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GentaMax 100

This page contains information on GentaMax 100 for veterinary use.
The information provided typically includes the following:
  • GentaMax 100 Indications
  • Warnings and cautions for GentaMax 100
  • Direction and dosage information for GentaMax 100

GentaMax 100

This treatment applies to the following species:
Company: Clipper (Phoenix Pharm.)

(Gentamicin Sulfate Solution)

ANADA 200-395, Approved by FDA

100 mg/mL

For Use in Horses Only

GentaMax 100 Caution

Federal law restricts this drug to use by or on the order of a licensed veterinarian.


Each mL of Gentamicin sulfate veterinary equivalent to 100 mg gentamicin base; 2.4 mg sodium metabisulfite; 0.8 mg sodium sulfite, anhydrous; 0.1 mg edetate disodium; 10 mg benzyl alcohol as preservative; water for injection q.s.

CHEMISTRY: Gentamicin is a mixture of aminoglycoside antibiotics derived from the fermentation of Micromonospora purpurea. Gentamicin sulfate is a mixture of sulfate salts of the antibiotics produced in this fermentation. The salts are weakly acidic, freely soluble in water, and stable in solution.

ANTIBACTERIAL ACTIVITY: In vitro antibacterial activity has shown that gentamicin is active against most gram-negative and gram-positive bacteria isolated from domestic animals.1 Gentamicin is active against Pseudomonas aeruginosa, indole-positive and -negative Proteus species, Escherichia coli, Klebsiella species, Enterobacter species, Alcaligenes species, Staphylococcus species, and Streptococcus species.


Studies in man indicate that recommended doses of gentamicin produce serum concentrations bactericidal for most bacteria sensitive to gentamicin within an hour after intramuscular injection; these concentrations last for 6 to 12 hours.2 Some 30% of the administered dose of gentamicin is bound by serum proteins and released as the drug is excreted.

Gentamicin is excreted almost entirely by glomerular filtration. High concentrations of the active form are found in the urine. Fifty to 100% of the gentamicin injected can be recovered unchanged within 24 hours from the urine of patients with normal renal function. A small amount is excreted into the bile.

TOXICITY STUDIES: No toxic effects were observed in rats given gentamicin sulfate 20 mg/kg/day for 24 days; in cats given 10 mg/kg/day for 40 days. Gentamicin sulfate given to dogs at 6 mg/lb/day, 6 days weekly for 3 weeks, caused no detectable kidney damage. At higher doses, impairment of equilibrium and renal function were observed in these species.

GentaMax 100 Indications

GentaMax® 100 (Gentamicin Sulfate Solution) is recommended for the control of bacterial infections of the uterus (metritis) in horses and as an aid in improving conception in mares with uterine infections caused by bacteria sensitive to gentamicin.

Bacteriologic studies should be conducted to identify the causative organism and to determine its sensitivity to gentamicin sulfate. Sensitivity discs of the drug are available for this purpose.

Dosage and Administration

The recommended dose is 20 to 25 mL (2.0 - 2.5 grams) gentamicin sulfate solution per day for 3 to 5 days during estrus. Each dose should be diluted with 200-500 mL of sterile physiological saline before aseptic uterine infusion.


There are no known contraindications to this drug when used as directed.

PRECAUTION: If hypersensitivity to any of the components develops, or if overgrowth of nonsusceptible bacteria, fungi, or yeasts occurs, treatment with GentaMax® 100 (Gentamicin Sulfate Solution) should be discontinued and appropriate therapy instituted.

Although GentaMax® 100 (Gentamicin Sulfate Solution) is not spermicidal, treatment should not be given the day of breeding.


Do not use for horses intended for human consumption.

Side Effects

There have been no reports of drug hypersensitivity or adverse side effects following the recommended intrauterine infusion of gentamicin sulfate solution combined with sterile physiological saline in mares.

How Supplied

GentaMax® 100 (Gentamicin Sulfate Solution), 100 mg per mL for intrauterine use, is available in 100 mL and 250 mL multiple dose vials.

For intra-uterine use in horses only.

Store between 2° and 30°C (36° and 86°F). Protect from freezing.


1. Hennessey, PW, et al. In vitro activity of gentamicin against bacteria isolated from domestic animals. Veterinary Medicine/Small Animal Clinician. Nov. 1971; 1118-1122.

2. Black, J, et al. Pharmacology of gentamicin, a new broad spectrum antibiotic. Antimicrob Agents and Chemother. 1963; 138-147.


Manufactured for: Clipper Distributing Company, LLC, St. Joseph, MO 64507

Trademarks are property of Clipper Distributing Company, LLC

Manufactured by Sparhawk Laboratories, Inc., Lenexa, KS 66215, USA

Mfd. in U.S.A.

Net Contents:



100 mL Sterile Multiple Dose Vial


G-6336-04 Rev. 09-10

250 mL Sterile Multiple Dose Vial


G-6336-05 Rev. 07-10

CPN: 1256155.3


1302 SOUTH 59 STREET, ST. JOSEPH, MO, 64507
Telephone:   816-364-5777
Order Desk:   800-759-3644
Every effort has been made to ensure the accuracy of the GentaMax 100 information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the US product label or package insert.

Copyright © 2020 Animalytix LLC. Updated: 2020-10-21