymis tablets: the compound patent runs to January 18, 2029; a patent listed only for Prevymis injection runs to February 28, 2033. A patent or exclusivity date is not the date a generic goes on sale: court cases and settlements move it either way.
- 2017 earliest approval on file
- 2029 last listed patent
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What does the letermovir label say about other medicines?
The letermovir label names 42 other medicines in its interaction, contraindication or warning sections. The labels of 5 other medicines name letermovir. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Acyclovir | drug interactions | Drugs without Clinically Significant Interactions with PREVYMIS No clinically significant interactions were observed in adult clinical drug-drug interaction studies of letermovir and acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Amiodarone | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: amiodarone; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ amiodarone; Clinical Comments: Close clinical monitoring for adverse events related to amiodarone is recommended during co-administration. … |
| Atorvastatin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: atorvastatin; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ atorvastatin; Clinical Comments: When PREVYMIS is co-administered with atorvastatin, do not exceed an atorvastatin dosage of 20 mg daily. … |
| Bosentan | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: bosentan; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; Clinical Comments: Co-administration of PREVYMIS and bosentan is not recommended due to potential for loss of efficacy of PREVYMIS. |
| Carbamazepine | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: carbamazepine; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; Clinical Comments: Co-administration of PREVYMIS and carbamazepine is not recommended due to potential for loss of efficacy of PREVYMIS. |
| Cyclosporine | contraindications | PREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine. |
| Digoxin | drug interactions | Drugs without Clinically Significant Interactions with PREVYMIS No clinically significant interactions were observed in adult clinical drug-drug interaction studies of letermovir and acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Dihydroergotamine | contraindications | Ergot alkaloids: Concomitant administration of PREVYMIS in patients receiving ergot alkaloids may result in increased concentrations of ergot alkaloids (ergotamine and dihydroergotamine) due to inhibition of CYP3A by letermovir, which may lead to ergotism [see Warnings and Precautions (5.1) and Drug Interactions (7.2 … |
| Efavirenz | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: efavirenz; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; Clinical Comments: Co-administration of PREVYMIS and efavirenz is not recommended due to potential for loss of efficacy of PREVYMIS. |
| Ergotamine | contraindications | Ergot alkaloids: Concomitant administration of PREVYMIS in patients receiving ergot alkaloids may result in increased concentrations of ergot alkaloids (ergotamine and dihydroergotamine) due to inhibition of CYP3A by letermovir, which may lead to ergotism [see Warnings and Precautions (5.1) and Drug Interactions (7.2 … |
| Etravirine | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: etravirine; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; Clinical Comments: Co-administration of PREVYMIS and etravirine is not recommended due to potential for loss of efficacy of PREVYMIS. |
| Fentanyl | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: alfentanil, fentanyl, midazolam, and quinidine; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ CYP3A substrate; Clinical Comments: When PREVYMIS is co-administered with a CYP3A substrate, refer to the prescribing information for dosing of the … |
| Fluconazole | drug interactions | Drugs without Clinically Significant Interactions with PREVYMIS No clinically significant interactions were observed in adult clinical drug-drug interaction studies of letermovir and acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Fluvastatin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: fluvastatin, lovastatin, pravastatin, rosuvastatin; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ HMG-CoA reductase inhibitors; Clinical Comments: When PREVYMIS is co-administered with these statins, a statin dosage reduction may be necessary. … |
Every other medicine the letermovir label names
| Medicine named | Section | What the label says |
|---|---|---|
| Glyburide | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: glyburide, repaglinide, rosiglitazone; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ glyburide ↑ repaglinide ↑ … |
| Itraconazole | drug interactions | … letermovir and acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Levonorgestrel | drug interactions | … mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Lovastatin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: fluvastatin, lovastatin, pravastatin, rosuvastatin; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ HMG-CoA reductase inhibitors; … |
| Midazolam | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: alfentanil, fentanyl, midazolam, and quinidine; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ CYP3A substrate; … |
| Modafinil | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: modafinil; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Mycophenolate mofetil | drug interactions | … drug-drug interaction studies of letermovir and acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Nafcillin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: nafcillin; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Nevirapine | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: nevirapine; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Omeprazole | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: omeprazole; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ omeprazole; … |
| Pantoprazole | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: pantoprazole; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ pantoprazole; … |
| Phenobarbital | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: phenobarbital; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Phenytoin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: phenytoin; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir ↓ phenytoin; … |
| Pimozide | contraindications | CONTRAINDICATIONS PREVYMIS is contraindicated in patients receiving pimozide or ergot alkaloids: |
| Pitavastatin | contraindications | PREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine. |
| Posaconazole | drug interactions | … acyclovir, digoxin, mycophenolate mofetil, fluconazole, itraconazole, posaconazole, ethinyl estradiol, and levonorgestrel. |
| Pravastatin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: fluvastatin, lovastatin, pravastatin, rosuvastatin; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ HMG-CoA reductase inhibitors; … |
| Quinidine | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: alfentanil, fentanyl, midazolam, and quinidine; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ CYP3A substrate; … |
| Repaglinide | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: glyburide, repaglinide, rosiglitazone; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ glyburide ↑ repaglinide ↑ … |
| Rifabutin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: rifabutin; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Rifampin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: rifampin; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Rosuvastatin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: fluvastatin, lovastatin, pravastatin, rosuvastatin; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ HMG-CoA reductase inhibitors; … |
| Simvastatin | contraindications | PREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine. |
| Sirolimus | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: sirolimus; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ sirolimus; … |
| Tacrolimus | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: tacrolimus; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ tacrolimus; … |
| Thioridazine | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: thioridazine; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; … |
| Voriconazole | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: voriconazole These interactions have been studied [see ].; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ voriconazole; … |
| Warfarin | drug interactions | Concomitant Drug Class and/or Clearance Pathway/Drug Name: warfarin; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ warfarin; … |
Source: FDA drug label (PREVYMIS), Merck Sharp & Dohme LLC, effective January 14, 2026 (SPL set 1b49df80-be4f-47e0-a0b7-123f3e69395b), via openFDA; the full label on DailyMed
What do FAERS reports show for letermovir?
The FDA Adverse Event Reporting System holds 3,121 reports that list letermovir among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 580 are coded as a death and 1,223 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What next?
- Letermovir side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other