Appropriate Rosuvastatin Replacement Dosing for Atorvastatin 20 mg
For a patient currently taking atorvastatin 20 mg daily, the appropriate replacement dose is rosuvastatin 5-10 mg daily, with the specific dose determined by renal function and cardiovascular risk status. 1
Statin Intensity Equivalence
- Atorvastatin 20 mg is classified as moderate-intensity statin therapy, achieving 30-49% LDL-C reduction. 1
- Rosuvastatin 5-10 mg provides equivalent moderate-intensity therapy with comparable LDL-C lowering. 1
- The dose-to-dose potency of rosuvastatin is approximately 2-fold higher than atorvastatin, meaning lower milligram doses of rosuvastatin achieve similar lipid-lowering effects. 2, 3
Dosing Algorithm Based on Clinical Context
For patients WITHOUT severe renal impairment (CrCl ≥30 mL/min):
- Start with rosuvastatin 10 mg daily as the standard equivalent replacement for atorvastatin 20 mg. 1
- This maintains moderate-intensity therapy and achieves approximately 46-48% LDL-C reduction. 2, 4
For patients WITH severe renal impairment (CrCl <30 mL/min):
- Start with rosuvastatin 5 mg daily and do NOT exceed 10 mg daily. 1, 5, 6
- Rosuvastatin plasma concentrations increase 2-fold in severe renal impairment, necessitating dose restriction to prevent myopathy. 6, 7
- In contrast, atorvastatin requires no dose adjustment for renal impairment alone, making it potentially preferable to continue atorvastatin rather than switch in this population. 5
For patients with Stage 4 CKD (eGFR 15-29 mL/min/1.73 m²):
- Consider maintaining atorvastatin rather than switching to rosuvastatin, as atorvastatin can be dosed from 10-80 mg daily without modification regardless of kidney function severity. 5
- If switching is necessary, use rosuvastatin 5 mg daily maximum 10 mg daily. 5, 6
Critical Renal Function Considerations
A common pitfall is failing to assess renal function before conversion. 1
- Rosuvastatin has significant renal excretion and requires dose limitation when CrCl <30 mL/min/1.73 m². 5, 6
- Atorvastatin has minimal renal excretion (<2%) and is the preferred statin for advanced CKD. 5
- For patients approaching dialysis or with eGFR <30 mL/min/1.73 m², maintaining atorvastatin is operationally simpler and safer than converting to rosuvastatin. 5
Post-Conversion Monitoring
- Reassess lipid panel 4-12 weeks after conversion to ensure equivalent LDL-C reduction is maintained. 1, 6
- Adjust dose based on LDL-C response, tolerability, and cardiovascular risk status. 1
- Not monitoring lipid levels after conversion is a common pitfall that can result in inadequate lipid control or missed opportunities for dose optimization. 1
Drug Interaction Considerations
- Rosuvastatin has minimal cytochrome P450 metabolism, resulting in fewer drug interactions compared to atorvastatin. 3, 4
- Both rosuvastatin and atorvastatin are substrates for OATP1B1 transporter, making them susceptible to interactions with cyclosporine and other immunosuppressants. 8
- If the patient is taking cyclosporine, tacrolimus, everolimus, or sirolimus, rosuvastatin should be limited to 5 mg daily maximum. 8
Special Population Adjustments
Asian patients:
- Start with rosuvastatin 5 mg daily regardless of renal function due to 2-fold higher plasma concentrations in this population. 6
Patients on dialysis:
- Do not initiate rosuvastatin in dialysis-dependent patients, as major trials (AURORA) showed no cardiovascular benefit. 5, 6
- If already taking atorvastatin when dialysis begins, continue it rather than switching. 5
When Higher Intensity Therapy is Needed
- If the patient requires escalation to high-intensity therapy (≥50% LDL-C reduction), rosuvastatin 20 mg would be the appropriate dose. 1, 6
- However, in severe renal impairment (CrCl <30 mL/min), rosuvastatin cannot exceed 10 mg daily, making atorvastatin 40-80 mg the preferred option for high-intensity therapy in this population. 5, 6