Pharmacy Clinical Pearl of the Day: Statins and Drug Interactions

Several obvious interactions with statins to always remember:

• Older drugs such as lovastatin (Mevacor, Altoprev), simvastatin (Zocor), and atorvastatin (Lipitor) have the most drug interactions. They may interact with:
  • Antibiotics, such as erythromycin (Ery-Ped, Ery-tab)
  • Antifungal drugs, such as ketoconazole (Xolegel, Extina, Nizoral)
  • HIV drugs, such as protease inhibitors

Some drugs for heart disease can also cause interactions, including:

• Amiodarone (Cordarone, Pacerone)
• Diltiazem (Cardizem)
• Verapamil (Calan, Verelan)
• Niacin (Niaspan)

These drugs also interact with grapefruit juice, but to different degrees depending on which agent.

Explanation

Statins have important drug interactions that should be monitored. Some of these interactions involve the enzymes responsible for the elimination of statins by the liver, especially with liver enzymes such as P-450.

Drugs that block this enzyme also block elimination of the statins, thereby increasing the levels in the blood, which can lead to rhabdomyolysis.

Reference

• Statins: Drug List, Names (Brand & Generic) & Side Effects (medicinenet.com)