Pharmacologic class (EPC) · 5 drug pages

Cytomegalovirus nucleoside analog DNA polymerase inhibitor: adverse event reports filed with FDA

14,000 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

14,000
reports across the class: 0.1% of all reports; 1,086
reports, 12 months to June 2026: 1,437 in the 12 months before; 94.2%
marked serious by the reporter: 57.4% across all reports; 5
drugs with a page: brand and generic names counted separately

Cytomegalovirus nucleoside analog DNA polymerase inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 5 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 14,000 adverse event reports received by FDA, 0.1% of the database, from January 2004 to June 2026.

1,086 reports arrived in the 12 months to June 2026, down 24% from 1,437 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 94.2% of the class's reports are marked serious, 23.1% record death among the outcomes and 37.9% record hospitalisation, as reported.

Across the class the reactions recorded most often are off label use (23.2%), drug ineffective (14.4%) and cytomegalovirus infection (13.5%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Valganciclovir	generic	5,249	479	96%	Off label use
Ganciclovir	generic	4,729	339	97.9%	Off label use
ValcyteValganciclovir	brand	2,312	23	80.1%	Off label use
Valganciclovir hydrochloride	generic	1,142	159	97.2%	Off label use
Ganciclovir sodium	generic	568	86	96.5%	Off label use

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Off label useused for a purpose or in a way not on the label23.2%3,244
Drug ineffectivethe medicine did not work as expected14.4%2,010
Cytomegalovirus infection13.5%1,885
Neutropenialow neutrophils, a type of white blood cell9%1,262
Drug resistance8.6%1,207
Pancytopenialow counts of all blood cells6.4%900
Leukopenialow white blood cells5.9%831
Cytomegalovirus viraemia5.4%760
Cytomegalovirus infection reactivation5%695
Product use in unapproved indicationused for a purpose not on the label4.8%674
Thrombocytopenialow platelets4.1%580
Deaththe patient died; cause not stated by this term4.1%579
Pathogen resistance4%561
Acute kidney injurysudden loss of kidney function3.9%547
Pyrexiafever3.6%505
Diarrhoealoose or frequent stools3.4%474
Intentional product use issuedeliberate use not as intended3.2%446
Renal impairmentreduced kidney function3.1%427
Myelosuppression3%419
Anaemialow red blood cells3%416
Pneumonialung infection2.9%407
Product use issuea problem in how the product was used2.7%383
Condition aggravatedthe condition being treated got worse2.6%370
Sepsisa severe body-wide response to infection2.6%361
Nephropathy toxic2.4%330

Solid bar: share of all class reports. Hollow bar: the median share across the 5 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death23.1%3,240

Life-threatening7.5%1,046

Hospitalisation (initial or prolonged)37.9%5,305

Disability1.3%188

Congenital anomaly0.6%87

Other serious67.2%9,406

Not serious5.9%819

Patient age

Under 24.2%586

2 to 114.9%686

12 to 173.2%442

18 to 4417.6%2,462

45 to 6427.5%3,847

65 to 7410.9%1,530

75 and over3.3%468

Age not given28.4%3,979

Who reported

Physician31.3%4,379

Pharmacist5.6%782

Other health professional50.2%7,026

Lawyer0%2

Consumer or non-health professional11.8%1,652

Not given1.1%159

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Cytomegalovirus nucleoside analog DNA polymerase inhibitor reports

Which drugs are in the Cytomegalovirus nucleoside analog DNA polymerase inhibitor class on this site?

Valganciclovir, Ganciclovir, Valcyte, Valganciclovir hydrochloride and Ganciclovir sodium. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

14,000 reports through June 2026, 1,086 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

off label use (23.2%), drug ineffective (14.4%), cytomegalovirus infection (13.5%), neutropenia (9%) and drug resistance (8.6%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.