Drug class · FAERS comparison

HER2/neu Receptor Antagonist side effects compared: 5 drugs, 42,853 FDA adverse event reports

Class as assigned in the FDA label (Established Pharmacologic Class) · data 2026-09-14

How to read this page. Report counts are not incidence rates: a drug with more reports is usually older, more widely used or more publicised, not more dangerous. Signals are screened against each product's FDA label on its own page; a term flagged across most of a class usually reflects the shared mechanism or the shared patient population.

Members

Drug	FAERS reports	Serious	Death outcome	Boxed warning	Top labeled signals	Unlabeled (unassessed)
Pertuzumab (Perjeta)	27,021	85%	2,685	boxed	Ejection fraction decreased; Radiation skin injury; Nail bed inflammation	Myelosuppression; Metastases to central nervous system
Pertuzumab (Perjeta)	13,426	94%	1,374	boxed	Diarrhoea; Injection site pain; Neuropathy peripheral	Injection site reaction; Metastases to central nervous system
Trastuzumab-Anns (Kanjinti)	1,503	24%	24	boxed	Circumstance or information capable of leading to medication error; Chills; Infusion related reaction	Intercepted product preparation error
Ontruzant	522	93%	28	boxed	Hypokalaemia; Ejection fraction decreased; Cardiovascular disorder	–
Trastuzumab-Qyyp (Trazimera)	381	75%	40	boxed	Infusion related reaction	–

Class-wide signals (flagged in at least 3 of 5 members)

Reaction	Members flagged	Median PRR	Reports (sum)	In label
Infusion related reaction	3/5	7.6	104	3/3 members' labels

Member-specific signals (flagged in exactly one drug)

Reaction	Drug	Reports	PRR	Label screen
Her2 positive breast cancer	Pertuzumab	117	362.2	Likely indication confounding
Lacrimal structure injury	Pertuzumab	59	143.7	Not in label — unassessed
Delusion of grandeur	Pertuzumab	63	127.1	Not in label — unassessed
Circumstance or information capable of leading to medication error	Trastuzumab-Anns	257	107.7	Labeled (related wording)
Dacryostenosis acquired	Pertuzumab	77	48.9	Not in label — unassessed
Metastases to skin	Pertuzumab	58	46.5	Not in label — unassessed
Streptococcal sepsis	Pertuzumab	57	38.9	Not in label — unassessed
Radiation skin injury	Pertuzumab	55	38.5	Labeled adverse reaction
Breast cancer recurrent	Pertuzumab	138	35.5	Not in label — unassessed
Mastectomy	Pertuzumab	75	34.8	Not in label — unassessed
Injection site reaction	Pertuzumab	161	10.7	Not in label — unassessed
Chills	Trastuzumab-Anns	58	6.9	Labeled adverse reaction
Neuropathy peripheral	Pertuzumab	67	3.2	Labeled adverse reaction
Injection site pain	Pertuzumab	210	3.2	Labeled (related wording)
Diarrhoea	Pertuzumab	403	2.9	Labeled adverse reaction

Common questions

Which her2/neu receptor antagonist has the most FDA adverse event reports?

Pertuzumab has the most FAERS co-reports in this class (27,021), followed by Pertuzumab (13,426). 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 her2/neu receptor antagonist drugs?

Reaction terms flagged in at least half of the 5 members include infusion related reaction. 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.