B / 4 : Positive inotropic drugs Flashcards
1
Q
Compensatory mechanisms for heart failure
A
- Increased SYM tone
- Increasing contractility
- Ventricular hypertrophy
2
Q
What do positive inotropic drugs do?
A
Improve the contractile force of the heart but also exhaust it
3
Q
Which drugs are used for chronic treatment of HF?
A
cardiac glycosides (digoxin, digitoxin)
4
Q
Cardiac glycosides
- MOA
- Effect
- Indication
- Contraindication
- SE
- ROA
A
- Na+/K+ ATPase inhibitor
- Increased IC Ca2+ : better contractile force + increased parasympathetic tone in heart causes hyperpolarization and negative dromotropic effect
- For CHF, atrial fibrillation
- AV block, v-fib, AMI
- Bradycardia, AV block, hyperkalemia
- Oral, IV
5
Q
Where are digoxin and digitoxin metabolized?
A
Digoxin is metabolized in the kidney while digitoxin is metabolized in the liver
6
Q
What is the treatment for a digitoxin intoxication?
A
- Digitalis binding antibody
- Treatment of electrolyte disturbances
- Anti-arrythmic drugs
7
Q
Symptoms of digitoxin intoxication? (4)
A
- Extreme bradycardia, AV block
- ST depression, T inversion
- Color vision disturbances
- Headaches, hallucinations
8
Q
Dobutamine
- MOA
- Effect
- Indication
- SE
- ROA
A
- B1 agonist
- Increased CO, SV
- For acute HF, CHF, cardiogenic shock
- Tolerance
- Parenteral
9
Q
What is the maintenance dose of digoxin?
A
1x0.25mg
10
Q
Drugs used for acute treatment of HF
A
- Catecholamines (dobutamine)
- PDE-3 inhibitors (milrinone, levosimendan)
11
Q
Milrinone
- MOA
- Effect
- Indication
- SE
- ROA
A
- PDE-3 inhibitor
- Increased cAMP (usually broken down by PDE) causes increased inotropy
- Acute heart failure
- Increased morbidity and mortality
- IV ONLY
12
Q
Levosimendan
- MOA
- Effect
- Indication
- SE
- ROA
A
- Ca2+ sensitizer for troponin and PDE3 inhibitor
- Positive inotropic effect and vasodilation by PDE inhibition
- For acute decompensated HF, shock
- Headaches, hypotension, arrythmia
- IV
