Home › Compound Library › Simvastatin (Zocor)

Simvastatin (Zocor)

Statinprescriptionoral · predicted

Lipophilic prodrug (lactone form) hydrolyzed to active beta-hydroxy acid by hepatic CES1 and paraoxonases. Potent HMG-CoA reductase inhibitor with extensive first-pass metabolism (~5% bioavailability). CYP3A4-dependent, significant interactions with strong 3A4 inhibitors (contraindicated with itraconazole, clarithromycin). FDA limits dose to 20 mg with amlodipine and 10 mg with amiodarone/verapamil due to myopathy risk. Take in evening (cholesterol synthesis peaks at night).

Projected serum levels — 20 mg, once daily

Simvastatin (Zocor) (precursor)
Simvastatin (Zocor) modeled serum levels, 20 mg once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 0.50 1 1.5 2 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1

Maintenance schedule: 20 mg once daily (oral).

Modeled steady state after ~1 days: peak ≈ 0.49 mg, trough ≈ 0.000 mg body load. Population-based estimate over 15 days for a 20 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Statin
Route modeled
Oral
Model confidence
predicted
Half-life
2 h
Common dose
20 mg
Suggested maximum
40 mg/day
Reference dose range
5–40 mg (single dose)
Suggested cadence
once daily
Validated against
40 mg oral — Cmax 0.010 mg/L at 1.5 h

Documented interactions

  • contraindicated
    Efavirenz (Sustiva) + Simvastatin (Zocor) CYP induction

    Efavirenz (Sustiva) inducer of CYP3A4 predicted to change Simvastatin (Zocor) AUC by ~0.19x

  • contraindicated
    Rifampin + Simvastatin (Zocor) CYP induction

    Rifampin inducer of CYP3A4 predicted to change Simvastatin (Zocor) AUC by ~0.19x

  • danger
    Carbamazepine (Tegretol) + Simvastatin (Zocor) CYP induction

    Carbamazepine (Tegretol) inducer of CYP3A4 predicted to change Simvastatin (Zocor) AUC by ~0.29x

  • danger
    Clarithromycin (Biaxin) + Simvastatin (Zocor) Potentiation

    Clarithromycin dramatically increases simvastatin exposure (up to 16-fold AUC increase). BLACK BOX warning: severe risk of statin-induced myopathy and rhabdomyolysis.

  • danger
    Diltiazem + Simvastatin (Zocor) CYP inhibition

    Diltiazem mechanism_based of CYP3A4 predicted to change Simvastatin (Zocor) AUC by ~2.24x

  • danger
    Grapefruit (whole fruit) + Simvastatin (Zocor) Potentiation

    Grapefruit irreversibly inhibits intestinal CYP3A4, increasing simvastatin AUC 5-16 fold, rhabdomyolysis risk.

Serum checks 100 modeled interaction pairings for simvastatin (zocor) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals Heart Protection Study Collaborative Group · Lancet, 2002 DOI

    Landmark trial (20,536 patients, 5 years) demonstrating simvastatin 40 mg reduced major vascular events by 24%, all-cause mortality by 13%, regardless of baseline cholesterol, establishing statin therapy for high-risk…

  2. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S) Scandinavian Simvastatin Survival Study Group · Lancet, 1994 DOI

    First statin trial to show mortality benefit: simvastatin reduced total mortality by 30% and coronary mortality by 42% in patients with existing heart disease, transforming cardiovascular medicine.

2 published studies referenced in the app, each with a plain-language summary.