Hypotension in the horse induced by acepromazine maleate.

The research examines the impact of acepromazine maleate on blood pressure in horses, demonstrating that both the dosage and administration method affect the degree and duration of hypotension (low blood pressure). Intravenous delivery of the drug was found to be faster acting than intramuscular injection, and larger doses kept blood pressure low for a longer period.

Investigation into the Hypotensive Effect of Acepromazine Maleate

The paper explores the effect of a drug called acepromazine maleate on a horse’s blood pressure. The researchers discovered that:

• The hypotensive effect (i.e., causing low blood pressure) of the drug acepromazine maleate is linked to both the dosage given and the way it is administered.
• The decreased blood pressure varied amongst individual horses, indicating that different animals reacted differently to the drug.

Impact of Method of Administration and Dosage

The research also scrutinised the impact of two different methods of administering the drug, intravenously (directly into the bloodstream) and intramuscularly (into the muscle), finding that:

• Intravenous administration produced a more immediate maximum effect than intramuscular injection.
• The larger the dose administered, the longer the animal’s blood pressure stayed at low levels. This effect was measured on six different horses and remained significantly below control values for more than six hours after an intramuscular injection of 0.05 mg acepromazine maleate per kg of body weight.

Respiratory Rate and Body Temperature Observations

Other important observations made during the experiment include:

• The respiratory rate notably decreased when the drug was administered, with the length but not the degree of this slow breathing (bradypnoea) associated with the dose given.
• A minor, transient drop in body temperature was observed after the drug was administered.

Heart Rate Effects

Despite these significant findings, the researchers found that:

• The heart rate was not significantly altered by the administration of acepromazine maleate, indicating that while the compound had substantial impacts on blood pressure and respiratory rate, it had no noticeable effect on cardiac rhythm.