Moderate
Atorvastatin × Digoxin
HMG-CoA reductase inhibitors (statins)×Cardiac glycosides (digitalis)
Mechanism
Atorvastatin blocks intestinal P-glycoprotein (one of the digoxin clearance routes). Digoxin plasma levels rise by about 20%.
Symptoms
Nausea, anorexia, visual disturbances (yellow-green halos around lights), arrhythmias. Older patients: confusion.
Management
After starting atorvastatin, check digoxin level at 2–4 weeks. If it rises above target, reduce digoxin by 25%.