Term
What 2 compartments does digoxin distribute into?
What is it a substrate for? |
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Definition
- Plasma - small
- Tissue (heart) - large
- p-gp substrate, renally eliminated --> interaction w/ Amiodarone, macrolides, itra/ketoconazole, verapamil, tetracycline |
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Term
| What drugs inhibit P-gp and how does this affect Digoxin? |
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Definition
Amiodarone, macrolides, itra/ketoconazole, verapamil, tetracycline.
P-gP is an efflux pump, keeps this out of body. Inhibited, more stays in |
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Term
| What can contribute to digoxin toxicity? |
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Definition
Electrolyte imbalances - Low K/Mg, high Ca.
Elderly, decr renal function, hypothyroidism, renal clearance drugs |
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Term
| What is digoxin used for? |
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Definition
- Rate control in Afib - 0.25 mg IV q2h up to 1.5 mg, then 0.125 - 0.375 QD
- HF: 0.125 - 0.25 QD
- Only orally available 70-80% --> IV dose/0.8 = oral dose |
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Term
How is digoxin monitored?
How is toxicity cured? |
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Definition
7-14 days after maintenance initiated/changed, before the next dose and avoid distribution phase
- CHF goal - 0.5-1 mcg/L
- Afib goal - 0.5 - 2 mcg/L
- Monitor adverse effects: GI distress, visual halos, loss of appetite, confustion
- Digibind displaces out of tissue compartment into plasma, levels not accurate. |
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Term
| What are significant Amiodarone PK? |
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Definition
- Peaks/half life in months, analog to thyroid hormone
- Substrate for many CYP enzymes/p-gp, and inhibits many enzymes -- many drug interactions |
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Term
What are major amiodarone AEs?
How is amiodarone monitored? |
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Definition
Hypotension
Pulmonary fibrosis - PFT & CXray yearly
Corneal microdeposits - eye exam
Hepatic dysfunction - LFTs q6months
Hypothyroidism - T4 test q6months
Blue skin!!
- ECG at baseline and every followup |
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Term
| What major interactions does Amiodarone have? |
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Definition
- Warfarin - monitor INR very closely, will need to decr dose of warfarin
- Digoxin - discontinue or halve dose, monitor for toxicity |
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Term
| What is multaq/Dronedarone used for? |
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Definition
Reduce risk of hospitalizations by maintaining sinus rhythm
Cannot use in permanent Afib, ADHF, AV block, SSS, 3A4 inhibitors, QTc prolongers, hepatic impairment, pregnancy, QTc > 500, bradycardic
KILLS PEOPLE WITH HF |
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Term
What adverse effects should be monitored in dronedarone?
What are differences between Amiodarone and Dronedarone? |
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Definition
- Increased QTc
- Liver impairment
- SCr increase
Amiodarone converts to sinus rhythm while Dronedarone maintains. Dronedarone has a much shorter half life. Amiodarone can be used in HF |
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Term
| What is important to know about Quinidine? |
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Definition
| Substrate and inhibitor of 3A4, Causes torsades and RBC problems. Monitor LFTs, ECG, CBC |
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Term
| What is important to know about Procainamide? |
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Definition
| Can develop a lupus-like rash, has an active metabolite that lasts longer. 2D6 substrate. Can prolong QT, monitor ECG, SCr, LFTs |
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Term
| What is important to know about Disopyramide? |
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Definition
| Causes anticholinergic effects and QT prolongation - monitor ECG, SCr, LFTs, side effects |
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Term
| What is important to know about Lidocaine? |
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Definition
| Used in emergencies, short acting. Interacts w/ smoking. Causes dizziness, monitor ECG and BP |
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Term
| What is important to know about Mexiletine? |
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Definition
Can't use if a smoker, AV block, shock.
Causes GI upset, hypotension. Monitor ECG, BP, side effects |
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Term
| What is important to know about Flecainide? |
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Definition
| Causes QT prolongation, visual disurbances, GI upset. Monitor ECG, LFTs, counsel on side effects |
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Term
| What is important to know about Propafenone? |
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Definition
Has 2 active metabolites and several CYP interactions. Can CAUSE AV block, QT prolong, bradycardia, taste changes.
Monitor LFTS, ECG, BP, signs of HF |
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Term
| What is important to know about Dofetilide/Tikosyn? |
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Definition
Can CAUSE torsades, do not use in QT >440
Renally excreted
Must be started inpatient - baseline QT, post dose for first 5 doses, and q3months once stable. Monitor electrolytes and urine output, Scr, BP/HR |
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Term
| What is important to know about Sotalol? |
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Definition
| Prolongs QT, has BB properties (bradycardia, asthma, fatigue). Mostly used inpatient, not well tolerated. Monitor ECG (Continuous w/ IV), SCr, electrolytes, do not discontinue abruptly |
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Term
| What is the difference between Afib and atrial flutter? |
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Definition
- Afib - supraventricular, Irregularly irregular pulse. Extremely rapid pulse w/ abnormal activation
- flutter - Rapid beat at a regular rate |
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Term
| What are the different kinds of Afib? |
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Definition
- Paroxysmal - self-terminating, last 7 or less days
- Persistant - recurring, last longer than 7 days
- Permanent - Cardioversion failed |
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Term
What are S/S someone is in Afib?
How is it firmly diagnosed? |
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Definition
- Worsening symptoms of HF
- Syncope
- Cardioembolic stroke
- Diagnosed with S/S, ECG, labs |
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Term
| What are the 3 goals of Afib treatment? |
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Definition
- Acute treatment
- If persistant/permanent - long term Tx
- Thromboembolism prevention |
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Term
| What should be done if a patient is hemodynamically unstable? |
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Definition
| Symptoms of cardiogenic shock - use direct current cardioversion (DCC) immediately |
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Term
| How should acute rate control be managed in patients? |
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Definition
- no HF: IV metoprolol 2.5-5 q5 min x 3 doses, then orally OR NON-DHP CCBs
- HF: Metoprolol --> Digoxin --> Amiodarone all IV
- Paroxysmal - need no further Tx unless symptomatic |
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Term
| When should Rhythm control be used for long term management? |
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Definition
Usually use rate control - AFFIRM says just as good
Use in first time patients in a young age, or patients with repeat symptoms/contraindication to BB |
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Term
| What drugs are used for rate control? |
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Definition
- No HF - Metoprolol or Propranolol --> non-DHP CCBs --> digoxin
- HF - Metoprolol/Coreg/Zebeta --> Digoxin. NO CCBS
Titrate dose to achieve goal HR of <110 |
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Term
| When can a patient undergo cardioversions/why is it an issue? |
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Definition
Cardioversion increases the risk for stroke
- AF <48h - cardioversion w/ heparin or LMWH
- AF w/ >48h or unknown duration - warfarin for 3 weeks (therepeutic) prior and 4 weeks after
- Can do a TEE to check for a clot. |
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Term
| What drugs can be used within 7 days (AF < 48h or check with TEE)? |
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Definition
- Dofetilide - OK in HF, inpatient only, no BB needed
- Flecainide - Not used in HF, in/out, USE BB
- Ibutilide - not used in HF, inpatient only, no BB needed
- Propafenone - not used in HF, In/Out, NEED BB
- Amiodarone - OK in HF, in/out, no BB needed |
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Term
| Which drugs can be used for cardioversion after 7 days have elapsed? |
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Definition
None of these drugs require beta blockers
- Dofetilide - used in HF, inpatient only
- Ibutilide - no HF, inpatient only
- Amiodarone - Used in HF, in/out |
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Term
| How does pill in pocket cardioversion work? |
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Definition
patients with symptoms take one dose of Flecainide or Propafenone, must also be on BBs
- no HF, QT prolong, AV block |
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Term
| What drugs are the first line for maintenance of sinus rhythm? |
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Definition
- No structural HD - Dronedarone --> Flecainide/Propafenone/Sotalol
- HTN - no LVH (Dronedarone), LVH (Amiodarone)
- CAD - Dofetilide
- HF - Amiodarone --> Dofetilide
Ablation is a last resort |
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Term
| How are patients managed for anti-thrombotic therapy? |
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Definition
- Low risk - ASA 325 mg po QD
- Moderate risk - Warfarin INR 2-3 or ASA 325 po QD
- High risk - Warfarin INR 2-3 or Pradaxa or Xarelto |
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Term
What are risk factors for thromboembolism?
When is someone considered high risk? |
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Definition
- Age >/ 75
- HTN
- HF AND EF - DM2
- High risk if previous stroke/TIA, mitral stenosis, valve, or 2+ moderate risk factors |
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Term
| How is someone's CHADS2 score measured? |
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Definition
| - 1 point for HTN, DM2, HF, Age > 75, 2 points for prior stroke |
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Term
| What is done if a high risk patient is unable to take warfarin? |
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Definition
| ASA 325 mg + Plavix 75 mg |
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Term
| How is Pradaxa used for Afib? |
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Definition
- DTI, 150mg BID, 75mgBID if CrCL < 30. Can cause bleeding and dyspepsia, is a P-gp substrate (amiodarone, itra/ketoconazole, dronedarone, Macrolides)
- No antidote for bleeding, D/C for surgery (usually 1-2 days) |
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Term
| How is Xarelto used for Afib? |
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Definition
- 20 mg with evening meal if CrCl > 50, 15 if under 50. MUST BE TAKEN WITH FOOD.
- Also P-gp substrate, watch Ritonavir.
- Stop warfarin, start when INR <3
- Also no antidote, specific warning w/ epidurals |
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Term
| What are types of ventricular arrhythmias? |
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Definition
- Vtach - obvious, regular rhythm w/ a high rate. More than 30 sec needs immediate interventions. Give Amiodarone, an ICD, or DCC if necessary
- V-fib - no pulse, treat w/ DCC --> Epi --> amiodarone, lidocaine, procainamide
- Premature ventricular contraction - happens to anyone, 6+ a minute = problem - amiodarone and dofetilide
- Torsade - prolonged QTc |
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Term
| What drugs can induce TdP? |
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Definition
- usually a combo of several drugs associated w/ potassium.
- prolonged QTc at baseline, electrolye disturbances, female
- DOFETILIDE, amiodarone, Levaquin, Zofran, Paxil, Ranexa, Atypical antipsychotics
- Type 1a (quinidine), type 3, and K-channel blockers
- If QT > 450 at base, don't give drug. If >560 on drug, stop drugs |
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