Drug profile

The FDA adverse-event record for Narasin; Nicarbazin

18 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Narasin; Nicarbazin. See the species affected, top reactions, and outcomes below.

18
adverse-event reports
11.1%
death-coded share
Chicken
most-reported species
17
Lack of efficacy (protozoa) - Coccidia - 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.
18
Total Reports
2
Deaths Reported
11.1%
Death Rate

Active Ingredients

Narasin; Nicarbazin

Administration Routes

Oral

Species Affected

Chicken 18

Most Affected Breeds

Chicken (other) 12
Cornish Cobb 3
Chicken (unknown) 3

Most Reported Reactions

Lack of efficacy (protozoa) - Coccidia 17
Overdose 3
Increased mortality rate 2
Digestive tract disorder NOS 1
Enteritis 1
Death 1
Lack of efficacy - NOS 1
Loss of condition 1
Poor feed conversion 1
Incoordination 1

Outcome Breakdown

Outcome Unknown
18 (90.0%)
Died
2 (10.0%)

Narasin; Nicarbazin Adverse Event Insights

18 reports name Narasin; Nicarbazin; 2 recorded a death outcome (11.1% of reported events, not a population-level mortality rate). Active ingredient: Narasin; Nicarbazin. Administration route: Oral.

By species: Chicken (18 reports). By breed: Chicken (other) (12), Cornish Cobb (3), Chicken (unknown) (3).

Leading clinical signs: Lack of efficacy (protozoa) - Coccidia (17), Overdose (3), Increased mortality rate (2), Digestive tract disorder NOS (1). Outcome, 20 coded reports: Outcome Unknown leads at 90.0%.

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.