Amiodarone

Amiodarone is a medication that is widely used to treat cardiovascular disorders such as arrhythmias. Its main active ingredient, amiodarone, has multifaceted effects on the cardiovascular system.

Amiodarone belongs to the class of antiarrhythmic agents and is commonly used to control heart rhythm for various types of arrhythmias, including atrial fibrillation, atrial fibrillation, atrial fibrillation, extrasystole, and other heart rhythm disorders.

The action of amiodarone is based on its ability to block various ion channels in heart cells, which leads to improved electrical stability of the heart and reduces the possibility of arrhythmias.

It is important to note that amiodarone is a strong medication and can have significant side effects, so its use should be carried out under the strict supervision of a doctor and in compliance with the recommended dosages.

Indications Amiodarone

1. Atrial Fibrillation (Atrial Fibrillation): Amiodarone is often used to control heart rhythm in atrial fibrillation, especially when other antiarrhythmic agents have proven ineffective or insufficient.
2. Atrial fibrillation (Atrial fibrillation tachycardia): Amiodarone may also be used to treat atrial fibrillation, especially when it recurs.
3. Ventricular tachycardia: In some cases, amiodarone may be used to treat ventricular tachycardia, especially when it is persistent or life-threatening.
4. Prevention of arrhythmia recurrences: Amiodarone may be prescribed to prevent recurrences of cardiac arrhythmias in patients at high risk of developing them.
5. Postinfarction therapy: In some cases, amiodarone may be used to prevent the development of cardiac arrhythmias in patients after myocardial infarction.
6. Other cardiovascular disorders: In rare cases, amiodarone may be used to treat other cardiovascular disorders, such as tachycardias unrelated to arrhythmias, or to manage certain types of cardiac dysfunction.

Release form

1. Pills:

   • The most common form of release. Amiodarone tablets usually contain 200 mg of the active substance. Tablets are taken orally and may be coated to improve absorption and reduce gastrointestinal side effects.

2. Solution for injection:

   • Amiodarone is also available as an intravenous solution, which is used in acute settings where a rapid effect on heart rhythm is required. The solution for injection is often used in hospital settings, especially for acute conditions such as ventricular tachyarrhythmias.

Pharmacodynamics

1. Blocking ion channels: Amiodarone blocks several different types of ion channels in the heart, including potassium, sodium, and calcium channels. This leads to changes in the duration of the cardiomyocyte action potential and delayed repolarization, which may help prevent the occurrence or reduce the frequency of cardiac arrhythmias.
2. Antiarrhythmic action: Amiodarone has class III antiarrhythmic action according to the Wong-Baker classification, which means its ability to prevent the break in repolarization of cardiomyocytes and thus prevent the occurrence of early and late subsequent depolarizations.
3. Adrenoreceptor antagonism: Amiodarone also has adrenoreceptor blocking properties, which may reduce the sensitivity of cardiac tissue to catecholamines such as adrenaline and norepinephrine and thereby reduce the risk of tachycardia or other arrhythmias caused by sympathetic stimulation.
4. Vasodilating action: Amiodarone may also causevasodilation and a decrease in peripheral resistance, which may be useful in the treatment of some forms of arrhythmias associated with increased peripheral resistance and hypertension.
5. Anti-inflammatory and antiviral effects: Some studies have shown that amiodarone may have anti-inflammatory and antiviral properties that may help treat some forms of arrhythmias associated with inflammatory or infectious processes in the heart.

Pharmacokinetics

1. Absorption: Amiodarone usually has high bioavailability when taken orally. It may be slowly and incompletely absorbed from the gastrointestinal tract.
2. Distribution: It is widely distributed in body tissues, including heart muscle, liver, lungs and adipose tissue. This may lead to prolonged half-removal and accumulation of amiodarone in the body.
3. Metabolism: Amiodarone undergoes significant metabolism in the liver, including formation of active and inactive metabolites. The main metabolites are deethylated amiodarone and n-desethylamiodarone.
4. Excretion: The excretion of amiodarone and its metabolites is mainly through bile and intestine, and to a lesser extent through the kidneys.
5. Half-removal: Half-removal of amiodarone from the body is long, usually ranging from 40 to 55 days. This is due to its prolonged accumulation in adipose tissue.

Dosing and administration

Ways of application:

1. Oral administration (tablets):

• Amiodarone tablets are usually taken with a meal or immediately after a meal to minimize stomach upset.
• Tablets should be swallowed whole without chewing to avoid irritation of the oral mucosa.

2. Intravenous administration (injections):

• Amiodarone injections are administered in medical facilities under close supervision because of the risk of serious side effects.
• The solution for injection is administered slowly, usually over 10 minutes or more, to prevent serious cardiovascular reactions.

Dosage:

For adults:

1. Oral administration:

• Initial dose (loading phase): Usually 800-1600 mg daily for 1-3 weeks until therapeutic blood levels are reached.
• Maintenance dose: After the loading phase, the dose is usually reduced to 200-400 mg per day. Your doctor can adapt the dose depending on your condition and response to treatment.

2. Intravenous administration:

• Initial dose: 5 mg per kg of patient body weight, administered slowly over 20-120 minutes.
• Maintenance infusion: 10-15 mg/h, maximum allowable dose - 1.2 g per day.

Special Instructions:

• Before starting treatment with amiodarone and during therapy, ECG should be performed regularly and liver, thyroid and lung functions should be monitored.
• Amiodarone can interact with many other drugs, which requires caution when prescribing it in combination with other drugs.
• Because of the risk of photosensitivity, patients are advised to use sunscreen and wear protective clothing to prevent sunburn in the light.

Use Amiodarone during pregnancy

The use of amiodarone during pregnancy may be associated with a risk for the development of side effects in both mother and fetus. Amiodarone may penetrate the placenta and affect the developing fetus. Therefore, its use should be performed only in cases of extreme necessity and under strict medical supervision.

Contraindications

1. Hypersensitivity: People with known hypersensitivity to amiodarone or any other components of the drug should avoid its use.
2. Bradycardia: Amiodarone may cause bradycardia and should therefore be used with caution in patients with sinus bradycardia or cardiac conduction abnormalities.
3. AV block: In patients with AV block, the use of amiodarone may result in increased conduction blockade.
4. Thyrotoxicosis: If thyrotoxicosis is present, the use of amiodarone may worsen the condition.
5. Liver insufficiency: The drug should be used with caution in patients with hepatic insufficiency, as it may cause an increase in the activity of hepatic enzymes.
6. Pregnancy and breastfeeding: Amiodarone use during pregnancy may be limited due to its toxic effect on the fetus. It is also not recommended to use during breastfeeding due to high concentration of the drug in breast milk.
7. Photosensitivity: Taking amiodarone may increase sensitivity to sunlight, which can lead to photosensitivity and photodermatitis.
8. Myasthenia gravis: Amiodarone use may increase muscle weakness in patients with myasthenia gravis.

Side effects Amiodarone

1. Increased sensitivity to sunlight (photosensitivity): Patients taking amiodarone may become more sensitive to ultraviolet light, which may result in sunburns or other skin reactions.
2. Hepatotoxicity: Amiodarone may cause liver damage, which is manifested by increased levels of liver enzymes in the blood and, in rare cases, the development of hepatitis.
3. Thyrotoxicosis: Amiodarone use may cause thyroid dysfunction, including hyperthyroidism or hypothyroidism.
4. Pulmonary complications: Includes pneumonitis, pulmonary fibrosis, and other pulmonary complications.
5. Ophthalmologic complications: Include corneal opacities (keratopathy) and optic neuropathies.
6. Neurological complications: Development of peripheral neuropathy, myasthenia gravis and other neurological complications is possible.
7. Skin reactions: May include rash, itching, skin redness, and other skin manifestations.
8. Other rare side effects: Include arrhythmias, hypotension, hypothyroidism, arterial embolism, and others.

Overdose

1. Cardiac arrhythmias: Amiodarone overdose may cause cardiac arrhythmias, including tachycardia, bradycardia, atrial fibrillation and other heart rhythm disturbances. This is due to its antiarrhythmic action and potential effects on cardiac conduction.
2. Prolonged QT interval: Amiodarone may cause prolongation of the QT interval on the ECG, which may increase the risk of severe arrhythmias such as ventricular flutter.
3. Toxic effect on the thyroid gland: Amiodarone may cause a toxic effect on thyroid function, resulting in hypo- or hyperthyroidism.
4. Liver and lung damage: Prolonged use or overdose of amiodarone may cause liver or lung damage, manifested as hepatitis or interstitial pneumonitis.
5. Other Side Effects: Otherside effects associated with the use of amiodarone such as retinal thickening syndrome, photodermatitis, neuropathies, etc. Are also possible.

Interactions with other drugs

1. Hypersensitivity: People with known hypersensitivity to amiodarone or any other components of the drug should avoid its use.
2. Bradycardia: Amiodarone may cause bradycardia and should therefore be used with caution in patients with sinus bradycardia or cardiac conduction abnormalities.
3. AV block: In patients with AV block, the use of amiodarone may result in increased conduction blockade.
4. Thyrotoxicosis: If thyrotoxicosis is present, the use of amiodarone may worsen the condition.
5. Liver insufficiency: The drug should be used with caution in patients with hepatic insufficiency, as it may cause an increase in the activity of hepatic enzymes.
6. Pregnancy and breastfeeding: Amiodarone use during pregnancy may be limited due to its toxic effect on the fetus. It is also not recommended to use during breastfeeding due to high concentration of the drug in breast milk.
7. Photosensitivity: Taking amiodarone may increase sensitivity to sunlight, which can lead to photosensitivity and photodermatitis.
8. Myasthenia gravis: Amiodarone use may increase muscle weakness in patients with myasthenia gravis.