Cytochrome P450 3A Inhibitor side effects compared: 3 drugs, 31,416 FDA adverse event reports
Members
| Drug | FAERS reports | Serious | Death outcome | Boxed warning | Top labeled signals | Unlabeled (unassessed) |
|---|---|---|---|---|---|---|
| Ritonavir | 29,045 | 91% | 2,637 | boxed | Virologic failure; Lipodystrophy acquired; Immune reconstitution syndrome | Bone demineralisation; Mitochondrial toxicity |
| Darunavir Ethanolate and Cobicistat (Prezcobix, Prezcobix Ped) | 1,753 | 66% | 135 | – | Pain; Renal failure; Acute kidney injury | Emotional distress; Anxiety |
| Cobicistat (Tybost) | 618 | 94% | 64 | – | Rhabdomyolysis | Serotonin syndrome; Adrenal insufficiency |
Class-wide signals (flagged in at least 2 of 3 members)
| Reaction | Members flagged | Median PRR | Reports (sum) | In label |
|---|---|---|---|---|
| Anhedonia | 2/3 | 99.1 | 397 | 0/2 members' labels |
| Osteopenia | 2/3 | 54.9 | 121 | 0/2 members' labels |
| Brain injury | 2/3 | 44.3 | 43 | 0/2 members' labels |
Member-specific signals (flagged in exactly one drug)
No strong single-member signals (n ≥ 50) in this class.
Common questions
Which cytochrome p450 3a inhibitor has the most FDA adverse event reports?
Ritonavir has the most FAERS co-reports in this class (29,045), followed by Darunavir Ethanolate and Cobicistat (1,753). 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 cytochrome p450 3a inhibitor drugs?
Reaction terms flagged in at least half of the 3 members include anhedonia, osteopenia, brain injury. 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.