Famotidine-associated mental confusion in elderly patients

Area of Science:

• Pharmacology
• Geriatric Medicine
• Neuroscience

Background:

• Central nervous system (CNS) effects like confusion and hallucinations are known adverse reactions associated with H2-receptor antagonists, including cimetidine and ranitidine.
• Elderly individuals, particularly those with compromised renal or hepatic function, are recognized as a more vulnerable population for these neurological side effects.

Observation:

• This report details two instances of reversible mental confusion observed in elderly patients.
• These episodes occurred following the administration of intravenous famotidine and were associated with mild renal insufficiency.

Findings:

• The observed mental confusion in these cases was reversible, suggesting a transient effect.
• The potential mechanism proposed involves increased blood-brain barrier permeability in patients with diminished renal function, leading to greater central nervous system exposure to famotidine.

Implications:

• These findings highlight a potential neurotoxic risk of intravenous famotidine in elderly patients with renal impairment.
• Clinicians should exercise caution when prescribing intravenous famotidine to elderly patients with even mild renal insufficiency.
• Further research into the pharmacokinetics and neurotoxicity of famotidine in renally impaired elderly populations is warranted.