Acyclovir sodium adverse event reports that FDA received

Name: Reaction terms in FDA adverse event reports that name Acyclovir sodium
Creator: Reported Reactions
License: https://creativecommons.org/publicdomain/zero/1.0/

Name type: Generic name
Class: Herpes simplex virus nucleoside analog DNA polymerase inhibitor
Also reported as: Acyclovir Sodium Injection

What a report is

A report is not proof that the drug was the cause of the event.

FDA says:

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.
Source: openFDA, Drug Adverse Event Overview, section "Responsible use of the data". The site read the page on 2 Oct 2026. The data have the reports that FDA received through 30 Jun 2026.

FDA also says:

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 has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

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.
Source: openFDA, Response of the drug event API (meta.disclaimer). The site read the page on 2 Oct 2026.

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

Reports on file

From January 2004 to May 2026, FDA received 407 adverse event reports that name Acyclovir sodium. In these reports the drug is a suspect or interacting product.

In the same period, 923 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 28 reports in the 12 months to June 2026 and 7 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

The number of people who use the product is not in the data. A count is not a rate. A count of reports is not a count of events or of patients, because one event can have more than one report.

There are many instances of duplicative reports and some reports do not contain all the necessary information.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Acyclovir sodium is suspect or interacting. FDA says:

Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Data version

openFDA FAERS release of 1 Oct 2026. Reports received through 30 Jun 2026.

Since the last update

FDA says:

Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The information in these reports cannot be used to estimate the incidence (occurrence rates) of the events reported.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

No update is on record for this page. The record starts when FDA adds the reports of July to September 2026.

In April to June 2026, FDA received 3 reports that name Acyclovir sodium.
In January to March 2026, FDA received 10.
In April to June 2025, FDA received 1.

April to June 2026 is the latest closed quarter in the data. A closed quarter is a quarter for which the FDA files have most of the reports.

All updates Feed of updates (RSS)

Reaction lookup

These are the reaction terms that the reports record, with the number of reports for each term. Type a term or a plain word to find its count.

What this list leaves out

The table lists the 68 reaction terms that 5 or more reports record. A term with fewer than 5 reports is not in the table.

This list is partial.

It covers 327 of the 407 reports (80.3%).

The site keeps reaction terms only for years in which the drug has 12 or more reports.

So a count in the table can be lower than the count of FDA.

Find a reaction term

The table shows the first 50 of 68 terms.

Reaction terms in the reports that name Acyclovir sodium, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 407 reports
Asthma	61	15%
Therapeutic product effect incomplete	60	14.7%
Sleep disorder due to a general medical condition	59	14.5%
Dyspnoeashortness of breath	55	13.5%
Headachehead pain	52	12.8%
Hypothyroidismunderactive thyroid	51	12.5%
Loss of personal independence in daily activities	50	12.3%
Blood test abnormal	49	12%
Burning sensationa burning feeling	49	12%
Cardiac disorder	49	12%
Fibromyalgia	49	12%
Gastrooesophageal reflux diseaseacid reflux	49	12%
Hypertensionhigh blood pressure	49	12%
Sensitisation	49	12%
Acute kidney injurysudden loss of kidney function	48	11.8%
Carpal tunnel syndrome	48	11.8%
Drug ineffectivethe medicine did not work as expected	48	11.8%
Rhinitis allergic	48	11.8%
Wheezing	48	11.8%
Sleep apnoea syndromepauses in breathing during sleep	47	11.5%
Polycystic ovaries	46	11.3%
Ejection fraction	44	10.8%
Renal disorder	43	10.6%
Full blood count abnormal	41	10.1%
Intentional product use issuedeliberate use not as intended	33	8.1%
Ejection fraction abnormal	31	7.6%
Nephrectomy	31	7.6%
Obstructive sleep apnoea syndrome	31	7.6%
Adverse eventan unwanted medical event, type not specified	27	6.6%
Hospitalisationadmission to hospital	27	6.6%
Nephropathy	24	5.9%
Off label useused for a purpose or in a way not on the label	22	5.4%
Sleep disorder due to general medical condition, insomnia type	18	4.4%
Epstein-Barr virus infection	15	3.7%
Haemorrhage intracranial	15	3.7%
Multiple organ dysfunction syndromeseveral organs failing	15	3.7%
Post transplant lymphoproliferative disorder	15	3.7%
Smooth muscle cell neoplasm	15	3.7%
Blood creatinine increasedraised creatinine, a kidney test	14	3.4%
Cytomegalovirus infection	14	3.4%
Anaemialow red blood cells	12	2.9%
Gastric ulcera stomach ulcer	11	2.7%
Neurotoxicity	11	2.7%
Antineutrophil cytoplasmic antibody positive	10	2.5%
Disease recurrencethe disease came back	10	2.5%
Nasal polyps	10	2.5%
Renal failurekidney failure	10	2.5%
Astheniaweakness or lack of energy	8	2%
Rashskin rash	8	2%
Condition aggravatedthe condition being treated got worse	7	1.7%

Download all 68 terms of Acyclovir sodium (CSV)

The counts add to more than 407 reports, because one report can record more than one term. FDA says:

No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The CSV file has the same rows and the same limits. Its last row is a note that says so.

MedDRA term

The person who codes a report selects the preferred term that agrees best with the description of the reporter. The words under a term are the plain meaning that this site gives.

Not the label

The FDA-approved label of a product lists its adverse reactions. See the official pages at the end of this page.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Acyclovir with a page, in the order generic names, brand names, names as reported
Name	Name type	Reports
Acyclovir	Generic name	11,095
Acyclovir sodium (this page)	Generic name	407
Zovirax	Brand name	2,423

Sum of the separately reported names: 13,925. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

FDA says:

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.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Outcomes by year

The table gives the outcomes that the reporters gave, in the terms of FDA.

Outcomes in the reports that name Acyclovir sodium, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA file	Reports	Serious	Death	Life-threatening	Hospitalization (initial or prolonged)	Disability or Permanent Damage	Congenital Anomaly/Birth Defect	Other Serious (Important Medical Events)	Not serious
2004	5	1	0	0	1	0	0	0	4
2005	4	1	0	1	1	0	0	0	3
2006	6	6	1	0	4	0	0	2	0
2007	2	2	0	1	1	0	0	1	0
2008	11	10	0	0	4	0	0	7	1
2009	25	9	4	1	6	0	0	2	16
2010	66	56	5	11	27	5	0	28	10
2011	6	6	1	0	3	0	0	6	0
2012	17	17	3	0	7	0	0	11	0
2013	9	9	1	1	2	1	0	8	0
2014	2	2	0	0	0	0	0	2	0
2015	10	8	0	1	4	0	0	4	2
2016	8	8	1	5	5	0	0	6	0
2017	14	13	1	7	8	1	0	9	1
2018	7	7	1	1	2	0	0	6	0
2019	14	13	5	2	3	1	0	11	1
2020	25	25	12	1	3	1	0	17	0
2021	39	38	4	2	15	1	0	22	1
2022	32	31	4	0	18	0	0	29	1
2023	44	44	5	5	27	0	1	39	0
2024	12	11	2	0	7	0	0	11	1
2025	32	31	2	7	24	0	0	20	1
2026	17	17	1	2	8	0	0	14	0

An outcome in a report is not proof that the drug was the cause. The reporter gives the outcome, and FDA does not verify it. FDA says:

The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The six headings with the names of FDA are the outcome terms of FDA. A report can have more than one outcome. The columns Serious and Not serious are the two values of the openFDA field serious. For the value serious, openFDA gives this description:

The adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition
Source: openFDA, Drug adverse event fields (YAML reference). The site read the page on 2 Oct 2026.

The year is the year of the openFDA file that holds the latest version of the report. It is not always the year in which FDA first received the report. The chart of the next section uses the year of first receipt. The latest year is not complete.

Reports by year and month

Reports that name Acyclovir sodium, by the year in which FDA received them

The column of 2026 has an outline, because the year is not complete. It has the reports that FDA received through June 2026 only.

Show the figures of the chart as a table

Reports that name Acyclovir sodium, by the year in which FDA received them
Year	Reports
2004	4
2005	1
2006	10
2007	2
2008	11
2009	9
2010	81
2011	7
2012	17
2013	9
2014	2
2015	10
2016	11
2017	11
2018	9
2019	14
2020	45
2021	44
2022	35
2023	35
2024	8
2025	19
2026	13

Reports that name Acyclovir sodium, by month, five years to June 2026

FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Why a count moves

A count moves for many reasons. The guide gives FDA's words about them.

Patients and reporters

Age of the patient in the reports that name Acyclovir sodium
Age	Reports	Share
Under 2	21	5.2%
2 to 11	15	3.7%
12 to 17	12	2.9%
18 to 44	71	17.4%
45 to 64	114	28%
65 to 74	32	7.9%
75 and over	50	12.3%
Age not given	92	22.6%

Sex of the patient in the reports that name Acyclovir sodium
Sex	Reports	Share
Female	215	52.8%
Male	149	36.6%
Unknown or not given	43	10.6%

Type of reporter in the reports that name Acyclovir sodium
Reporter	Reports	Share
Physician	88	21.6%
Pharmacist	53	13%
Other health professional	187	45.9%
Lawyer	0	0%
Consumer or non-health professional	65	16%
Not given	14	3.4%

Age and sex are as the report gives them. The reporter is the primary source in the report. 25.1% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Acyclovir sodium record
Indication as recorded (MedDRA)	Reports	Share
Herpes zoster	31	7.6%
Antiviral prophylaxis	26	6.4%
Steroid dependence	10	2.5%
Encephalitis herpes	7	1.7%
Off label use	7	1.7%
Genital herpes	5	1.2%

The reporter fills in the indication, and the field is often empty. Each share is of all 407 reports.

Pages near this one

Acyclovir same ingredient
Zovirax same ingredient
Famciclovir same class
Valacyclovir same class
Valacyclovir hydrochloride same class
Acz885 next in the A to Z list
Acupan next in the A to Z list
Aczone next in the A to Z list
Acular next in the A to Z list
Adakveo next in the A to Z list
Actrapid next in the A to Z list
Adalat next in the A to Z list

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

DailyMed labels for Acyclovir sodiumThe labels (prescribing information) that have this name, at the National Library of Medicine.
MedWatch Online Voluntary Reporting FormThe online form of FDA for a voluntary report.
MedWatch: The FDA Safety Information and Adverse Event Reporting ProgramThe page of the FDA program that receives reports about drugs and devices.
FDA Adverse Event Monitoring System (AEMS) Public DashboardThe public dashboard of FDA for adverse event reports on drugs and biologics.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Reported Reactions. Acyclovir sodium: adverse event reports that FDA received. https://reportedreactions.com/drug/acyclovir-sodium/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of 1 Oct 2026. Reports received through 30 Jun 2026.

Where the data come from

The counts come from the openFDA Drug Adverse Event (FAERS) bulk files, release of 1 Oct 2026. The files have the reports that FDA received through 30 Jun 2026. A drug name is the name on the report. The site matches it to a brand name or a generic name of the National Drug Code Directory of 2 Oct 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Acyclovir sodium as a suspect or interacting product. The 923 reports that name it only as a concomitant medicine are not in the count. The site does not publish a report narrative, a lot number, a detail of a patient or the identity of a reporter. The record of FDA is the authority. See how the site counts reports, the data sources and the corrections page.

Questions

Do these reports show that Acyclovir sodium was responsible for the reactions?

No. FDA says:

For any given report, there is no certainty that a suspected drug caused the event.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

A reaction can relate to the condition that the drug treats, to other medicines, or to something else.

Is this the list of reactions on the label of Acyclovir sodium?

No. It is a count of what people reported to FDA: 407 reports from January 2004 to May 2026. The FDA-approved label of a product lists its adverse reactions. The official pages at the end of this page link to the labels.

Who sent these reports?

Other health professional (45.9%), physician (21.6%) and consumer or non-health professional (16%). These are the types of reporter for the reports that name this drug.

If a manufacturer receives an adverse event report, it is normally required to send the report to FDA.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

How does a person report an adverse event?

FDA runs MedWatch, a program that takes voluntary reports from health professionals, patients and consumers. The guide on how to report has the links.

To the top of the page