VALTREX FDA MedWatch Direct Reports Summary

These tables and charts are created from 796 voluntary U.S. reports for VALTREX (VALACYCLOVIR HYDROCHLORIDE) reported by individuals to the FDA via the MedWatch Reporting System from 2004 through April 28, 2026.

For a summary of adverse events including mandatory reports submitted by pharmaceutical companies (all countries and all reporter types) to the FAERS database, View FDA FAERS VALTREX Report.

Top Adverse Effects Associated with VALTREX (from U.S. FDA Medwatch Reports)

	Side Effect	# of FDA Reports
1	NAUSEA	57
2	HEADACHE	48
3	FATIGUE	45
4	DIARRHEA	40
5	DIZZINESS	38
6	DRUG INEFFECTIVE	34
7	PRODUCT SUBSTITUTION ISSUE	33
8	FEELING ABNORMAL	31
9	ANXIETY	30
10	LACK OF STRENGTH AND ENERGY (ASTHENIA)	29
11	INSOMNIA	29
12	RASH	29
13	DEPRESSION	28
14	PAIN	28
15	SHORTNESS OF BREATH	27
16	ITCHING	26
17	FEVER	26
18	VOMITING	25
19	THERAPY CESSATION	23
20	JOINT PAIN	22
21	HOSPITALIZATION	22
22	PAIN IN EXTREMITY	22
23	DEATH	21
24	DISEASE PROGRESSION	19
25	TREMOR	17

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VALTREX Total Medwatch Safety Reports by Patient Sex

Male	Female	Unknown	Total
198	586	12	796

Medwatch Reporter Type	Count
Consumer	345
Physician	44
Pharmacist	109
Other Health Professional	121

Top Indications

SHINGLES
Product used for unknown indication
Herpes simplex
Keratitis
Infection

Type of Outcome Reported
Serious: 598
Not Serious: 198
Note: A serious outcome means the adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition.

Suspected Role
Primary Suspect: 796
Concomitant Drugs: 757
Note: A single MedWatch report can list more than one drug. This summary includes VALTREX identified as the suspect drug or as a concomitantly taken drug.

FDA Safety-Related Labeling Changes

VALTREX (VALACYCLOVIR HYDROCHLORIDE) Rx Drug:
FDA Safety-related Labeling Changes

Risk of severe cutaneous adverse reactions (SCARs)

Have experience (good or bad) with VALTREX? Rate VALTREX at Ask a Patient.

For serious adverse events, report them to the FDA by contacting the drug manufacturer or report directly through the MedWatch voluntary reporting form.

NOTES

This report, created by AskaPatient.com, is derived from U.S. drug-related adverse event cases that were reported directly to the FDA using the voluntary MedWatch online or paper reporting system. MedWatch is the voluntary FDA system for consumers, physicians, and others to directly report adverse reactions. The Medwatch initiative was launched in 1993 as a voluntary reporting program for consumers, physicians and other healthcare practitioners.

After processing the received forms, the FDA adds the MedWatch reports to the FDA Adverse Events Reporting System(or FAERS database.) Click here for the complete FAERS report summary, which includes mandatory reports submitted by pharmaceutical companies (worldwide) combined with the MedWatch reports. MedWatch Reports only represent about 5% of the FAERS database. For more, read "Does the FDA's Rapidly Growing Database of Adverse Events Improve Drug Safety?"

The data in this report was obtained from Open FDA. Data was last updated to include reports through January 27, 2026. The reactions, side effects, or "adverse events," represent up to the 20 most frequently occuring events in the database for a drug related to the event.

Open FDA states that it only includes the most recent version of a case report. It also adds the disclaimer: "Do not rely on Open FDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated."

FDA uses the "MedDRA" classification system to describe reported adverse reactions. MedDRA is a standardized medical terminology that facilitates sharing of regulatory information internationally. In some cases, "patient friendly" terms for the layman designated by MedDRA have been substituted for medical jargon. Please contact us with questions about this report.