Atorvastatin is the #1 most prescribed drug in the USA — 115 million Rx/yr. This 2026 complete guide covers HMG-CoA mechanism, 10mg vs 40mg vs 80mg AHA guideline intensity table, when rhabdomyolysis is a real concern vs not, why grapefruit raises levels 83%, the Mavyret HCV interaction requiring a statin holiday, atorvastatin vs rosuvastatin table, and why it must be taken indefinitely.