Atorvastatin

Atorvastatin
Atorvastatin, known with the product name Lipitor/Pfizer), is a member of the drug class known as statins which is used for lowering blood cholesterol. Besides alleviating plaque, this drug prevents strokes through anti-inflammatory and other mechanisms.
Atorvastatin inhibits HMG-CoA reductase which is the rate-determining enzyme located in hepatic tissue. This enzyme produces mevalonate, a small molecule used in the synthesis of cholesterol and other mevalonate derivatives. This lowers the amount of cholesterol produced which in turn lowers the total amount of LDL cholesterol. Atorvastatin was first synthesized in 1985 by Bruce Roth while working at Parke-Davis Warner-Lambert Company (now Pfizer). Lipitor is probably the top-selling drug in the world with 2008 sales of US$12.4 billion. US patent protection is scheduled to expire in June 2011. Conversely, Pfizer made an agreement with Ranbaxy Laboratories to delay the generic launch in the US until November 2011.
Medications and Prescriptions
Generic name: atorvastatin
Product Brand Name: Lipitor
Product Manufacturer: Hexal AG Germany
Atorvastatin description:
Like other statins, atorvastatin is a competitive inhibitor of HMG-CoA reductase. Yet, it is a completely synthetic compound. HMG-CoA reductase catalyzes the reduction of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) to mevalonate, which is the rate-limiting step in hepatic cholesterol biosynthesis. Inhibition of the enzyme decreases de novo cholesterol synthesis, increasing expression of low-density lipoprotein receptors (LDL receptors) on hepatocytes. This increases LDL uptake by the hepatocytes, decreasing the amount of LDL-cholesterol in the blood. Similar to other statins, atorvastatin also reduces blood levels of triglycerides and somewhat increases levels of HDL-cholesterol.
Experimental results prove that the combination of ezetimibe (Zetia) and Lipitor lowered cholesterol more effectively than Vytorin (ezetimibe + simvastatin).
Indications:
Hypercholesterolemia (heterozygous familial and nonfamilial) and mixed dyslipidemia (Fredrickson types IIa and IIb) to reduce total cholesterol, LDL-C, apo-B, Triglycerides levels, and CRP and increase HDL levels.
Heterozygous familial hypercholesterolemia in pediatric patients
Homozygous familial hypercholesterolemia
Hypertriglyceridemia (Fredrickson Type IV)
Primary dysbetalipoproteinemia (Fredrickson Type III)
It has also been used in the treatment of combined hyperlipidemia.
Prophylaxis for myocardial infarction, stroke, unstable angina, and revascularization.*prophylaxis in patients with multiple risk factors without evident CHD.
Myocardial infarction and stroke prophylaxis in patients with type II diabetes.
Concomitant Therapy Considerations
Atorvastatin may be combined with bile acid resins. It is not advisable to combine statin treatment with fibrates due to the increased risk of myopathy related adverse reactions[6].Drug dose must be adjusted according to age of patient, and must be lowered in Hepatic insufficiency
Contraindications:
Active liver diseases such as cholestasis, hepatic encephalopathy, hepatitis, and jaundice.
Unexplained elevations in AST or ALT levels
Pregnancy.
Breast-feeding.
Preventive measures must be taken when treating with atorvastatin, as rarely it may lead to rhabdomyolysis. Itt may be very serious leading to acute renal failure due to myoglobinuria. Atorvastatin therapy should be discontinued immediately if rhabdomyolysis is suspected or diagnosed,. Also Atorvastatin should be discontinued if a patient has markedly elevated CPK levels or if a myopathy is suspected or diagnosed. The possibility of developing a myopathy is increased by the co-administration of cyclosporine, fibric acid derivatives, erythromycin, niacin, and azole antifungals
Extremely contraindicated in pregnancy, Atorvastatin is anticipated to cause harm to fetal development because of the importance of cholesterol and various products in the cholesterol biosynthesis pathway for fetal development, including steroid synthesis and cell membrane production. It is not recommended for nursing mothers due to the possibility of adverse reactions in nursing infants. Experiments with rats indicate that atorvastatin is likely to be secreted into human milk
How supplied:
Marketed by Pfizer, Atorvastatin calcium tablets are available under the trade name Lipitor, in tablets (10, 20, 40 or 80 mg) for oral administration. Tablets appear in white, elliptical, and film coated. Pfizer also packages the drug in combination with other drugs, such as is the case with its Caduet. In some countries, atorvastatin calcium is prepared in tablet form by generic drug makers under various brand names including Atoris, Atorlip, Lipvas, Sortis, Torvast, Torvacard, Totalip, and Tulip.
Side effects:
Myopathy with elevation of creatinine kinase (CK) and rhabdomyolysis are the most serious, though rare <1%. the most common side effect is headache, occurring in more than 10% of patients.
Side effects that occur in 1-10% of patients taking atorvastatin include:
Weakness, Insomnia and dizziness, chest pain and peripheral edema, rash, abdominal pain, constipation, diarrhea, dyspepsia, flatulence, nausea, urinary tract infection, arthralgia, myalgia, back pain, arthritis, sinusitis, pharyngitis, bronchitis, rhinitis, infection, flu-like syndrome and allergic reaction. In some cases, elevation of alanine transaminase (ALT) and aspartate transaminase AST) has been described.
Other very rare side effects occurring in less than 1% of patients are alopecia, deafness, dyspnea, erythema multiforme, esophagitis, facial paralysis, anaphylaxis, angina, hepatitis, hyperkinesia, impotence, migraine, myasthenia, myositis, nephritis, angioneurotic edema, arrhythmia, bullous rashes, cholestatic jaundice, , glaucoma, gout, hypotension, pruritus, rectal hemorrhage, rhabdomyolysis, somnolence, Stevens-Johnson syndrome, pancreatitis, paresthesia, peripheral neuropathy, petechiae, photosensitivity, postural syncope, tendinous contracture, thrombocytopenia, tinnitus, torticollis, toxic epidermal necrolysis, urticaria, vaginal hemorrhage, and vomiting.



Atorvastatin notes:
Atorvastatin, known with the brand name Lipitor, is an oral medication prescribed for lowering cholesterol levels in the blood. Belonging to the class of drugs referred to as statins, Atorvastatin also stabilizes plaque and prevents strokes through anti – inflammatory mechanisms. All statins, including Atorvastatin, prevent the production of cholesterol in the liver by blocking HMG-CoA reductase, an enzyme that makes cholesterol.
Approved by FDA, Atorvastatin reduces the concentration of triglycerides in the blood and raises the concentrations of HDL cholesterol, which is known to be the “good” blood cholesterol. Atorvastatin has rapid oral absorption with an approximate time to maximum plasma concentration of 1–2 hours.
When treating with atorvastatin, necessary precaution must be taken, as it may lead to rhabdomyolysis, which may be very serious leading to acute renal failure due to myoglobinuria. Atorvastatin therapy should be discontinued immediately, if rhabdomyolysis is suspected or diagnosed. If a patient has markedly elevated CPK levels or if a myopathy is suspected or diagnosed, Atorvastatin should be discontinued. As elderly patients show a greater pharmacodynamic response to Atorvastatin at any dose, they may have lower effective doses. It has also been used in the treatment of combined hyperlipidemia and is absolutely contraindicated in the case of pregnancy due to the possibility of adverse reactions.