Today I am writing about lipitor----It belongs to statin class of drugs which help in lowering down the cholesterol level in the body.

LIPITOR…………….the largest selling drug in the world.

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GENERIC NAME- ATORVASTATIN, marketed under the trade name lipitor is the member of the statin (cholesterol lowering drugs) class of drugs .It is an inhibitor of enzyme HMG-CoA reductase, responsible for production of cholesterol in the liver thus it reduces the cholesterol produced in the body and in turn it reduces the total amount of LDL cholesterol (low density lipoproteins –LDL, they transport cholesterol from tissue to the blood, therefore harmful for the body)

The drug is a competitive inhibitor of the enzyme. It is a synthetic lipid lowering agent ,HMG-CoA reductase converts 3-hydroxy -3-methylglutaryl-coenzyme A to mevalonate ,a precursor of sterols ,including cholesterol .Cholesterol in the liver are incorporated into LDL and are released into plasma for delivery to peripheral tissues.Higher cholesterol levels promote cardiovascular diseases.

Mevalonatepathway…… It is an important cellular metabolic pathway present in all higher eukaryotes and many bacteria. It is important for the production of dimethylallyl pyrophosphate (DMAPP) and isopentenyl pyrophosphate (IPP) that serve as the basis for the biosynthesis of molecules used in processes as diverse as protein prenylation, cell membrane maintenance, hormones, protein anchoring and N-glycosylation.

Several key enzymes can be activated through DNA transcriptional regulation on activation of SREBP (Sterol Regulatory Element-Binding Protein-1 and -2). This intracellular sensor detects low cholesterol levels and stimulates endogenous production by the HMG-CoA reductase pathway, as well as increasing lipoprotein uptake by up-regulating the LDL receptor. Regulation of this pathway is also achieved by controlling the rate of translation of the mRNA, degradation of reductase and phosphorylation.

STATINS-

The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemicagents, used as pharmaceutical agents to lower cholesterol levels in people with or at risk for cardiovascular disease. They lower cholesterol by inhibiting the enzyme HMG-CoA reductase, which is the rate-limiting enzyme of the mevalonate pathway of cholesterol synthesis. Inhibition of this enzyme in the liver stimulates LDL receptors, resulting in an increased clearance of low-density lipoprotein (LDL) from the bloodstream and a decrease in blood cholesterol levels. The first results can be seen after one week of use and the effect is maximal after four to six weeks.

ROUTE OF ADMINISTRATION – ORAL

DOSAGE FORM/STRENGTH-10, 20, 40, 80- mg, tablets

SIDE EFFECTS-

Rare cases of muscle problems and liver problems have been associated with the use of atorvastatin and other similar medicines.. These may be early symptoms of muscle or liver problems.. Alcohol and atorvastatin can both be damaging to the liver. Alcohol should be used only in moderation.

ECONOMICS-

Pfizer is the company holding the patent rights for the drug, earning huge profits from it, the drug is expected to hit $13 billion mark this year.

Ranbaxy lost the legal case to produce the generic version of the drug. The Pfizer holds the U.S, patent for the drug till 2010.

Latest update-

According to the recent studies it is visible that this class of the drugs is not as much effective as they are projected by the large Pharma companies. The statins reduce heart attack risks but they are having side effects…. which can’t be ignored. (Business week, The Economic times)