Final answer:
Amiodarone is a medication used to treat irregular heart rhythms. Its oral bioavailability can vary between individuals, and doses may need to be adjusted in patients with liver or kidney dysfunction. Missing one or two doses is unlikely to cause severe consequences, but it is important to take the medication as prescribed. Amiodarone is metabolized in the liver via demethylation and it can decrease the refractory period of cardiac myocytes.
Step-by-step explanation:
Amiodarone is a medication used to treat irregular heart rhythms, also known as cardiac dysrhythmias. It is important to understand the pharmacokinetics of amiodarone in order to use it effectively and safely.
Regarding the statements in the question:
- Oral bioavailability is reliable: Amiodarone has variable oral bioavailability, meaning that the amount of the drug that enters the systemic circulation after oral administration can vary greatly between individuals.
- Doses must be reduced in renal and hepatic failure: Amiodarone is primarily metabolized by the liver and excreted in the bile. In patients with impaired liver or kidney function, the dose of amiodarone may need to be reduced to avoid toxicity.
- Omission of 1 or 2 doses can lead to severe consequences: Amiodarone has a long half-life, which means that missing one or two doses is unlikely to have immediate severe consequences. However, it is important to take the medication as prescribed to maintain stable blood levels and prevent sudden changes in heart rhythm.
- Metabolism is via demethylation: Amiodarone undergoes extensive metabolism in the liver, including demethylation, as well as other metabolic pathways.
- Decreases refractory period: Amiodarone prolongs the refractory period of cardiac myocytes, which can help prevent abnormal electrical activity in the heart.