What the label lists and what reports show
Valganciclovir side effects
Valganciclovir's FDA label: “The most common adverse reactions and laboratory abnormalities reported in at least one indication by greater than or equal to 20% of adult patients treated with VALCYTE tablets are diarrhea, pyrexia, fatigue, nausea, tremor, neutropenia, anemia, leukopenia …” FAERS holds 18,742 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is cytomegalovirus infection (1,821 reports).
- Generic listed
- Boxed warning
Check it at the source: the valganciclovir FDA label on DailyMed (effective December 8, 2025, H2-Pharma, LLC); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of VALCYTE?VALCYTE may cause serious side effects, including: See " What is the most important information I should know about VALCYTE? " The most common side effects of VALCYTE in adults include: diarrhea fever fatigue nausea shaky movements (tremors) low white cell, red cell and platelet cell counts in blood tests headache sleeplessness urinary tract infection vomiting The most common side effects of VALCYTE in children include: diarrhea fever upper respiratory tract infection urinary tract infection vomiting low white blood cell counts in blood tests headache These are not all the possible side effects of VALCYTE. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, NDA021304 (Cheplapharm), as published by H2-Pharma, LLC, effective December 8, 2025 (SPL set 4c517a39-2ded-4c5a-8d56-276853414b31), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions and laboratory abnormalities reported in at least one indication by greater than or equal to 20% of adult patients treated with VALCYTE tablets are diarrhea, pyrexia, fatigue, nausea, tremor, neutropenia, anemia, leukopenia, thrombocytopenia, headache, insomnia, urinary tract infection, and vomiting.
Table 3 Pooled Selected Adverse Reactions Reported in greater than or equal to 5% of Patients who Received VALCYTE Tablets Maintenance Therapy for CMV Retinitis
| Reaction | Patients with CMV Retinitis VALCYTE Tablets (N=370) % Gastrointestinal system |
|---|---|
| Diarrhea | 41 |
| Nausea | 30 |
| Vomiting | 21 |
| Abdominal pain | 15 |
| Pyrexia | 31 |
| Headache | 22 |
| Insomnia | 16 |
| Neuropathy peripheral | 9 |
| Paresthesia | 8 |
| Retinal detachment | 15 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are discussed in greater detail in other sections of the labeling: Hematologic Toxicity [see Warnings and Precautions (5.1) ]. Acute Renal Failure [see Warnings and Precautions (5.2) ]. Impairment of Fertility [see Warnings and Precautions (5.3) ]. Fetal Toxicity [see Warnings and Precautions (5.4) ]. Mutagenesis and Carcinogenesis [see Warnings and Precautions (5.5) ]. The most common adverse reactions and laboratory abnormalities reported in at least one indication by greater than or equal to 20% of adult patients treated with VALCYTE tablets are diarrhea, pyrexia, fatigue, nausea, tremor, neutropenia, anemia, leukopenia, thrombocytopenia, headache, insomnia, urinary tract infection, and vomiting. The most common reported adverse reactions and laboratory abnormalities reported in greater than or equal to 20% of pediatric solid organ transplant recipients treated with VALCYTE for oral solution or tablets are diarrhea, pyrexia, upper respiratory tract infection, urinary tract infection, vomiting, neutropenia, leukopenia, and headache. …
Source: FDA drug label, NDA021304 (Cheplapharm), as published by H2-Pharma, LLC, effective December 8, 2025 (SPL set 4c517a39-2ded-4c5a-8d56-276853414b31), via openFDA; the full label on DailyMed
What do FAERS reports show?
18,742 reports list valganciclovir among the medicines taken, each a report of something that happened, not proof the medicine caused it; 3,234 are coded as a death and 9,212 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. Of the 20 reactions below, 13 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Valganciclovir: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions