HIGH-VOLUME · HOSP-HEAVY
acyclovir Side Effects
acyclovir (also sold as Zovirax) is HIGH-VOLUME in this FAERS book #70 of 524 by FAERS report count. Signature opener: HOSP-HEAVY - 37.1% mention hospitalization (40,651 reports).
Data updated 2026-05-15
- 109,698
- FAERS reports
FAERS voluntary reports, 2003 to 2025. High volume tracks exposure and reporting culture; see methodology for de-dup rules.
acyclovir: 37.1% mention hospitalization (40,651 reports). Death stamp DEATH-HEAVY; volume band HIGH-VOLUME #70 of 524 by FAERS report count.
High-report extract for acyclovir (Zovirax): 109,698 FAERS rows (2003-2025). Top named reactions: FATIGUE, DIARRHOEA, PNEUMONIA. Outcome stamps DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED. FAERS is voluntary signal detection, not incidence.
Counts from the openFDA FAERS extract (2003–2025). Stamps MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED.
FATIGUE leads 7,612 of 109,698 reports
Who reports · age peak 45-64 (SEX-BALANCED)
Sex coding · SEX-BALANCED
Age peak 45-64 (23,378 reports)
FAERS filings rising toward 2025
Reactions in Death Reports
Death-mentioned subset is HEAVY here (13,944 reports, 12.7%). Top co-reported reactions in that subset - voluntary, not causal.
| Reaction | Reports |
|---|---|
| DEATH | 4,656 |
| PNEUMONIA | 1,070 |
| SEPSIS | 977 |
| PLASMA CELL MYELOMA | 784 |
| PYREXIA | 728 |
| RESPIRATORY FAILURE | 677 |
| SEPTIC SHOCK | 657 |
| MULTIPLE ORGAN DYSFUNCTION SYNDROME | 536 |
| DISEASE PROGRESSION | 528 |
| FEBRILE NEUTROPENIA | 512 |
| THROMBOCYTOPENIA | 504 |
| DIARRHOEA | 465 |
| RENAL FAILURE | 447 |
| NEUTROPENIA | 431 |
| ANAEMIA | 423 |
| INFECTION | 420 |
| PLATELET COUNT DECREASED | 415 |
| ACUTE KIDNEY INJURY | 396 |
Reactions in Hospitalization Reports
Hospitalization is HEAVY (40,651, 37.1% of the book). Top reactions in those rows:
| Reaction | Reports |
|---|---|
| PNEUMONIA | 4,416 |
| PYREXIA | 3,261 |
| DIARRHOEA | 2,437 |
| FEBRILE NEUTROPENIA | 2,197 |
| NAUSEA | 2,046 |
| FATIGUE | 2,021 |
| DYSPNOEA | 1,846 |
| ACUTE KIDNEY INJURY | 1,618 |
| ASTHENIA | 1,564 |
| SEPSIS | 1,563 |
| VOMITING | 1,557 |
| FALL | 1,387 |
| ANAEMIA | 1,373 |
| NEUTROPENIA | 1,329 |
| PLATELET COUNT DECREASED | 1,316 |
| THROMBOCYTOPENIA | 1,235 |
| HEADACHE | 1,197 |
| HYPOTENSION | 1,160 |
How to read acyclovir FAERS figures (MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY)
FAERS holds 109,698 voluntary reports linked to acyclovir (Zovirax), 2003-2025. Death is listed on 13,944 (12.7%). Hospitalization appears on 40,651 (37.1%). Top co-reported indication: Product Used For Unknown Indication.
MEGA-CASE books overweight common drugs and loud reporting cultures; HOSP-HEAVY is the page opener, not a per-patient risk.
Read with acyclovir
Peers ranked by ABS(total_reports), then an ABS(death_share) pole; guide hop follows DEATH-HEAVY · HOSP-HEAVY stamps.
ABS(total_reports) peer at 110,018 FAERS cases (Δ 320 heavier vs acyclovir); DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED vs this page's MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED.
ABS(total_reports) peer at 109,144 FAERS cases (Δ 554 lighter vs acyclovir); DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED vs this page's MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED.
ABS(total_reports) peer at 111,257 FAERS cases (Δ 1,559 heavier vs acyclovir); DEATH-MARKED · HOSP-MID · FEMALE-LED vs this page's MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED.
ABS(total_reports) peer at 112,198 FAERS cases (Δ 2,500 heavier vs acyclovir); DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED vs this page's MEGA-CASE · DEATH-HEAVY · HOSP-HEAVY · SEX-BALANCED.
ABS(death_share) pole at 62.1% death-mentioned reports (Δ 49.4 pp vs acyclovir's DEATH-HEAVY): CASELOAD · HOSP-MID.
acyclovir stamps DEATH-HEAVY · HOSP-HEAVY; FAERS outcome shares are signal-detection rates, not incidence. Read them next to caseload MEGA-CASE and the label guide.