Cimetidine kinetics during resuscitation from burn shock

Area of Science:

• Pharmacokinetics
• Burn Medicine
• Critical Care

Background:

• Severely burned patients experience significant metabolic and hemodynamic shifts.
• These changes can profoundly affect how drugs are processed (drug kinetics).
• Cimetidine is frequently used to prevent stress erosions in burn patients.

Purpose of the Study:

• To investigate the pharmacokinetic changes of cimetidine during fluid resuscitation in severely burned patients.
• To compare cimetidine clearance and drug recovery before and after fluid resuscitation completion.

Main Methods:

• Studied cimetidine pharmacokinetics in 11 severely burned patients (mean burn size 45% TBSA).
• Collected data during early post-burn fluid resuscitation and after resuscitation completion.
• Measured total clearance, volume of distribution, half-life, renal and non-renal clearance, and urinary drug recovery.

Main Results:

• Total clearance, volume of distribution, and half-life of cimetidine remained consistent.
• Renal clearance of cimetidine was lower, and non-renal clearance was higher during fluid resuscitation compared to post-resuscitation.
• Urinary recovery of unchanged cimetidine decreased significantly during resuscitation (50.7%) versus post-resuscitation (81.0%).

Conclusions:

• Fluid resuscitation in severe burns alters cimetidine clearance pathways, favoring non-renal routes.
• This shift reduces the amount of active drug recovered unchanged in urine.
• Findings suggest potential implications for cimetidine dosing and efficacy in critically ill burn patients.