A rare debilitating neurological adverse effect of ranolazine due to drug interaction with clarithromycin

Area of Science:

• Pharmacology
• Clinical Toxicology
• Geriatric Medicine

Background:

• Medication errors are a significant concern in healthcare, potentially occurring at any patient care stage.
• Drug interactions are well-documented, particularly involving macrolide antibiotics and ranolazine.
• These interactions often involve the cytochrome P4503A (CYP3A) metabolic pathway.

Observation:

• A case involving an elderly patient experiencing rare, debilitating neurological adverse effects is presented.
• The adverse effects were linked to the administration of ranolazine.
• The patient's medication regimen included clarithromycin, a macrolide antibiotic.

Findings:

• A significant drug interaction occurred between clarithromycin and ranolazine.
• This interaction led to previously undocumented, severe neurological adverse effects in the elderly patient.
• The interaction's mechanism is primarily attributed to the inhibition of the CYP3A metabolic pathway.

Implications:

• Highlights the critical need for careful medication review in elderly patients, especially those with polypharmacy.
• Underscores the potential for severe adverse events due to drug-drug interactions involving CYP3A substrates.
• Emphasizes the importance of recognizing and managing drug interactions to prevent patient harm.