Altered hydroxydesipramine concentrations in elderly depressed patients

Area of Science:

• Pharmacology
• Geriatrics
• Drug Metabolism

Background:

• Hydroxy metabolites of desipramine (DMI), such as 2-hydroxydesipramine (2-OH-DMI), possess pharmacologic activity.
• These metabolites are not solely responsible for side effects and may contribute to therapeutic effects.

Purpose of the Study:

• To determine the ratio of 2-hydroxydesipramine (2-OH-DMI) to desipramine (DMI) in patients at steady state.
• To investigate age-related differences in this ratio and the underlying pharmacokinetic factors.

Main Methods:

• Blood samples were collected from patients treated with DMI to measure drug and metabolite levels.
• Steady-state concentrations of DMI and 2-OH-DMI were analyzed.
• Urinary clearance and plasma levels were assessed in relation to patient age.

Main Results:

• The ratio of 2-OH-DMI to DMI was significantly higher in elderly patients compared to younger patients.
• Plasma levels of 2-OH-DMI increased with advancing age.
• Urinary clearance of 2-OH-DMI decreased with age.

Conclusions:

• Age-related changes in renal function, specifically decreased glomerular filtration, likely contribute to the elevated plasma concentrations of 2-OH-DMI in the elderly.
• These findings highlight the importance of considering metabolite pharmacokinetics in different age groups for DMI therapy.