Mechanism

Atorvastatin competitively inhibits 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. [2] By preventing the conversion of HMG-CoA to mevalonate, statins reduce cholesterol production in the liver. Atorvastatin also increases the number of LDL receptors on the surface of liver cells.what is atorvastatin

In patients with homozygous or heterozygous familial hypercholesterolemia, mixed dyslipidemia, isolated hypertriglyceridemia, or nonfamilial hypercholesterolemia, atorvastatin has been shown to reduce total Cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apo B), very-low-density lipoprotein (VLDL-C) and triglycerides (TG), while increasing HDL Cholesterol (HDL-C).

In patients with dysbeta lipoproteinemia, atorvastatin has been shown to reduce intermediate density lipoprotein (IDL-C).

Pharmacokinetics

The pharmacokinetic properties of atorvastatin are described below. [3]

absorb

Atorvastatin is rapidly absorbed after oral administration, with peak plasma concentrations occurring within 1 to 2 hours. Bioavailability is as low as 14% due to extensive first-pass metabolism.

distribute

Atorvastatin is highly bound to plasma proteins (over 98%) and has a volume of distribution of approximately 380 liters.

metabolism

Atorvastatin is metabolized by cytochrome P450 3A4 (CYP3A4) to active ortho- and para-hydroxylated metabolites.

excretion

Atorvastatin and its metabolites are eliminated in bile. Atorvastatin is not known to undergo enterohepatic recirculation. The half-life of atorvastatin is about 14 hours, and the half-life of its active metabolite is about 20-30 hours.
administrative

Atorvastatin is available as atorvastatin calcium tablets in strengths of 10, 20, 40 and 80 mg.

This medication can be taken with or without food and should be taken at the same time each day. It is usually recommended to take statins at bedtime because endogenous cholesterol synthesis is cyclical, with highest levels on an empty stomach and at night. However, atorvastatin has a longer half-life than other statins with shorter half-lives (such as lovastatin, fluvastatin, and simvastatin), allowing greater flexibility in timing of dosing.