Drug profile

The FDA adverse-event record for Fipronil, Etofenprox, (S)-Methoprene

41 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Fipronil, Etofenprox, (S)-Methoprene. See the species affected, top reactions, and outcomes below.

41
adverse-event reports
0.0%
death-coded share
Cat
most-reported species
25
Lack of efficacy (ectoparasite) - flea - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
41
Total Reports
0
Deaths Reported
0.0%
Death Rate

Active Ingredients

Fipronil, Etofenprox, (S)-Methoprene

Administration Routes

TopicalUnknown

Species Affected

Cat 41

Most Affected Breeds

Domestic Shorthair 22
Domestic Longhair 7
Cat (unknown) 6
Maine Coon 3
Russian 1
Mixed (Cat) 1
Domestic (unspecified) 1

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 25
Behavioural disorder NOS 6
Itching 5
Hyperactivity 5
Lack of efficacy - NOS 4
Application site hair loss 4
Application site reddening 4
Licking 3
Excessive chewing, licking and/or grooming 3
Application site bleeding 2
Application site reaction NOS 2
Scratching 2

Outcome Breakdown

Outcome Unknown
36 (87.8%)
Recovered/Normal
5 (12.2%)

Fipronil, Etofenprox, (S)-Methoprene Adverse Event Insights

41 reports name Fipronil, Etofenprox, (S)-Methoprene; 0 recorded a death outcome (0.0% of reported events, not a population-level mortality rate). Active ingredient: Fipronil, Etofenprox, (S)-Methoprene. Administration routes: Topical, Unknown.

By species: Cat (41 reports). By breed: Domestic Shorthair (22), Domestic Longhair (7), Cat (unknown) (6).

Leading clinical signs: Lack of efficacy (ectoparasite) - flea (25), Behavioural disorder NOS (6), Itching (5), Hyperactivity (5). Outcome, 41 coded reports: Outcome Unknown leads at 87.8%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.