Acetaminophen as a postsurgical analgesic in rats: a practical solution to neophobia

Area of Science:

• Veterinary Medicine
• Pharmacology
• Animal Behavior

Background:

• Acetaminophen is increasingly used as a postsurgical analgesic in rodent research.
• Concerns exist regarding suboptimal dosing due to taste neophobia in rodents.
• Developing effective administration protocols is crucial for postsurgical care.

Purpose of the Study:

• To investigate the presence, duration, and extent of acetaminophen-induced taste neophobia in rats.
• To inform the development of optimal protocols for postsurgical acetaminophen administration in rodent labs.

Main Methods:

• Adult male and female Long Evans rats (n=32) underwent a 7-day baseline monitoring period.
• Cherry-flavored acetaminophen (6 mg/ml) was administered in drinking water for 7 days.
• Fluid and food consumption, and body weight were continuously monitored.

Main Results:

• Male rats exhibited a 1-day period of reduced fluid intake, followed by increased consumption.
• Female rats maintained normal to elevated fluid consumption throughout the study.
• Both sexes showed decreased food intake and subsequent weight loss during acetaminophen exposure.

Conclusions:

• Acetaminophen taste neophobia is present in rats, with sex-specific variations in fluid intake.
• Reduced food intake and weight loss indicate physiological effects beyond taste aversion.
• Careful consideration of administration methods is required for effective postsurgical analgesia with acetaminophen in rodents.