Atorvastatin

BRAND NAMES:

• Atorvaliq: It is the combination of Atorvastatin calcium, which is available in the market as Atorvastatin calcium oral suspension (20 mg/5 ml). It reduces the risk of myocardial infarction, stroke, revascularization procedures and also reduces the multiple risk of coronary disease. It is bioequivalent to atorvastatin tablet dose.

• Caduet: Caduet is a combination of amlodipine besylate (5 or 10mg) and atorvastatin calcium (10, 20, 40 or 80mg) available in the form of film-coated tablets used in the treatment of hypertension to lower blood pressure.

• Lipitor: It is an atorvastatin calcium tablet (10, 20, 40 or 80mg) intended to minimize the risk of heart attacks and strokes in adults by decreasing bad cholesterol in the bloodstream. It gradually reduces the creation of cholesterol, which can accumulate on the artery walls and obstruct blood flow to the heart, brain, and other regions of the body.

• Lypqozet: Lypqozet is a combinational drug containing atorvastatin calcium trihydrate (10.34mg) and ezetimibe (10mg) in the form of tablets, dosage ranging from 10/10 mg/day to 10/80 mg/day. It is mainly administered to patients who require a larger reduction of bad cholesterol LDL-C.

MECHANISM OF ACTION:

Atorvastatin suppresses the enzyme 3-hydroxy-3-methylglutaryl-co-enzyme A reductase. Statins lower cholesterol synthesis in the liver by blocking the conversion of HMG-CoA to mevalonate. Atorvastatin increases the amount of LDL receptors on the surface of hepatic cells. In patients with homozygous or heterozygous familial hypercholesterolaemia, atorvastatin has been shown to lower total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, very-low-density lipoprotein, and triglyceride levels while increasing high-density lipoprotein cholesterol. In patients with dysbetalipoproteinemia, atorvastatin has been found to lower intermediate-density lipoprotein levels.

PHARMACOKINETICS:

Absorption: Atorvastatin is readily absorbed after oral administration, reaching peak plasma levels in 1 to 2 hours. Because of significant first-pass metabolism, the bioavailability is just 14%.

Distribution: Atorvastatin is highly plasma protein bound (over 98%) and has a volume of distribution of around 380 liters.

Metabolism: CYP3A4 metabolizes atorvastatin into active ortho and para-hydroxylated molecules.

Excretion: The bile eliminates atorvastatin and its metabolites. Atorvastatin does not appear to recirculate via the liver. The half-life of atorvastatin is around 14 hours, while that of its active metabolites is roughly 20-30 hours.

PHARMACODYNAMICS:

Atorvastatin's primary site of action is the liver, which is responsible for both cholesterol synthesis and LDL elimination. The degree of LDL-C decrease is determined by atorvastatin dosage rather than systemic drug concentration.

DOSAGE AND ADMINISTRATION:

Atorvastatin calcium tablets are available in 10, 20, 40, and 80 mg strengths. The dosage should be determined by the physician, taking into consideration the patient's age.

Atorvastatin is available as a calcium tablet. This medication can be used with or without food and should be taken simultaneously each day. Statins are frequently suggested for use before bedtime because endogenous cholesterol synthesis is cyclical, with peak levels occurring during fasting and at night. However, atorvastatin's longer half-life, as opposed to other statins' shorter half-lives, offers greater dosing flexibility.

CONTRAINDICATIONS:

• People allergic to any substances in atorvastatin should not use it.

• Although atorvastatin should not be used by anyone with active liver disease, lipid-lowering medications are often more beneficial than harmful in the treatment of chronic liver disorders such as nonalcoholic fatty liver disease and hepatitis.

• All female patients of reproductive age should be informed about the risks to their baby if they become pregnant while taking atorvastatin.

• Pregnant women should avoid atorvastatin. Because of the increased risk during the first trimester, current guidelines recommend discontinuing statin therapy at least three months before getting pregnant.

• Female patients who are nursing should not use atorvastatin; if the woman becomes pregnant, she should discontinue the medicine immediately.

DRUG INTERACTIONS:

Combining atorvastatin with strong CYP3A4 inhibitors can lead to higher plasma concentrations and worsen side effects, such as myopathy. OATP1B1 inhibitors can improve atorvastatin bioavailability. CYP3A4 inducers may cause decreased atorvastatin plasma concentrations.

When starting atorvastatin, patients taking digoxin should be watched as their plasma digoxin levels may increase. Atorvastatin may also increase norethindrone and oestradiol levels.

• Rifampin should be used alongside LIPITOR. Fibrate products and lipid-modifying doses of niacin increase the risk of skeletal muscle damage. It should be used to prescribe LIPITOR.

FOOD INTERACTIONS:

The presence of one or more CYP3A4 inhibitors can cause an increase in atorvastatin plasma concentrations.

SIDE   EFFECTS:

Common side effects of atorvastatin include

• Indigestion

• Diarrhea

• Nausea

• Inflammation in the nasal passage

• Insomnia, joint pains

• Urinary  infection

• Pain in the extremities

 OVERDOSAGE:

There is no specific treatment for a LIPITOR overdose. In the event of an overdose, patients should be treated symptomatically, with supportive measures implemented as needed. Due to considerable drug binding to plasma proteins, hemolysis is unlikely to appreciably improve LIPITOR clearance.

TOXICITY:

There are no antidotes for atorvastatin overdose. Patients should be evaluated for adverse events and offered supportive care.

STORAGE:

Store at room temperature between 68 ̊F (20̊C) and 77̊ F (25̊C).