Stafac® and MaxibanTM — veterinary medication

Overview

Source: Animal Drugs @ FDA

Proprietary name

Stafac® and MaxibanTM

Active ingredient

Narasin Nicarbazin Virginiamycin

Application type

NADA

Sponsor

Phibro Animal Health Corp.

Applications on record

1

First published

October 3, 2022

Adverse event reports

Source: openFDA VeDDRA

556

Reports mentioning this ingredient

April 12, 1989 – February 5, 2026

271

Classified serious

per reporter assessment

156

Lack of expected efficacy

resistance signal

26

Human operator exposure

needle-stick or splash

Not a risk measure. Veterinary adverse event reports are influenced by how many animals are treated, reporting practice and product age. Reports do not establish that the product caused the event, and a single report can cover an entire herd or flock. Attribution here is by active ingredient because the source dataset redacts brand names.

Attributed by active ingredient “NARASIN”. Green Book ingredient names and VeDDRA ingredient names do not always agree exactly, so attribution is approximate and labelled as such.

Reported reactions

Source: openFDA VeDDRA

Clinical signs coded in the VICH VeDDRA four-level hierarchy, most frequent first.

Reaction terms reported for this ingredient, by report count.
Reaction (VeDDRA term)	Reports	Relative frequency
Death	220
Lack of efficacy (protozoa) - Coccidia	115
Increased mortality rate	62
Lameness	45
Granules/Powder, Abnormal	41
Death by euthanasia	39
Lack of efficacy - NOS	31
NT - Abnormal necropsy finding NOS	31
Recumbency	30
Accidental exposure	25
Enteritis	23
Digestive tract disorder NOS	21
Anorexia	19
Loss of egg quantity	18
Vocalisation	18
Systemic disorder NOS	14
Respiratory tract disorder NOS	14
Rectal prolapse	13
Loss of egg quality	12
Abnormal necropsy finding	12

Species affected

Source: openFDA VeDDRA

Chicken 311 Pig 149 Turkey 13 Human 9 Cattle 7 Dog 4 Horse 3 Sheep 1 Other Reptiles 1

Regulatory context

New Animal Drug Application (NADA). A pioneer approval evaluated for target animal safety, therapeutic effectiveness, manufacturing controls and — for food-producing species — human food safety including residue depletion.

Extra-label use in food-producing animals is governed by the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA) and 21 CFR Part 530. It requires a valid veterinarian-client-patient relationship and is prohibited outright for certain drug classes. Withdrawal times are determined by FARAD, not by this index.

Sources for this page

Animal Drugs @ FDA	FDA CVM	Applications, sponsor, status, withdrawal
Animal & Veterinary Events	FDA CVM	VeDDRA adverse event aggregates by active ingredient