Drug Interactions with Atorvastatin
Metabolic Pathways and Potential Interactions
- Atorvastatin undergoes glucuronidation and is transported by OATP1B1/1B3, P-glycoprotein (P-gp), and BCRP transporters, creating potential for numerous drug interactions when medications that inhibit or induce these systems are co-administered 1
Interactions with Specific Medications
- Amiodarone, a CYP3A4 and P-gp inhibitor, can increase atorvastatin levels 1
- Diltiazem and verapamil, calcium channel blockers, inhibit CYP3A4 and can increase atorvastatin levels 1
- Sacubitril/valsartan may increase atorvastatin levels through inhibition of OATP1B1, OATP1B3, OAT1, and OAT3 transporters 1, 2
- Gemfibrozil increases atorvastatin levels through inhibition of glucuronidation and OATP1B1 1
Recommendations for Managing Interactions
- No dose adjustment is needed for atorvastatin with amiodarone, unlike simvastatin which requires dose limitation 1
- Consider lower doses of atorvastatin when used with sacubitril/valsartan 1, 2
- Review complete medication list to identify potential interactions before starting combination therapy 2
- Monitor for muscle symptoms (pain, tenderness, weakness) at 6-12 weeks and each follow-up visit during combination therapy 2
Patient Monitoring and Education
- Check liver enzymes initially, at 12 weeks, and then annually during combination therapy 2
- Measure CK if muscle symptoms develop during combination therapy 2
- Educate patients about symptoms requiring immediate medical attention when combination therapy cannot be avoided 2