-
What is the clearance for Dofetilide(III)?
80% renal; 20% CYP 3A4
-
What is the clearance for Ibutilide(III)?
90% hepatic; 10% renal
-
What is the clearance for Sotalol (III)?
80-90% renal
-
What is the clearance for Dronedarone (III)?
100% hepatic CYP 3A4
-
What is the t1/2 for amiodarone (III)?
53 days
-
What is the t1/2 for Dofetilide(III)?
10 hrs
-
What is the t1/2 for Ibutilide(III)?
6 hrs
-
What is the t1/2 for Sotalol (III)?
8-18 hrs
-
What is the t1/2 for Dronedarone (III)?
13-19 hrs
-
Which is the most cardiotoxic drug class of antiarrhythmics?
- Class 1A
- Worsen HF and can cause torsades
-
Which antiarrhythmics are “cardiac neutral”, causing few cardiac side effects?
Lidocaine and Mexiletine
-
Why is Mexiletine a last resort medication?
- High CNS side effects
- Not well tolerated
-
What are the cardiac side effects of Flecanide, and Propafenone (Class 1C)?
- Worsen HF
- Cause HB
- Proarrhythmic (low incidence of torsade) but cause monomorphic ventricular tachycardia
-
Of the class III drugs, which ones are more proarrhythmic?
Dofetilide ,ibutilide and sotolol
-
Of the class III drugs, which ones are less proarrhythmic?
- Amiodarone and Sotolol
- (Be careful when using them with other QT prolonging drugs)
-
Which Class III drugs are Cardiac neutral?
Amiodarone and Dofetilide
-
Which Class III drugs are safe to use in patients having HF or underlying structural heart disease?
Amiodarone and Dofetilide
-
Which Class III drug is absolutely CI in patients having HF or underlying structural heart disease?
- Sotolol
- (don’t use flecanide or propanfenone either, though)
-
Why should you not use verapamil or diltilazem in patients that have SHF?
Can lower BP, reduce HR and cause heart block
-
What is the most used/valued class?
III
-
Is it normal to see a QT interval >500 for Amiodarone?
No, but still very very low torsades profile
-
Which Class III antiarrhythmics have a profound reduction in HR?
- Amiodarone and sotolol
- Because of BB activity
-
Why do Amiodarone and Sotolol have heart blocking capabilities?
BB blockers
-
What does it mean to be cardiac neural?
- Does not worsen mortality
- Safer in HF or structural Heart changes
-
What are the side effects of Quinidine?
GI (diarrhea), N/V, cinchonism (tinnitus, headache, nausea, blurred vision, psychosis, delirium), hepatotoxicity, drug fever, thrombocytopenia, hemolytic anemia
-
What are the side effects of Procainamide?
Neutropenia, drug-induced lupus, (up to 50% DC rate), GI
-
What are the side effects of Disopyramide?
Anticholinergic (urinary retention, dry mouth, blurred vision, constipation) - 70% of patients, hypoglycemia
-
What are the side effects of Lidocaine?
CNS
-
What are the side effects of Mexiletine?
CNS, GI, hepatotoxicity
-
What are the side effects of Flecainide, Propafenone?
CNS (dizziness, visual disturbances, headache), GI
-
What are the side effects of Dofetilide, Ibutilide?
CNS, GI
-
What are the side effects of Sotalol?
Beta-blocking effects
-
What are the side effects of Dronedarone?
↑ Scr
-
What are the GI side effects of Amiodarone?
N/V (most common), constipation, weight gain, weight loss (anorexia)
-
What are the CNS side effects of Amiodarone?
headache, ataxia, insomnia or other sleep disturbances, malaise, fatigue, dizziness, paresthesia, abnormal smell, tremor, peripheral neuropathy, proximal myopathy
-
What are the Pulmonary side effects of Amiodarone?
- Pulmonary interstitial pneumonitis, hypersensitivity pneumonitis (both short lived)
- Most catastrophic: Pulmonary Fibrosis (irreversible)
-
What are the Dermatologic side effects of Amiodarone?
Photosensitivity, blue-gray discoloration (reversible when D/C’d), hair loss, rash
-
What do you do if an amiodarone patient presents with Pulmonary fibrosis?
Stop Amiodarone
-
How does Pulmonary fibrosis present?
Fatigue, or flulike illness, blue-gray
-
What is the most common oral Amiodarone side effect?
N/V
-
How long will amiodarone SE last?
-
Why does Amiodarone cause Hyper or more commonly, Hypo thyroid?
- 35% Iodine by Volume
- Taken up into thyroid
-
If a patient is on Levothyroxine and is receiving Amiodarone, what most likely should be done?
Increase Levothyroxine ( high chance of Hypothyroidism)
-
What are the Hematopoetic side effects of Amiodarone?
Thrombocytopenia, spontaneous ecchymosis, coagulation abnormalities
-
What are the Endocrine side effects of Amiodarone?
Hyperthyroidism, hypothyroidism
-
What are the Opthalamologic side effects of Amiodarone?
Hyperthyroidism, hypothyroidism
-
What are the Hepatic side effects of Amiodarone?
Elevations in serum transaminases, hepatotoxicity
-
What are the baseline tests that should be run when placing a patient on Amiodarone?
PFT, CXR, Thyroid panel, Liver panel, ECG, Eye exam, CBC, BMP, Neurologic, Dermatologic
-
What are the 3 month tests that should be run when placing a patient on Amiodarone?
ECG, CBC, BMP, Neurologic, Dermatologic
-
What are the 6 month tests that should be run when placing a patient on Amiodarone?
Thyroid panel, Liver panel, ECG, CBC, BMP, Neurologic, Dermatologic
-
What are the 12 month tests that should be run when placing a patient on Amiodarone?
Thyroid panel, Liver panel, ECG, Eye exam, CBC, BMP, Neurologic, Dermatologic
-
What test should be run on an amiodarone patient if they are symptomatic?
- All:
- PFT, CXR, Thyroid panel, Liver panel, ECG, Eye exam, CBC, BMP, Neurologic, Dermatologic
-
Why does Amiodarone have lots of drug interactions?
CYP3A4 inhibitor
-
What are the CYP3A4 statins?
lovastatin, simvastatin, and atorvastatin
-
Which statin is most concerning when used with Amiodarone, why and what should be done?
- Simvastatin, because it has a high risk of myalgias
- No more than 20 mg dose with Amiodarone or switch to Crestor
-
What drugs does Amioarone mainly interact with?
- Warfarin
- Digoxin
- Penytoin and Phenobarbitol
- Cyclosporine and Tacrolimus
- Statins
-
What are the consequences of Warfain and Amiodarone combo and how should you treat this?
- Warfarin metabolism inhibited
- Increased: PT, INR and bleeding risk
- Treatment: Reduce warfarin dose by 25-50%; titrate to desired INR
-
What are the consequences of Digoxin and Amiodarone combo?
- Digoxin concentration increased by unknown mechanism
- effect including sinus arrest, AV block, GI and neurological toxicity
- Treatment: Reduce digoxin by 25-50%; titrate to therapeutic digoxin level
-
What are the consequences of Cyclosporine or Tacrolimus and Amiodarone combo?
- Cyclosporine/tacrolimus levels increase due to 50% reduction in clearance
- Treatment: Monitor plasma concentrations with dosage adjustment
-
What are the consequences of Phenytoin or Phenobarbitol and Amiodarone combo?
- Increased concentration of phenytoin and phenobarbital
- Increased neurologic toxicity
- Treatment: Monitor plasma concentrations with dosage adjustment
-
What are the consequences of Statin and Amiodarone combo?
- Statin metabolism inhibited, Increased risk of myopathy/myalgia
- Treatment: Avoid doses of statins when on amiodarone (no more than lovastatin 40 mg, simvastatin 20 mg, and atorvastatin 10 mg)
|
|