Decrease in the time-dependent difference in urinary excretion of furosemide with age

Area of Science:

• Pharmacokinetics
• Chronopharmacology
• Gerontology

Background:

• Furosemide is a loop diuretic used to treat fluid retention.
• Age can influence drug metabolism and excretion.
• Circadian rhythms affect physiological processes, including drug response.

Purpose of the Study:

• To investigate the influence of aging on the time-dependent urinary excretion of furosemide.
• To determine if age affects the circadian rhythm of furosemide excretion in male Wistar rats.

Main Methods:

• Longitudinal study involving male Wistar rats aged 3 to 21 months.
• Furosemide administered orally at 12:00 h (day) and 00:00 h (night).
• Urine collected for 8 hours post-dosage; excretion levels analyzed.

Main Results:

• Urinary furosemide excretion was significantly higher in the day trial compared to the night trial at 3 months of age.
• This time-dependent difference persisted up to 15 months of age.
• The difference in excretion between day and night trials diminished with age, disappearing by 18 months.

Conclusions:

• A significant time-dependent difference in furosemide urinary excretion exists in younger rats.
• Aging leads to a gradual reduction and eventual loss of this time-dependent difference.
• By 18 months of age, male Wistar rats no longer show a circadian variation in furosemide excretion.