Question

Client Profile

Mrs. Kidway is a 71-year-old Russian woman who lives at home with her daughter’s family. She only speaks Russian; her daughter speaks English and translates for her Mother. Mrs. Kidway has a history of Heart failure (HF, CHF); pneumonia; chronic obstructive pulmonary disease (COPD); gastroesophageal reflux disease (GERD). Her daily medications prior to admission include digoxin (Lanoxin) 0.125 mg once a day.

Case Study

Mrs. Kidway arrives in the emergency room with her daughter who explains, “She was fine this morning but then this afternoon she developed terrible abdominal pain and got short of breath.” Mrs. Kidway is lethargic. Her physical examination is unremarkable except for facial grimacing when palpating her abdomen. She is afebrile with a blood pressure of 105/50, pulse 60, and respiratory rate 18. Blood work on admission reveals a digoxin level of 3.8 ng/mL.

1. How does digoxin work in the body?

2. Why is Mrs. Kidway taking digoxin?

3. Given Mrs. Kidway’s digoxin level, briefly explain what electrolyte imbalance is of concern.

During a nursing assessment of Mrs. Kidway’s current medications, the nurse asks if Mrs. Kidway takes any over-the-counter medications or herbal remedies. Mrs. Kidway’s daughter says, “Is licorice considered an herbal remedy? My mother started taking licorice capsules about a month ago because we heard that licorice helps decrease heartburn.”

4. Does licorice interact with digoxin? If so, explain.

5. Discuss what the terms loading dose and steady state indicate.

6. What are the onset, peak, and duration times of digoxin when it is taken orally?

7. If Mrs. Kidway was having difficulty swallowing her digoxin capsule and her health care provider changed her prescription to the elixir form of digoxin, theoretically would she still receive 0.125 mg?

8. What is a medication’s “half-life”? What is the half-life of digoxin? Theoretically, if Mrs. Kidway took her digoxin at 8:00 a.m. on a Monday, when will 75% of the digoxin be cleared from her body according to the half-life? Since the half-life of digoxin is prolonged in the elderly, use the high end of the range of digoxin’s half-life.

9. What is the normal therapeutic range of serum digoxin for a client taking this medication?

10. What symptoms may be noted when digoxin levels are at toxic levels?

11. At what serum digoxin range do cardiac dysrhythmias appear and what is the critical value for adults?

Mrs. Kidway’s heart rate drops to 50 beats per minute. Her potassium is 2.1 mEq/L. She has the following orders:

1. Four vials of intravenous digoxin immune fab (Digibind), reconstituted with sterile water
2. Potassium chloride (KCl) 40 meq in 200 mL NS to run IV to run over 4 hours
3. Atropine sulfate (Atropine) 0.5 mg IV
4. Start a large bore IV.
5. Admitt to the intensive care unit for cardiac monitoring.

12. Prioritize the orders and provide your rationale.

13. Discuss how her digoxin toxicity will be treated.

14. What are the two highest priority nursing diagnoses appropriate for Mrs. Kidway’s plan of care?

Answer 1

1. How does digoxin work in the body?

Digoxin is a cardiac glycoside.That means these are the chemical compounds that causes the increase in the force of the cardiac contraction and reduce the heart rate by acting on the sodium pottasium ATPase pump.This is the drug usualy used to treat heart failure.By using this digoxin the heart will be able to pump blood more efficiently to differentparts of the body.This medicine inhibits the ATPase enzyme and regulate the movement of the electrolytes such as sodium potasium and calcium,which are responsible for the cardiac muscle contraction.

2. Why is Mrs. Kidway taking digoxin?

Digoxin is used to treat certain conditions of the heart like cardiac arrythmias especially atrial fibrillation and the congestive heart failure.It is clearly mentioned that Mrs Kidway has the history of CHF and there for she is taking the digoxin.In cases like congestive heart failure the heart is unable to pump aufficient blood to all parts of the body.It can be due to the decreased volume of the blood ejected due to the less force of contraction.But when we use the digoxin it can help the heart to pump more efficiently by increasing the force of cardiac contraction .This is happened due to the inhibition of the enzyme called ATPase and there by controlling the movement of the electrolytes which are responsible for the myocardial contraction.By this the heart rate will be controlled and the heart will be able to pump adequate blood to all parts of the body because of the increase in the force of contraction.

3. Given Mrs. Kidway’s digoxin level, briefly explain what electrolyte imbalance is of concern.

According to the given value of digoxin we can say that Mrs Kidway has digoxin toxicity.( the therapeutic level of digoxin is 0.6 -1.2 ng/ml.And here it is 3.8ng/ml.Digoxin toxicity can cause hyperkalemia since the digoxin decrease the rate of transportation of potasium into the cell from the blood .This will cause an increase in the level of potasium in the blood.As the level of digoxin increases the level of potasium also increases.

4. Does licorice interact with digoxin? If so, explain.

Yes,licorice can cause hypokalemia in the patient and this hypokalemia can cause the digoxin toxicity.Because usually the potasium and the digoxin get attached to the ATPase at the same side but when there is hypokalemia or decreased potasium in the blood it leads more and more digoxin get attached to the ATPase pump.This  enhances the therapeutic effect  and the toxicity of the digoxin.

5.Discuss what the terms loading dose and steady state indicate.

Loading dose is the higher dose of the drug which is given initially before staring the regular dose to achieve the therapeutic level in the blood rapidly.This is done for the medicines which has long half life,that means the drugs which take longer time to eliminate from the body.

Steady state is the time in which the drug concentration in the body stays consistent,or we can say invariable or we can say the level or the concentration of the drug remains the same.

6. What are the onset, peak, and duration times of digoxin when it is taken orally?

The oral dose of digoxin takes 30 minutes to 2 hours for the onset of its action.The peak time for the orally taken taken digoxin is 2 to 8 hours.The duration times is 2 to 4 days.(In the prescription we can see that the doctors mention it as 4/7 ,that means the drug should be taken continuously 4 days in a week and stop for the next 3 days and start taking the drug again after 3 days for the next consecutive 4 days )

7. If Mrs. Kidway was having difficulty swallowing her digoxin capsule and her health care provider changed her prescription to the elixir form of digoxin, theoretically would she still receive 0.125 mg?

Elixir formo of digoxin 100mcg is equal to the 125mcg of tablet digocin.

8. What is a medication’s “half-life”

Half life is the time take by the drug to eliminate half of its concentration from the body.The idea about the half life is important to calculate the steady state of the drug in the body and to calculate the time taken for its elimination from the body for maintaing the frequency of the drug to acquire and to maintain the steady state of a dug.

9.What is the half-life of digoxin?

For a healthy person with normal renal function the half life is 1.5 to 2 days,whereas in aperson with decreased urine out put or anuric the half life will be 3.5 to 5 days.

10.Theoretically, if Mrs. Kidway took her digoxin at 8:00 a.m. on a Monday, when will 75% of the digoxin be cleared from her body according to the half-life? Since the half-life of digoxin is prolonged in the elderly, use the high end of the range of digoxin’s half-life.

The half life of digoxin is 1.5 to 2 days,since the patient is elderly in this case we can consider it as 2 days.The time taken to eliminate the 50% is 2 days and the time taken to eliminate the next 25% is another 2 days .That means the digoxin takes 4 days to get eliminated 75% of it from the body.

(50% - 2days

remaining is 25%,this 25% is the half of the remaining concentration,so the time taken to become half of it is same as that of the half life that is 2 days.So total 4 days the digoxin takes to eliminate 75% of it from the body)