AMIODARONE
NOTES
CLASS 3 ANTIARRHYTHMIC
Prolongs action potential duration and QT interval by blocking K
•Causes peripheral vasodilatation
Pharmacokinetics
•Bioavailability 35-65%
•Hepatic Metabolism
•Elimination
•50% of drug in 3-10 days- rapid component
•Slower component- several weeks
•Effects maintained for 1-3 months following discontinuation
•Drugs that inhibit the enzyme increase its concentrations egH2 blocker Cimetidine
•Drugs that induce the enzyme egRifampicin, decrease concentrations
TOXICITY
-Arrhythmias: Bradycardia and Heart Block
-Accumulates in
•Heart , Lung , Liver and Skin- (photodermatitis- gray-blue skin discolourationin sun-exposed areas)
•Dose related Pulmonary Toxicity- Fatal Pulmonary Fibrosis in 1% of patients
•Hypersensitivity Hepatitis may develop with abnormal LFTs
•Thyroid Function: blocks peripheral conversion of thyroxine(T4 to T3. Can result in Hyper/Hypothyroid
Prolongs action potential duration and QT interval by blocking K
•Causes peripheral vasodilatation
Pharmacokinetics
•Bioavailability 35-65%
•Hepatic Metabolism
•Elimination
•50% of drug in 3-10 days- rapid component
•Slower component- several weeks
•Effects maintained for 1-3 months following discontinuation
•Drugs that inhibit the enzyme increase its concentrations egH2 blocker Cimetidine
•Drugs that induce the enzyme egRifampicin, decrease concentrations
TOXICITY
-Arrhythmias: Bradycardia and Heart Block
-Accumulates in
•Heart , Lung , Liver and Skin- (photodermatitis- gray-blue skin discolourationin sun-exposed areas)
•Dose related Pulmonary Toxicity- Fatal Pulmonary Fibrosis in 1% of patients
•Hypersensitivity Hepatitis may develop with abnormal LFTs
•Thyroid Function: blocks peripheral conversion of thyroxine(T4 to T3. Can result in Hyper/Hypothyroid