From the FDA Drug Label
TREATMENT N TOTAL-C LDL-C HDL-C TG* Lower Dose Comparative Study† (Mean % Change at Week 6) Simvastatin 5 mg at night. 109 -19% -26% +10 -12% Simvastatin 10 mg at night 110 -23% -30% +12 -15%
The dosage timing of statins, such as simvastatin, is typically taken at night because the body produces most of its cholesterol at night. Taking statins in the evening helps to maximize their effectiveness in reducing cholesterol production.
From the Research
Statin Administration Timing
The timing of statin administration is crucial due to the diurnal variation in cholesterol biosynthesis, which peaks at night 1.
Rationale for Evening Administration
- Cholesterol biosynthesis is higher at night, making evening administration of statins more effective in inhibiting this process 1, 2.
- Short-acting statins should be taken in the evening to maximize their efficacy in lowering low-density lipoprotein cholesterol (LDL-C) levels 1, 3.
- The current evidence suggests that long-acting statins can be taken at any time of day, allowing for more flexibility in dosing to improve patient adherence 1, 3.
Studies on Statin Administration Timing
- A systematic review and meta-analysis found that evening administration of statins resulted in greater LDL-C lowering compared to morning administration, particularly for short-acting statins 3.
- A study on fluvastatin found that extended-release formulations can be taken in the morning or evening with similar efficacy in inhibiting cholesterol biosynthesis 4.
- Another study on rosuvastatin found that morning and evening administration had similar pharmacodynamic effects and pharmacokinetics, allowing for flexible dosing 5.
Key Findings
- The optimal time for statin administration depends on the type of statin, with short-acting statins being more effective when taken in the evening 1, 3.
- Long-acting statins can be taken at any time of day, but patient adherence should be considered when determining the dosing schedule 1, 3.
- More research is needed to confirm the current evidence and provide guidance on the optimal administration timing for different statins 1, 2.