Histone Deacetylase Inhibitor side effects compared: 4 drugs, 4,715 FDA adverse event reports
Members
| Drug | FAERS reports | Serious | Death outcome | Boxed warning | Top labeled signals | Unlabeled (unassessed) |
|---|---|---|---|---|---|---|
| Vorinostat (Zolinza) | 2,146 | 87% | 420 | – | Febrile neutropenia; Thrombocytopenia; Anaemia | Electrocardiogram qt prolonged; Acute myeloid leukaemia |
| Romidepsin | 1,664 | 87% | 444 | – | Thrombocytopenia; Platelet count decreased; Electrocardiogram qt prolonged | – |
| Givinostat (Duvyzat) | 558 | 26% | 15 | – | Platelet count decreased; Blood triglycerides increased | – |
| Belinostat (Beleodaq) | 347 | 89% | 116 | – | Neutrophil count decreased | – |
Class-wide signals (flagged in at least 2 of 4 members)
| Reaction | Members flagged | Median PRR | Reports (sum) | In label |
|---|---|---|---|---|
| Hypocalcaemia | 2/4 | 27.3 | 38 | 0/2 members' labels |
| Sinus tachycardia | 2/4 | 26.9 | 21 | 0/2 members' labels |
| Febrile neutropenia | 2/4 | 22.2 | 286 | 2/2 members' labels |
| Electrocardiogram qt prolonged | 2/4 | 21.5 | 138 | 1/2 members' labels |
| Lymphopenia | 2/4 | 21.3 | 57 | 1/2 members' labels |
| Haematotoxicity | 2/4 | 19.2 | 32 | 0/2 members' labels |
| Acute myeloid leukaemia | 2/4 | 17.4 | 52 | 0/2 members' labels |
| Thrombocytopenia | 2/4 | 13.4 | 271 | 2/2 members' labels |
| Bone marrow failure | 2/4 | 8.2 | 31 | 1/2 members' labels |
| Neutropenia | 2/4 | 6.2 | 154 | 2/2 members' labels |
Member-specific signals (flagged in exactly one drug)
| Reaction | Drug | Reports | PRR | Label screen |
|---|---|---|---|---|
| Hypokalaemia | Vorinostat | 52 | 11.1 | Labeled adverse reaction |
| Sepsis | Vorinostat | 111 | 9.7 | Labeled adverse reaction |
| Atrial fibrillation | Romidepsin | 61 | 7.9 | Labeled (related wording) |
| Dehydration | Vorinostat | 102 | 7.5 | Labeled adverse reaction |
| Respiratory failure | Vorinostat | 52 | 7.0 | Labeled (related wording) |
| Anaemia | Vorinostat | 135 | 6.9 | Labeled adverse reaction |
Common questions
Which histone deacetylase inhibitor has the most FDA adverse event reports?
Vorinostat has the most FAERS co-reports in this class (2,146), followed by Romidepsin (1,664). Report volume tracks how widely and how long a drug has been used, and how much attention it has had, far more than its risk.
Which side effects are shared across histone deacetylase inhibitor drugs?
Reaction terms flagged in at least half of the 4 members include hypocalcaemia, sinus tachycardia, febrile neutropenia, electrocardiogram qt prolonged, lymphopenia. A term shared across a class usually reflects the shared mechanism (or the shared patient population) rather than one product.
Does a FAERS signal mean the drug causes the reaction?
No. These are disproportionality signals from voluntary reports with no denominator. Each is screened against the FDA label (known vs unlabeled) on the drug pages; causality needs temporality, dose-response, plausibility and trial or cohort evidence.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, seriousness and death counts from openFDA count queries. Generated 2026-10-08. Not medical advice.