Promazine

Description

Promazine is a propylamino phenothiazine derivative that is freely soluble in alcohol and is usually given as an injection or an oral dose of granules.

Promazine is used in horses as a pre-anesthetic agent, often in conjunction with Atropine, and it is generally accepted that the recommended dose will cause moderate sedation in most horses.

Usage

Promazine is used primarily in horses because of its tranquilizing action. It works as an anti-emetic, anti-spasmodic, and hypothermic agent, and some researchers have reported that it has anti-convulsant properties. Some veterinarians recommend its use in helping control "fractious" animals.

Promazine is also used to lower blood pressure in animals with laminitis and renal failure.

Dosage and Administration

As a tranquilizer

A veterinarian should always be involved in prescribing promazine for any particular horse.

Side Effects

In large male animals, protrusion of the penis may occur. Excitement, restlessness, sweating, trembling, and, rarely, seizures and recumbency may occur.

Precautions

Cautious use and smaller doses of promazine should be given to animals with hepatic dysfunction, cardiac disease, or general debilitation.

Intravenous injections should be made slowly.

Promazine is a prescription drug approved for use in horses and U. S. federal law restricts this drug to use by or on the lawful written or oral order of a licensed veterinarian.

Promazine would be banned in any drug-free competition. It is important to check with the individual regulatory group.

Interactions

Promazine should not be given within one month of worming with an organophosphate agent. Central nervous system depressant agents, barbiturates, narcotics, etc., may cause additive CNS depression if used with promazine. Quididine may cause additive cardiac depression if given with promazine. Antidiarrheal mixtures, such as Kaolin/pectin and antacids, may cause reduced GI absorption of oral phenothiazines.

Overdose

Massive oral overdoses should be treated by emptying the gut under the direction of a veterinarian, if possible. Doxapram has been suggested as an antagonist to the CNS depressant effects of promazine.