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


This treatment applies to the following species:
Company: Med-Pharmex


Liquid for Horses

10 mg per mL


ANADA 200-292, Approved by FDA

Iversol Caution

Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian.


IVERSOL (ivermectin) Liquid for Horses has been formulated for professional administration by stomach tube or oral drench. One low-volume dose is effective against important internal parasites, including the arterial stages of Strongylus vulgaris, and bots.

Product Description

Ivermectin is derived from the avermectins, a family of potent, broad-spectrum antiparasitic agents, which are isolated from fermentation of Streptomyces avermitilis.

IVERSOL (ivermectin) Liquid is a clear, ready-to-use solution with each mL containing 1% ivermectin (10 mg), 0.2 mL propylene glycol, 80 mg polysorbate 80, 9 mg sodium phosphate monobasic monohydrate, 1.3 mg sodium phosphate dibasic anhydrous, 1 mg butylated hydroxytoluene, 0.1 mg disodium edetate, 3% benzyl alcohol and purified water q.s. ad 100%.

Product Indications

IVERSOL (ivermectin) Liquid is indicated for the effective treatment and control of the following parasites or parasitic conditions in horses:

Large Strongyles: Strongylus vulgaris (adults and arterial larval stages), S. edentatus (adults and tissue stages), S. equinus (adults), Triodontophorus spp (adults).

Small Strongyles - (adults, including those resistant to some benzimidazole class compounds): Cyathostomum spp, Cylicocyclus spp, Cylicostephanus spp, Cylicodontophorus spp., Small Strongyles - fourth-stage larvae

Pinworms (adults and fourth-stage larvae): Oxyuris equi

Ascarids (adults and third- and fourth-stage larvae): Parascaris equorum

Hairworms (adults): Trichostrongylus axei

Large-mouth Stomach Worms (adults): Habronema muscae

Bots (oral and gastric stages): Gastrophilus spp

Lungworms (adults and fourth-stage larvae): Dictyocaulus arnfieldi

Intestinal Threadworms (adults): Strongyloides westeri

Summer Sores caused by Habronema and Draschia spp cutaneous third-stage larvae.

Dermatitis caused by neck threadworm microfilariae, Onchocerca sp.


IVERSOL (ivermectin) Liquid for Horses is formulated for administration by stomach tube (nasogastric intubation) or as an oral drench. The recommended dose is 200 mcg of ivermectin per kilogram (91 mcg/lb) of body weight. Each mL contains sufficient ivermectin to treat 110 lb (50 kg) of body weight: 10 mL will treat an 1100 lb (500 kg) horse.


Use a calibrated dosing syringe inserted into the bottle to measure the appropriate dose, or pour the IVERSOL (ivermectin) Liquid into a graduated cylinder for dose measurement. Use a clean syringe if accessing the bottle to avoid contaminating the remaining product.

Administration by stomach tube (gravity or positive flow): The recommended dose can be used undiluted or diluted up to 40 times with clean tepid water (see Notes to Veterinarian). Use tepid water to flush any drug remaining in the tube into the horse’s stomach.

Administration by drench: For administration by this method, an undiluted dose is usually preferred. Clear the horse’s mouth of any food material, elevate the horse’s head, and using a syringe, deposit the appropriate dose in the back of the mouth. In order to avoid unnecessary coughing or the potential for material to enter the trachea and lungs, do not use excessive pressure (squirting), do not use a large (diluted) dose volume, and do not deposit the dose in the laryngeal area. Increased dose rejection may occur if the dose is deposited in the buccal space. Keep the horse’s head elevated and observe the horse to insure the dose is retained.

Suggested Parasite Control Program

All horses should be included in a regular parasite control program with particular attention being paid to mares, foals and yearlings. Foals should be treated initially at 6 to 8 weeks of age, and routine treatment repeated as appropriate. IVERSOL (ivermectin) Liquid effectively controls gastrointestinal nematodes and bots in horses. Regular treatment will reduce the chances of verminous arteritis and colic caused by S. vulgaris. With its broad spectrum, IVERSOL (ivermectin) Liquid is well suited to be the major product in a parasite control program.

Mode Of Action

Ivermectin, one of the avermectins, kills certain parasitic roundworms and ectoparasites such as mites and lice. The avermectins are different in their action from other antiparasitic agents. This action involves a chemical that serves as a signal from one nerve cell to another, or from a nerve cell to a muscle cell. This chemical, a neurotransmitter, is called gamma-aminobutyric acid or GABA.

In roundworms, ivermectin stimulates the release of GABA from nerve endings and enhances binding of GABA to special receptors at nerve junctions, thus interrupting nerve impulses - thereby paralyzing and killing the parasite.

The enhancement of the GABA effect in arthropods such as mites and lice resembles that in roundworms except that nerve impulses are interrupted between the nerve ending and the muscle cell. Again, this leads to paralysis and death.

The principal peripheral neurotransmitter in mammals, acetylcholine, is unaffected by ivermectin. Ivermectin does not readily penetrate the central nervous system of mammals where GABA functions as a neurotransmitter.


IVERSOL (ivermectin) Liquid may be used in horses of all ages including mares at any stage of pregnancy. Stallions may be treated without adversely affecting their fertility. These horses have been treated with no adverse effects other than those noted under Notes to Veterinarian.

Residue Warning: Do not use in horses intended for human consumption.


Caution: IVERSOL (ivermectin) Liquid has been formulated specifically for use in horses only. This product should not be used in other animal species as severe adverse reactions, including fatalities in dogs, may result.

Refrain from smoking and eating when handling. Wash hands after use. Avoid contact with eyes. Keep this and all drugs out of the reach of children.

Store in a tightly closed container at room temperature.

Protect IVERSOL (ivermectin) Liquid (undiluted or diluted) from light.

For customer service contact: Med Pharmex, Inc., 2727 Thompson Creek Rd., Pomona, CA 91767.

Environmental Safety

Studies indicate that when ivermectin comes in contact with the soil, it readily and tightly binds to the soil and becomes inactive over time. Free ivermectin may adversely affect fish and certain water-borne organisms on which they feed. Do not contaminate lakes, streams, or ground water by direct application or by improper disposal of drug containers. Dispose of drug container in an approved landfill or by incineration.

Notes To Veterinarian

Swelling and itching reactions after treatment with IVERSOL (ivermectin) Liquid have occurred in horses carrying heavy infections of neck threadworm microfilariae, Onchocerca sp. These reactions were most likely the result of microfilariae dying in large numbers. Symptomatic treatment may be advisable.

Healing of summer sores involving extensive tissue changes may require other therapy in conjunction with IVERSOL (ivermectin) Liquid. Reinfection, and measures for its prevention, should also be considered.

Special consideration should be given to the effects or potential for injury from handling, restraint, and placement of the tube during administration by stomach tube. IVERSOL (ivermectin) Liquid should be administered by drench if the risks associated with tubing are of concern. Due to the consequences of improper administration (also see Dosage and Administration), IVERSOL (ivermectin) Liquid is intended for use by a veterinarian only and is not recommended for dispensing.

IVERSOL (ivermectin) Liquid in 1 to 20 and 1 to 40 dilutions with tap water has been shown to be stable for 72 hours under the conditions recommended for the product (i.e., at room temperature, in a tightly closed container, protected from light). The diluted product does not promote the growth of common organisms. However, prolonged storage of the diluted product cannot be recommended, as the effects of possible contaminants and interactions with untested materials are unknown.

Package Information

IVERSOL (ivermectin) Liquid for Horses is available in 50 mL, 100 mL or 250 mL plastic bottle. Each 100 mL bottle contains sufficient ivermectin to treat 10 - 500 kg (1100 lb) horses. Contents may be poured into a graduated cylinder for dose measurement. Alternatively, a clean syringe may be inserted directly into the bottle to draw off the appropriate dose.

Do not store above 30°C (86°F).

Manufactured by Med Pharmex Inc., Pomona, CA 91767

Net Volume:


50 mL

Rev. 11-04

100 mL

Rev. 5-05

250 mL

Rev. 5-05

CPN: 10270161

Telephone:   909-593-7875
Fax:   909-593-7862
Every effort has been made to ensure the accuracy of the Iversol 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 © 2021 Animalytix LLC. Updated: 2020-12-31