Pharmacologic class (EPC) · 3 drug pages

Pyrophosphate analog DNA polymerase inhibitor: adverse event reports filed with FDA

2,514 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.

2,514
reports across the class: 0% of all reports; 162
reports, 12 months to June 2026: 210 in the 12 months before; 98%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

Pyrophosphate analog DNA polymerase inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 2,514 adverse event reports received by FDA, 0% of the database, from January 2004 to June 2026.

162 reports arrived in the 12 months to June 2026, down 23% from 210 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 98% of the class's reports are marked serious, 30.2% record death among the outcomes and 32.4% record hospitalisation, as reported.

Across the class the reactions recorded most often are off label use (25.9%), drug ineffective (15.7%) and drug resistance (13.6%). 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
FoscarnetFoscarnet sodium	brand	1,087	91	98.7%	Drug ineffective
FoscavirFoscarnet sodium	brand	779	24	97.7%	Off label use
Foscarnet sodium	generic	648	47	97.2%	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 label25.9%652
Drug ineffectivethe medicine did not work as expected15.7%394
Drug resistance13.6%341
Acute kidney injurysudden loss of kidney function10.8%271
Cytomegalovirus infection8.6%216
Renal impairmentreduced kidney function8.2%207
Nephropathy toxic8%200
Pathogen resistance7.8%197
Pancytopenialow counts of all blood cells7.5%189
Cytomegalovirus infection reactivation6.9%174
Cytomegalovirus viraemia6.6%167
Encephalitis cytomegalovirus4.9%124
Myelosuppression4.8%120
Neutropenialow neutrophils, a type of white blood cell4.3%108
Product use in unapproved indicationused for a purpose not on the label3.9%99
Renal failurekidney failure3.8%96
BK virus infection3.7%94
Condition aggravatedthe condition being treated got worse3.7%93
Product use issuea problem in how the product was used3.6%91
Cystitis haemorrhagic3.6%90
Multiple organ dysfunction syndromeseveral organs failing3.3%82
Respiratory distressdifficulty breathing3.1%79
Hypokalaemialow blood potassium2.9%73
Pyrexiafever2.5%64
Generalised oedema2.5%63

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death30.2%758

Life-threatening12%301

Hospitalisation (initial or prolonged)32.4%814

Disability2.3%58

Congenital anomaly0.2%6

Other serious72.2%1,816

Not serious2%50

Patient age

Under 22.7%69

2 to 118%200

12 to 174%101

18 to 4425.7%647

45 to 6428.9%726

65 to 748.6%215

75 and over3.1%78

Age not given19%478

Who reported

Physician35.6%894

Pharmacist6.1%153

Other health professional47.9%1,205

Lawyer0%0

Consumer or non-health professional6.1%154

Not given4.3%108

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 Pyrophosphate analog DNA polymerase inhibitor reports

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

Foscarnet, Foscavir and Foscarnet sodium. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

2,514 reports through June 2026, 162 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 (25.9%), drug ineffective (15.7%), drug resistance (13.6%), acute kidney injury (10.8%) and cytomegalovirus infection (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.