Adults

Initial dose is typically 10 mg or 20 mg once daily. Dosage range is 10 mg to 80 mg once daily. Doses should be individualized based on LDL-C levels and patient response.

Elderly

No dosage adjustment required for elderly patients.

Renal_impairment

No dosage adjustment required for patients with renal impairment.

Onset

Significant lipid-lowering effects typically observed within 2 weeks, with maximum effects seen after 4 weeks.

Excretion

Primarily excreted in the bile following hepatic and/or extrahepatic metabolism. Less than 2% of the dose is recovered in urine.

Half life

The apparent plasma elimination half-life of atorvastatin is approximately 14 hours, but the half-life of HMG-CoA reductase inhibitory activity is 20-30 hours due to active metabolites.

Absorption

Rapidly absorbed after oral administration, with peak plasma concentrations occurring within 1-2 hours. Absolute bioavailability is approximately 14%.

Metabolism

Extensively metabolized by cytochrome P450 3A4 (CYP3A4) to active ortho- and parahydroxylated metabolites and inactive beta-oxidation products.

0

Strong CYP3A4 inhibitors (e.g., cyclosporine, telithromycin, clarithromycin, HIV protease inhibitors, itraconazole, ketoconazole, nefazodone, voriconazole, posaconazole) may significantly increase atorvastatin plasma concentrations and the risk of myopathy.

1

Gemfibrozil, other fibrates, or niacin (at lipid-modifying doses) can increase the risk of myopathy/rhabdomyolysis when co-administered with statins.

2

Colchicine: Concomitant use with atorvastatin may increase the risk of myopathy, including rhabdomyolysis.

3

Oral Contraceptives: Atorvastatin may increase plasma concentrations of ethinyl estradiol and norethindrone.