Cardiotonic agents

Question 1

Cardiac Glycosides

Answer 1

Digoxin (Lanoxin)

Question 2

Actions of digoxin

Answer 2

Increases intracellular calcium, allows more calcium to enter the myocardial cell during depolarization; positive inotropic effect, increased renal perfusion with a diuretic effect and decrease in renin release, and slowed conduction through the AV node

Question 3

Indications for digoxin

Answer 3

Treatment of HF, atrial fibrillation

Question 4

C & C for digoxin

Answer 4

Contra- allergy, Vtach or Vfib, Heart block or sick sinus syndrome, Idiopathic hypertropic subaortic stenosis, Acute MI, renal insufficiency and electrolyte abnormalities.

Caution- pregnancy and lactation, pediatric and geriatric patients.

Question 5

Pharmo for digoxin

Answer 5

Route- oral, IV
Onset- 30-120 min, 5-30 min
Peak- 2-6h, 1-5 h
Dx- 6-8 d, 4-5 d
T 1/2- 5-30min
Rapidly absorbed and widely distributed throughout the body
Primarily excreted unchanged in the urine

Question 6

Adverse effects for digoxin

Answer 6

Headache, weakness, drowsiness, and vision changes
GI upset and anorexia
Arrhythmia development

Question 7

D2D for digoxin

Answer 7

Verapamil, amiodarone, quinidine, quinine, erythromycin, tetracycline, or cyclosporine.
Potassium losing diuretics
Cholestyramine, charcoal, colestipol, bleomycin, cyclophosphamide, or methotrexate

Question 8

Special info for digoxin

Answer 8

Digoxin (lanoxin) can be given in a loading dose but you need to 0.1-0.25 mg/mL IV dosed is a normal dose. IF you question an order you need to look it up and then call the MD again.

HR less than 60 you need to hold this.

Question 9

Phosphodiesterase inhibitors

Answer 9

Inamrinone (Inocor): Approved only for use in patients with HF that has not responded to digoxin, diuretics, or vasodilators

Milrinone (Primacor): Short-term management of HF in patients who are receiving digoxin and diuretics

Question 10

Actions for Inamrinone (Inocor)

Answer 10

Blocks the enzyme phosphodiesterase, leads to an increase in myocardial cell cyclic adenosine monophosphate (cAMP), which increases calcium levels in the cell, causing a stronger contraction and prolonged response to sympathetic stimulation; directly relaxes vascular smooth muscle

Question 11

Indications for Inamrinone

Answer 11

Short-term treatment of HF in patients unresponsive to digitalis, diuretics, or vasodilators

Question 12

Pharmo for Inamrinone

Answer 12

Route- IV
Onset- Immediate
Peak- 10min
Dx- 2hr
T 1/2- 3.6 to 5.8 hrs
Widely distributed after injection
Metabolized in the liver and excreted in the urine

Question 13

C & C for Inamrinone

Answer 13

Contra- allergy, sever aortic or pulmonic disease, MI, fluid volume deficit, and ventricular arrhythmias

Caution- pregnancy or lactation, elderly.

Question 14

Adverse effects for Inamrinone

Answer 14

Arrhythmias, Hypotension, Nausea, Vomiting
Thrombocytopenia, Pericarditis
Pleuritis,Fever, Chest Pain
Burning at Injection Site

You have lots of problems with phosphodiesterase inhibitors thus it is not the primary drug of choice and you need to do a CBC to monitor for thrombocytopenia.

Question 15

D2 D interaction for Inamrione

Answer 15

Furosemide