Atorvastatin: Statin medication

Atorvastatin, sold under the trade name Lipitor among others, is a statin medication used to prevent cardiovascular disease in those at high risk and treat abnormal lipid levels. For the prevention of cardiovascular disease statins are a first line treatment. It is taken by mouth.
For the prevention of cardiovascular disease statins are a first line treatment




Common side effects include joint pain, diarrhea, heart burn, nausea, and muscle pains. Serious side effects may include rhabdomyolysis, liver problems, and diabetes. Use during pregnancy may harm the baby. Like all statins, atorvastatin works by inhibiting HMG-CoA reductase, an enzyme found in liver that plays a role in producing cholesterol.

Atorvastatin was approved for medical use in the United States in 1996. It is available as a generic medication. In the United States the wholesale cost per month is about 3.80 USD as of 2018. In the United Kingdom it costs the NHS about £0.70 per month as of 2018. In 2016 it was the 3rd most prescribed medication in the United States with more than 96 million prescriptions.

Dyslipidemia

  • 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 as well as increase HDL levels.
  • Heterozygous familial hypercholesterolemia in children
  • Homozygous familial hypercholesterolemia
  • Hypertriglyceridemia (Fredrickson Type IV)
  • Primary dysbetalipoproteinemia (Fredrickson Type III)
  • Combined hyperlipidemia

Cardiovascular disease

  • Primary prevention of heart attack, stroke, and need for revascularization procedures in people who have risk factors such as age, smoking, high blood pressure, low HDL-C, and a family history of early heart disease, but have not yet developed evidence of coronary artery disease.
  • Secondary prevention of myocardial infarction, stroke, unstable angina, and re-vascularization in people with established coronary artery disease.
  • Myocardial infarction and stroke prevention in people with type II diabetes. Studies suggest that high-dose statin therapy may play a plaque-stabilizing role in people with acute coronary syndrome and thrombotic stroke.

Administration

Atorvastatin may be used in combination with bile acid sequestrants and ezetimibe to increase the reduction in cholesterol levels. However, It is not recommended to combine statin medication treatment with certain other cholesterol-lowering medications, particularly fibrates, because this may increase the risk of myopathy-related adverse effects.

While many statin medications should be administered at bedtime for optimal effect, atorvastatin can be dosed at any time of day, as long as it is continually dosed once daily at the same time.

Specific populations
  • Geriatric: Plasma concentrations of atorvastatin in healthy elderly subjects are higher than those in young adults, and clinical data suggests a greater degree of LDL-lowering at any dose for people in the population as compared to young adults.
  • Pediatric: Pharmacokinetic data is not available for this population.
  • Gender: Plasma concentrations are generally higher in women than in men, but there is no clinically significant difference in the extent of LDL reduction between men and women.
  • Kidney impairment: Kidney disease has no influence on plasma concentrations of atorvastatin and dosing need not be adjusted in these people.
  • Hemodialysis: Hemodialysis will not significantly alter medication levels or change clinical effect of atorvastatin.
  • Hepatic impairment: In people with chronic alcoholic liver disease, levels of atorvastatin may be significantly increased depending upon the extent of liver disease.

Uses

Atorvastatin is used along with a proper diet to help lower "bad" cholesterol and fats (such as LDL, triglycerides) and raise "good" cholesterol (HDL) in the blood. It belongs to a group of drugs known as "statins." It works by reducing the amount of cholesterol made by the liver. Lowering "bad" cholesterol and triglycerides and raising "good" cholesterol decreases the risk of heart disease and helps prevent strokes and heart attacks.

In addition to eating a proper diet (such as a low-cholesterol/low-fat diet), other lifestyle changes that may help this medication work better include exercising, losing weight if overweight, and stopping smoking. Consult your doctor for more details.

How to use Atorvastatin

Read the Patient Information Leaflet if available from your pharmacist before you start taking atorvastatin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth with or without food as directed by your doctor, usually once
daily.

The dosage is based on your medical condition, response to treatment, age, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor instructs you otherwise. Grapefruit can increase the amount of this medication in your bloodstream. Consult your doctor or pharmacist for more details.

If you also take certain other drugs to lower your cholesterol (bile acid-binding resins such as cholestyramine or colestipol), take atorvastatin at least 1 hour before or at least 4 hours after taking these medications. These products can react with atorvastatin, preventing its full absorption.

Take this medication regularly in order to get the most benefit from it. Remember to take it at the same time each day. It is important to continue taking this medication even if you feel well. Most people with high cholesterol or triglycerides do not feel sick.

It is very important to continue to follow your doctor's advice about diet and exercise. It may take up to 4 weeks before you get the full benefit of this drug.

Contraindications

  • Active liver disease: cholestasis, hepatic encephalopathy, hepatitis, and jaundice
  • Unexplained elevations in AST or ALT levels
  • Pregnancy: Atorvastatin may cause fetal harm by affecting serum cholesterol and triglyceride levels, which are essential for fetal development.
  • Breastfeeding: Small amounts of other statin medications have been found to pass into breast milk, although atorvastatin has not been studied, specifically. Due to risk of disrupting a breastfeeding infant's metabolism of lipids, atorvastatin is not regarded as compatible with breastfeeding.
  • Markedly elevated CPK levels or if a myopathy is suspected or diagnosed after dosing of atorvastatin has begun. Very rarely, atorvastatin may cause rhabdomyolysis, and it may be very serious leading to acute renal failure due to myoglobinuria. If rhabdomyolysis is suspected or diagnosed, atorvastatin therapy should be discontinued immediately.
  • The likelihood of developing a myopathy is increased by the co-administration of cyclosporine, fibric acid derivatives, erythromycin, niacin, and azole antifungals.
Mechanism of action

As with other statins, atorvastatin is a competitive inhibitor of HMG-CoA reductase. Unlike most others, however, 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. Like other statins, atorvastatin also reduces blood levels of triglycerides and slightly increases levels of HDL-cholesterol.

Recent studies have shown that in people with acute coronary syndrome, high-dose statin treatment may play a plaque-stabilizing role. At high doses, statins have anti-inflammatory effects, incite reduction of the necrotic plaque core, and improve endothelial function, leading to plaque stabilization and, sometimes, plaque regression.

However, there is an increased risk of statin-associated adverse effects with such high-dose statin treatment. There is a similar thought process and risks associated with using high-dose statins to prevent recurrence of thrombotic stroke.

Side Effects

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A very small number of people taking atorvastatin may have mild memory problems or confusion. If these rare effects occur, talk to your doctor. Rarely, statins may cause or worsen diabetes. Talk to your doctor about the benefits and risks.

This drug may rarely cause muscle problems (which can rarely lead to very serious conditions called rhabdomyolysis and autoimmune myopathy). Tell your doctor right away if you develop any of these symptoms during treatment and if these symptoms persist after your doctor stops this drug: muscle pain/tenderness/weakness (especially with fever or unusual tiredness), signs of kidney problems (such as change in the amount of urine).

This medication may rarely cause liver problems. If you notice any of the following rare but serious side effects, tell your doctor right away: yellowing eyes/skin, dark urine, severe stomach/abdominal pain, persistent nausea/vomiting.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above,
contact your doctor or pharmacist.

Reference

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