Effects of acepromazine or methadone on midazolam-induced behavioral reactions in dogs

Area of Science:

• Veterinary Pharmacology
• Animal Behavior Studies

Background:

• Midazolam is commonly used for sedation in veterinary medicine.
• Paradoxical excitement and increased activity can occur with midazolam administration in dogs.
• Investigating co-administered drugs to mitigate these side effects is crucial.

Purpose of the Study:

• To evaluate the efficacy of acepromazine or methadone in reducing midazolam-induced behavioral changes in healthy dogs.
• To assess the impact of these combinations on overall excitement and activity levels.

Main Methods:

• Healthy dogs received intramuscular midazolam alone, or combined with methadone or acepromazine, or saline control.
• Blinded observers assessed behavioral parameters via video recordings.
• Accelerometry measured total activity counts (TAC) pre- and post-treatment.

Main Results:

• Midazolam administration, with or without acepromazine or methadone, resulted in increased post-treatment excitement compared to baseline or saline.
• Significant increases in pacing, restlessness, chewing/licking, and sniffing were observed in midazolam-treated groups.
• No significant differences in total activity counts (TAC) were detected between groups post-treatment.

Conclusions:

• Acepromazine and methadone failed to prevent or reduce midazolam-induced paradoxical excitement and behavioral alterations in healthy dogs.
• Midazolam can cause excitation, panting, pacing, restlessness, licking/chewing, and vocalization, which are not mitigated by co-administration with acepromazine or methadone.