There are seven currently prescribed forms of statin drugs in the US. The most heavily advertised one is rosuvastatin, which is sold by the pharmaceutical company AstraZeneca under the name of Crestor. It was approved for sale in the United States in 2003, and is available in 5, 10, 20 or 40 mg. tablets to be taken once daily. While acknowledged as a powerful statin, Crestor has recently been criticized for not being thoroughly investigated before entering the drug market. Crestor is still under patent - there is no generic form available and won't be for years - so it is expensive. Attempts by the manufacturer to establish its clear superiority over other statins (which are available as generics) has fallen flat. CAS (Chemical Abstracts Service) abstract number is 287714-41-4. More on rosuvastatin.
Atorvastatin was developed by Pfizer and sold under the name of Lipitor. Pfizer owned the patent until expiration in November 2011, at which time generic forms of this medicine became available.. Lipitor is 100% synthetic, unlike some statins which are derived from fungus. Atorvastatin may also be used to reduce triglycerides as well as reducing blood pressure and lowering LDL levels. It is taken once per day in a dosage level decided by a doctor. (CAS number is 134523-00-5.) It is estimated that 21% of statin prescriptions in the US are for atorvastatin. (http://www.nejm.org/doi/full/10.1056/NEJMp1113112) More on atorvastatin.
Simvastatin, which was developed by Merck and Co. and sold by the name of Zocor, and now available in generic form. Many manufacturers make it and about half of all statin pills sold in the United States are simvastatin. One of the first blockbuster statins, simvastatin was approved by the FDA in 1991, and can be prescribed for patients 10 years of age and older. It is a HMG-CoA enzyme inhibitor like all statins. Some people should not take Zocor, including those with allergies to the following inactive ingredients in Zocor: celluslose, lactose, magnesium stearate, iron oxides, talc, titanium dioxide and starch. More on simvastatin. (CAS number is 79902-63-9.)
Pravastatin, a statin drug manufactured by Bristol-Meyers Squibb and sold under the name Pravachol or Pravigard, is an enzyme blocker that is derived from a mold called Nocardia autotrophica. It can be prescribed for patients as young as eight years of age, and was approved by the FDA in 1991. Pravachol and Pravigard are taken in tablet form once daily, and like all statins should be combined with a low-fat, low-cholesterol diet for maximum effectiveness. More on pravastatin. (CAS number is 81093-37-0.)
Fluvastatin, which is produced by Novartis and sold under the name Lescol or Lescol XL, was first approved by the FDA in 1993. Lescol is one of the milder statin drugs, and can be combined with therapeutic lifestyle changes (such as a low-fat diet or increased exercise) to lower LDL cholesterol levels. It is available in capsule form or in extended-release tablet to be take orally once or twice a day at night. More on fluvastatin. (CAS number is 93957-54-1.)
Lovastatin, which is prescribed under the names Mevacor, Advicor or Altoprev and manufactured by Merck and Co., was first approved in 1987. It is derived from Aspergillus terreus, and is used in tandem with diet changes (particularly the restriction of fat and cholesterol intake) in order to reduce amounts of cholesterol and other fatty substances in the blood. Mevacor is prescribed as either a normal tablet or an extended-release tablet to be taken orally once or twice a day with meals. Meals should low-cholesterol and low-fat, and large amounts of grapefruit juice (more than one quart a day) should be avoided while taking Mevacor. More on lovastatin and mevacor. (CAS number is 75330-75-5.)
Pitavastatin, sold under the brand name Livalo, was approved by the FDA in August 2009. It is marketed in the US by Eli Lilly. (CAS number is 147526-32-7.) It has been used in Japan since 2003 and is made by the Japanese company Kowa. The company claims pitavastatin is less liable to interactions with other drugs than competing statins. More on pitavastatin.
An eigth statin drug, cerivastatin (Baycol), was taken off the market in 2001 by its manufacturer Bayer because of its serious side-effects.
One way to classify statins is by their manufacture. Some are derived from micro-organisms through biotechnology. These are called fermentation-dericed or Type 1.
Others are made through chemical synthesis (no living organisms involved). These are synthetic, or Type 2 statins. It is common for pharmaceuticals to be made throgh fermentation and through chemical synthesis.
|Fermentation||Type 1||lovastatin, simvastatin, pravastatin, pitavastatin|
|Synthetic||Type 2||fluvastatin, atorvastatin, rosuvastatin|
The Type 1 drugs have chemical structures similar to mevastatin.
Water soluble vs Fat soluble - like most chemicals, statins are soluble in both aqueous environments and oily environments. The solubility levels differ enough that it is possible to classify some as hydrophilic (better solubiity in water) or lipophilic (better solubility in fats).
|Classification by solubility||Medicines|
|Water soluble (hydrophilic)||pravastatin, pitavastatin, and rosuvastatin|
|Fat soluble (lipophilic)||atorvastatin, fluvastatin, lovastatin and simvastatin.|
Very generally speaking, the hydrophilic statins are excreted from the body largely unmetabolized by the liver. Lipophilic statins are broken down in the liver by the cytochrome P450 (CYP450) system. Hydrophilic statins tend to have fewer interactions with other drugs.
Generics are popular partly because of their lower cost. In 2006 the patents on both pravastatin and simvastatin (Pravachol and Zoror) expired, and generic versions of these medicines hit the market. This may have contributed to the increased number of prescriptions written in the past few years. Lipitor is notoriously expensive, but the patent for atorvastatin has expired and generic forms are available. The price has not fallen much, but more generics should become available in late 2012 and maybe that will spur a price decrease.
You might often see news stories reporting that one statin is more effective than another. A group of scientists published a criticism of company-sponsored studies. They found that when pharmaceutical companies put up the money to fund the study, the results appear to be unreliable. Some of these studies were too small and were done for marketing purposes. Company-sponsored trials favor their own drug, which doesn't necessarily mean that the company's drug isn't better than the competition, but you need to look at the sources of these claims.
The US government's Agency for Healthcare Research and Quality published a detailed comparison of lipid-lowering medical treatments.