Equivalent Rosuvastatin Dose for Atorvastatin 80 mg
When converting from atorvastatin 80 mg to rosuvastatin, use rosuvastatin 20-40 mg, with 20 mg being the most appropriate starting dose for most patients. 1, 2
Statin Intensity Classification
Both atorvastatin 80 mg and rosuvastatin 20-40 mg are classified as high-intensity statin therapy, defined as achieving ≥50% reduction in LDL-C from baseline. 1, 2
- Atorvastatin 80 mg produces approximately 50-55% LDL-C reduction 1
- Rosuvastatin 20 mg produces approximately 50% LDL-C reduction 2, 3
- Rosuvastatin 40 mg produces approximately 55% LDL-C reduction 3
Evidence-Based Conversion Rationale
The guideline-based conversion is straightforward: rosuvastatin 20 mg is the equivalent high-intensity dose to atorvastatin 80 mg. 1, 2
- The ACC/AHA guidelines explicitly list both atorvastatin 40-80 mg and rosuvastatin 20-40 mg as high-intensity options achieving ≥50% LDL-C reduction 1, 2
- Pharmacologic data demonstrates that rosuvastatin is approximately 3-3.5 times more potent than atorvastatin on a milligram-per-milligram basis 3
- Specifically, rosuvastatin 20 mg achieves LDL-C reductions equivalent to atorvastatin 70 mg 3
Clinical Considerations for Conversion
Start with rosuvastatin 20 mg rather than 40 mg for the following reasons:
- Rosuvastatin 20 mg provides comparable LDL-C lowering to atorvastatin 80 mg (both achieving approximately 50% reduction) 1, 3
- Safety profile favors the lower dose: atorvastatin demonstrates higher rates of adverse drug reactions compared to rosuvastatin, particularly abnormal liver transaminases (3.99% vs 1.39%) and statin-associated muscle symptoms (1.14% vs 0.5%) 4
- Rosuvastatin 40 mg may be reserved for patients who require the maximum 55% LDL-C reduction and tolerate rosuvastatin 20 mg well 3
Special Population Adjustments
Renal impairment requires dose modification:
- For patients with CrCl <30 mL/min, rosuvastatin should not exceed 10 mg daily 2
- Atorvastatin generally requires no dose adjustment for renal impairment alone 2
- If the patient has significant renal dysfunction, consider maintaining atorvastatin or using rosuvastatin 10 mg maximum 2
Monitoring After Conversion
Check lipid levels 4-12 weeks after conversion to ensure therapeutic equivalence: 2
- Verify LDL-C reduction is maintained at ≥50% from baseline
- Assess for any adverse effects, particularly muscle symptoms or liver enzyme elevations 2, 4
- Adjust dose based on LDL-C response and tolerability 2
Common Pitfalls to Avoid
- Do not use rosuvastatin 40 mg as the initial conversion dose unless the patient specifically requires maximal LDL-C lowering beyond 50% reduction, as this increases adverse event risk without proportional benefit for most patients 4, 3
- Do not forget to assess renal function before prescribing rosuvastatin, as dose limitations apply in severe renal impairment 2
- Do not assume automatic 1:1 tolerability between statins—while both are high-intensity, individual patients may experience different side effect profiles due to different metabolic pathways (atorvastatin via CYP3A4, rosuvastatin via CYP2C9) 5