Pharmacology small group student notes - 1
Johnston
Student Notes
Pharmacology in Older Adults
Small Group Session
Created by Bree Johnston, Anna Chang, and Helen Chen
Division of Geriatrics, UCSF
USEFUL RESOURCES
Katzung,’s Basic & Clinical Pharmacology, 8th Edition
Pharmacokinetics & pharmacodynamics, pp. 35-50
Cockroft-Gault formula: pp. 1037-1038
Digoxin toxicity and management: p. 1021
Volume of distribution: pp. 35, 1011
Loading dose: p. 46
Maintenance dose: p. 45
Variation in drug responsiveness: pp. 30-31, 1036-1038
Online Drug Pricing
Online Drug Interaction Facts
Online GFR Calculator
INSTRUCTIONS
Before coming to small group, prepare answers to the questions for Case 1. For case 1, find out through an online or PDA resource how much the medication regiment would cost. Try to enroll her in a Medicare D program on , and tell us how much money she could be expected to save (or not).
After reviewing Case 1, you will work through several other cases and associated questions. Please bring a calculator, a pharmacology textbook or a PDA based pharm program such as Epocrates.
Case #1:
Mrs. BJ is an 80 year old woman with CAD, status post non - ST segment elevation myocardial infarction 6 months ago. She also has Type 2 diabetes, hypertension, COPD, osteoarthritis, and hypercholesterolemia. Following her MI, a persantine thallium test showed a fixed perfusion defect inferiorly but no other abnormalities, and she continued on medical management. Two months ago she was found to have severe osteoporosis, and treatment was begun for that.
You see her in you continuity clinic, and she says she is doing well. You note that her blood pressure is 160/88, Pulse 80 R 18 and glycosylated hemoglobin level is 9.0%.
She is retired, widowed, and lives alone. Her children live far away. She is still at home, but is having more difficulty getting around and paying bills. Somebody comes in to clean her house once a week.
Her Current medications are:
Fluticasone Inhaled BID
Albuterol/iprratropium (Combivent) Inhaler QID
Alendronate 70mg weekly
Metformin from 500mg PO twice daily
Amlodipine from 5mg QD.
Glynase prestabs 6mg PO QAM
Celecoxib 200mg po QD
Simvastatin 20mg po QD
ASA 325mg po QD
Metoprolol 100mg BID
Fosinopril 10 mg po QD
Calcium carbonate 500mg po BID and Multivitamins one daily
You decide to increase her metformin from 500mg PO twice daily BID to 500mg PO three times daily and her amlodipine from 5mg to 10mg QD. Her other medications are continued.
At follow up three months later her blood pressure is 166/92, Pulse 78 and glycosylated hemoglobin is 9.2%.
Case #1 Questions:
1. What are possible explanations for her lack of response to blood pressure and anti-hypertensive therapies?
2. How would you explore this further?
3. How much would this medication regimen cost? What resources would help you determine the cost of medications?
4. What steps could you take to try to improve her blood pressure and glucose control?
Handout #2 (To be handed in Small Group)
CASE #2
An 70-year-old (white) man with coronary artery disease and congestive heart failure comes in for a regular appointment. He has been having gradually increasing nausea, anorexia, fatigue, and inactivity over a few months. He reports no shortness of breath or chest pain. He has been on the same medical regimen for ten years:
Digoxin .125 mg PO QD
Furosemide 40 mg PO QD
Lisinopril 40 mg PO QD
Atenolol 50 mg PO QD
ASA 325 mg PO QD
His weight has declined over the past year from 70kg to 60kg. His creatinine level had been stable over the past ten years at 1.4, but is 1.8 today. His last digoxin level two years ago was normal at 1.0.
Today he appears somewhat thin. BP 140/80, HR 60 and regular, remainder of examination is normal.
10 years agoToday
Wt. 70 kg60 kg
Cr1.41.8
BUN 2032
Alb4.03.8
Case #2 Questions
A.What changes in pharmacokinetics can you expect to see with aging?
B. Based on the MDRD equation, what was his estimated glomerular filtration rate 10 years ago and what is it today?
C. Based on the Cockroft-Gault equation, what was his estimated creatinine clearance 10 years ago and what is it today?
D.Are there any important drug interactions in his regimen?
E. What are possible explanations for his symptoms?
F.How would you adjust his medications?
G.(optional) About how much does he pay for his medications every month?
Handout #3 (To be handed in Small Group)
CASE #3
You are a new intern. Mr. P is an 80 year old Filipino who you are just picking up from the finishing resident. He is here for an acute appointment because his wife says that he became confused and started experiencing visual hallucinations two days ago. She denies that he has fever, chest pain, cough, pain, diarrhea, nausea, vomiting, or any other new or obvious symptoms. His vital signs are BP 150/88, P 64, R 16. His general examination is normal. Neurologic examination is significant for cogwheel rigidity and fluctuating mental status. He is unable to complete a mini-mental state exam because he keeps losing attention.
You review his medical record and find the following:
4 months ago He is noted to have complaints of GERD and BP of 160/90.
Started on HCTZ 25 mg PO QD and omeprazole 20mg PO QD.
2 months ago Comes in with gout attack on Right MTP
BP 140/85
No further heartburn symptoms
Piroxicam 20mg QD added
6 weeks ago Gout flare is improved
Complaining of more GI distress again
BP again up at 160/90
Metoprolol 25mg BID added.
Omeprazole increased to 40mg PO QD
Referred to GI
4 weeks agoGI endoscopy reveals esophagitis and gastritis
Metoclopromide 10mg PO TID added to his regimen.
2 weeks agoGI symptoms better.
Exam reveals Parkinsonism
Sinemet 25/300 TID added.
Medication list today:
Piroxicam 20mg po QD
Ompeprazole 40mg PO QD
Metoclopromide 10mg PO TID
HCTZ 25mg PO QD
Metoprolol 25mg PO BID
Sinemet 25/100 TID
Questions
1. Were any medication errors made in this case?
2. Could medications be causing any of his symptoms? Which ones?
3. How could you clean up this mess?
LEARNING OBJECTIVES (to be handed out at the end of the session)
Case #1:
1. Recognize medication nonadherence as a possible explanation of lack of therapeutic benefit
2. List common sources of non-adherence
3. Discuss effective methods for exploring nonadherence with a patient
4. Discuss the importance of drug prices as a potential cause of non-adherence, and list strategies for dealing with this issue
5. (Optional: discuss policy issues surrounding drug marketing and pricing, the physicians’ role, and Medicare Part D)
Case #2:
1. List physiologic changes in elders that impact pharmacokinetics of commonly used drugs
2. Use the MDRD to calculate the decline in renal function with aging, and describe its advantages over the Cockroft and Gault equation
3. Use the “Cockroft and Gault” equation to estimate the decline in renal function with aging and describe advantages and limitations of this tool
4. Recognize symptoms of digoxin toxicity
5. Gain an awareness of the range of costs of medications, appreciating how much cheaper “older” and generic drugs can be than newer brand name drugs
Case #3:
1. Define polypharmacy in the context of appropriate drug prescribing
2. Describe adverse consequences of polypharmacy, including drug-drug interactions, side effects, and a “prescribing cascade”
3. Discuss the importance of exploring medications as a potential cause of new or unexplained symptoms