Pharmacology: A Case Study in Polypharmacy

Mrs A is a 71 year old widow with CCF and osteoarthritis who has recently been exhibiting quite unusual behaviour. Her daughter is concerned about her mother’s ability to remain independent and wishes to pursue nursing home admission arrangements. She fears the development of a dementing illness. Over the last two to three months Mrs A has become confused, easily fatigued and very irritable. She has developed disturbing obsessive/compulsive behaviour constantly complaining that her lace curtains were dirty and required frequent washing. Detailed questioning revealed that she thought they were yellow-green and possibly mouldy. Her prescribed medications are:

* Frusemide 40 mg daily in the morning

* Digoxin 250 micrograms daily

* Paracetamol 500 mg, 1-2 tablets 4-hourly PRN

* Piroxicam 20 mg at night

* Mylanta suspension, 20 ml PRN

* Coloxyl 120 mg, 1-2 tablets at night

Critically discuss this case study in terms of the problematic nature of this patient’s pharmacological management.

Your answer should include a discussion of the problems of polypharmacy as it is related to this case study and the assessment/management and educational strategies which could have been implemented to improve the outcome of Mrs A.

Introduction

In analyzing the case study of Mrs A, a number of factors come into play. The patient has recently been exhibiting unusual symptoms including confusion, fatigue, irritability and apparent obsessive/compulsive behaviour. Her daughter fears the onset of a dementing illness. However, upon close examination of Mrs A’s prescribed medications, very different conclusions can be drawn.

Overview of each Mrs A’s medical conditions

The Online Medical Dictionary at www.mydr.com.au defines CCF as a condition where there is ineffective pumping of the heart leading to fluid retention and organ congestion. The site defines osteoarthritis as “Noninflammatory degenerative joint disease occurring chiefly in older persons.” There are various drug treatments available for these conditions.

Polypharmacy and Mrs A’s problematic pharmacological management

A close examination of Mrs A’s drugs, serves to reveal the problematic nature of her pharmacological management and the results of polypharmacy.

Frusemide 40 mg daily in the morning

Loeb, S (2001:649) includes the following factors in his outline of frusemide.

Indications & dosage: Hypertension – adults 40 mg P.O. b.i.d. Adjust dose according to response.

Adverse reactions: Hypokalemia (low potassium), fluid and electrolyte imbalances.

Relevant interactions: Care should be exercised in patients receiving potassium depleting agents.

Nursing considerations: Monitor serum potassium level. Watch for signs of hypokalemia (for example fatigue, muscle weakness and cramps). Give P.O. and I.M. preparations in a.m. to prevent nocturnia.

Applications to case study

It is likely that frusemide is being given to Mrs A as diuretic therapy to treat fluid retention typically associated with Congestive Cardiac Failure. Mrs A’s dose of 40 mg daily in the morning is a standard initial dose however it should be adjusted according to response. Morning dose is correctly implemented to alleviate sleeplessness and reduce gastric disturbance.

Frusemide could be increasing Mrs A’s sensitivity to digoxin. As such, an alternate drug such as Zantac may be advisable. Moreover, a high potassium diet may help reduce potassium loss and the risk of hypokalaemia whilst eliminating the need for potassium supplements. Mrs A needs to be monitored for symptoms of hypokalaemia and her serum potassium levels checked.

Digoxin 250 micrograms daily

McKenry, L & Salerno, E (1989:454-458) includes the following factors in their outline of digoxin.

Indications & dosage: In elderly patients, an initial dose of 500 to 750 micrograms may be given as a single dose. Maintenance dose for adults over 65 years is 125 micrograms P.O. daily and for frail or underweight elderly patients this may be only 63 micrograms daily or 125 micrograms every other day.

Adverse reactions: Fatigue, muscle weakness, agitation, yellow-green visual disturbance, gastric irritation, arrhythmias.

Relevant interactions: Diuretics – hypokalemia, predisposing patient to digitalis toxicity. Antacids – decreased absorption of oral digoxin.

Nursing considerations: Obtain baseline data (heart rate and rhythm, blood pressure, and electrolytes) before giving first dose. Dose is adjusted to patient’s clinical condition and is monitored by serum levels of cardiac glycoside, calcium, potassium, magnesium, and by ECG. Check for symptoms of toxicity.

Applications to case study

Digoxin is being used to treat Mrs A’s CCF. The dose of 250 micrograms daily far exceeds the regular maintenance dose for a patient of her age. It is thus almost certain that Mrs A is suffering from digoxin toxicity which is most likely being compounded by taking frusemide. Mrs A’s symptoms of confusion, fatigue, irritability and visual disturbance are symptomatic of digoxin poisoning. Mylanta (also being taken by the patient) can suppress the effectiveness of digoxin however in this case the digoxin dose is so high that Mylanta would be having a minimal impact.

Mrs A’s digoxin dose must be adjusted to her clinical condition and her serum levels monitored. Digoxin should be taken with meals to decrease the effects of gastric irritation that can accompany treatment. Frusemide and digoxin can both cause hypokalemia; this can be controlled by encouraging Mrs A to eat potassium-rich foods, instructing her about dosage regimen, reportable signs of digitalis toxicity, and follow up plans.

Paracetamol 500 mg, 1-2 tablets 4-hourly PRN

Loebl, S et al (1994:813-815) includes the following factors in their outline of paracetamol.

Indications & dosage: Adults and children over 11 years – 325 mg to 650 mg P.O. q 4 hours; or 1 g P.O. q.i.d. p.r.n. Maximum dosage should not exceed 4 g daily. Dosage for long term therapy should not exceed 2.6 g daily.

Adverse reactions: severe liver damage with toxic doses, rash.

Relevant interactions: None.

Nursing considerations: Has no significant anti-inflammatory effect. Warn
patient that high doses can cause hepatic damage.

Applications to case study

It is possible that paracetamol is being given to Mrs A to treat the pain associated with her osteoarthritis, or for headache which may be a side effect of piroxicam administration. The dose being taken is relatively high. Paracetamol does not react adversely with the other drugs being taken by Mrs A, however her dose must be monitored and adjusted according to need. The nurse needs to assess why Mrs A is taking paracetamol and whether it is beneficial.

Piroxicam 20 mg at night

Brody, T et al (1994:397) includes the following factors in his outline of piroxicam.

Indications & dosage: 20 mg P.O. once daily. If desired, the dose may be divided.

Adverse reactions: Headache, drowsiness, nausea, epigastric distress, peptic ulceration, nephrotoxicity.

Relevant interactions: None.

Nursing considerations: Use cautiously in elderly patients and patients with cardiac disease. Check renal, hepatic, and auditory function periodically during prolonged therapy. Drug should be discontinued if abnormalities occur.

Applications to case study

Piroxicam is an arthritis medication and is being used to treat Mrs A’s osteoarthritis. The 20 mg dose is standard. Brody, T et al (1994:397) does not recommend a time of day for taking the medication however scheduling with meals may reduce the drug’s possible adverse reactions – which include epigastric distress and peptic ulceration. Because epigastric distress and peptic ulceration is another possible side effect of piroxicam, the patient needs to be monitored for these symptoms.

Mylanta suspension, 20 ml PRN

The MIMS Annual (2000:1-7) includes the following factors in its outline of Mylanta.

Indications & dosage: Liquid 10 to 20 ml three to four times daily, preferably between meals and at bedtime.

Adverse reactions: Constipation or diarrhoea have rarely been reported with the use of Mylanta.

Interactions: Concomitant use of antacid preparations may alter the absorption profiles of a wide variety of drugs. Potential for adverse reaction with digoxin.

Nursing considerations: Use cautiously in elderly patients. Record amount and consistency of stools. Warn patient not to take Mylanta indiscriminately or switch antacids without doctor’s advice.

Applications to case study

Mylanta is possibly being used to treat the side effects of piroxicam – epigastric distress and peptic ulceration. If Mrs A has these symptoms, they could be managed with alternate medications such as Losec or H2 histamine receptor blockers and/or a regulated diet.

Coloxyl 120 mg, 1 – 2 tablets at night

The MIMS Annual (2000:1-20) includes the following factors in its outline of Coloxyl.

Indications & dosage: Adults – two 120 mg tablets once a day after evening meal.

Adverse reactions: Prolonged use may lead to diarrhoea, with excessive loss of water and electrolytes, particularly potassium.

Nursing considerations: Should only be used occasionally. Don’t use for more than 1 week without doctor’s knowledge.

Applications to case study

It cannot be determined from the case study any reason for Mrs A requiring a stool softener. If Mrs A is suffering from constipation, alternate treatments could be tried before resorting to medications. Diet can be managed to increase fibre levels and promote stool movements.

The problems of polypharmacy in Mrs A’s case

Gailbraith, A, Bullock, S & Manias, E, (2001:15) outlines the major symptoms of polypharmacy and defines it as “the excessive and unnecessary use of medications”. Elderly patients like Mrs A are particularly susceptible to this problem.

Use of medications with no apparent indication

Mrs A is taking drug therapy for conditions not diagnosed. The main example of this is her use of Coloxyl. No reason is evident in the case study as to why she should require a stool softener.

Use of duplicate medications

Mrs A may be receiving duplicated medications for the same symptom. It is possible that paracetamol and piroxicam are both being used to treat the same symptoms of her osteoarthritis. There is no apparent reason given in the case study as to why she is taking paracetamol.

Concurrent use of interacting medications

There are several examples of this in Mrs A’s case. The most noticeable is her use of frusemide with digoxin. Frusemide is known to increase digoxin sensitivity.

Use of contraindicated medications

Medications taken that are not appropriate to a particular condition can result in aggravation of other existing conditions. Mrs A’s use of Coloxyl could further aggravate the gastric upset that can be a side effect of frusemide, digoxin and piroxicam use.

Use of inappropriate dosage

Mrs A is receiving an excessive dose if digoxin. This is causing symptoms of digoxin poisoning.

Use of drug therapy to treat adverse drug reactions

Mrs A’s treatment also falls into this category. She is most likely being treated with Mylanta suspension to alleviate epigastric distress/peptic ulceration caused by piroxicam.

Assessment, management & educational strategies that would have improved the outcome for Mrs A

Application of the clinical decision making process would have prevented the polypharmacy problems faced by the patient. Loeb, S. 2001 (2001:22-26) outlines the 5 steps of the clinical decision making process:

Assessment

The nurse focuses on direct data collected by:

Obtaining drug history

Reviewing Mrs A’s previous medical history (including physical, psychosocial and emotional status)

Performing a physical examination

Obtaining relevant laboratory or diagnostic test results

Formulating a nursing diagnosis

Using information gathered during assessment, define any potential or actual drug-related problems. The most common statements related to drug therapy are “Knowledge deficit”, “Noncompliance” and “Alteration in Health Maintenance”.

Planning

Planning should ensure Mrs A’s needs are being met – including nutrition and hygiene; that her condition is being monitored, and that tests are being carried out as ordered.

Intervention/Education

After developing the outcome criteria, the nurse determines the interventions needed to help Mrs A reach the desired behaviour and goals. Drug related interventions may focus on education strategies about a drug’s action, adverse effects, scheduling, steps to avoid, treating drug reaction, as well as drug administration techniques – including compliance.

Evaluation

This is a systematic process for determining the effectiveness of nursing care. In regards to Mrs A’s case, this would entail monitoring of observations and tests to determine their effectiveness and the evaluation of any adverse effects.

Conclusion

The patient’s pharmacological management seems problematic and needs to be analysed. This analysis needs to take into account the main problems of polypharmacy – such as use of medications with no apparent indication, concurrent use of interacting medications and use of inappropriate dosage. It can thus be revealed that implementation of assessment/management and educational strategies – like the Clinical Decision Making Process, would significantly improve the outcome for Mrs A.

Reference List

Brody, T et al Ed 1994, Human Pharmacology. St Louis: Mosby

Gailbraith, A, Bullock, S & Manias, E, Ed 2001, Fundamentals of Pharmacology. A textbook for nurses and allied health professionals. Australia: Addison-Wesley

Loeb, S. 2001, Nursing 2001 Drug Handbook. Pennsylvania: Springhouse Corporation

Loebl, S, Spratto, G & Woods, A, Ed 1994, The Nurse’s Drug Handbook. Delaware: Delmar Publishers Inc.

McKenry, L & Salerno, E, Ed 1989, Mosby’s Pharmacology in Nursing St Louis: The C.V. Mosby Company

MIMS Annual 2000 Ed 24. Sydney: MediMedia Australia

My Doctor http://www.mydr.com.au