Drug Use in the Elderly

2. It is much easier to write upon a disease than upon a remedy. The former is in the hands of nature and a faithful observer with an eye of tolerable judgement cannot fail to delineate a likeness. The latter will ever be subject to the whim, the inaccuracies and the blunder of mankind. William Withering (1741-1799)

3. A desire to take medicine is, perhaps, the great feature which distinguishes man from other animals.Sir William Osler, 1891

4. “I know of no way to end an office visit as satisfactorily and as efficiently as by writing a prescription. The patient knows that the visit is over and is expected to leave. He has something in his hand that he thinks will help him and obtaining it required an office visit.” Marcus Reidenberg, MD Editor Emeritus, CP&T

5. Drug Use in the Elderly • 57% of all elderly use > 5 drugs per week • 19% of elderly use > 10 drugs per week

6. Suboptimal Medication Use • Overuse • Inappropriate prescribing • Underuse Hanlon JT et al. JAGS. 2001;49: 200-9. Fisk D et al. Arch Intern Med. 2003;163: 2716-2724.

7. Polypharmacy Polypharmacy is not necessarily bad!

8. Drug Regimen Changes ~They are very common! • Any transition - hospitalizations, discharges, ER visits, subacute care stays • New meds, different doses… • Changes from generic to brand- nomenclature, color and/or shape

9. Why so many changes? • The more providers and visits, the more medications are prescribed • 2/3 of all physician visits end with a prescription • Expectations of the patient to receive a prescription • Lack of communication between prescribers • Self-treatment: unbeknownst to the physician

10. Impact on the Patient • Increased risk of adverse drug events and near-misses • Noncompliance or nonadherence leading to poor outcomes • Increased costs

11. Factors Influencing Drug Effects and Risk of Adverse Effects in the Elderly • Multiple co-existing illnesses • Polypharmacy: redundant effects and drug-drug interactions • Adverse drug effects nonspecific • Pharmacologic changes with aging • Medical error

12. Pharmacokinetics: Changes with Aging • Absorption • Distribution • Metabolism • Excretion

13. Body Composition Changes in Adult Men with Aging Data adapted from Cohn et al, 1980

15. Hepatic Metabolism of DrugsChanges with Aging • Phase I reactions- primarily oxidative reactions • Decline in efficiency with aging • Phase II reactions- conjugation reactions • No decline in efficiency with aging

16. Renal Function: Changes with Aging Creatinine Clearance Age

17. t1/2 ~ Vd/Clearance

18. Pharmacodynamics: Changes with Aging

19. Clinical Pearl Any new symptom in an elderly patient should be considered a drug side effect until proven otherwise. Jerry Avorn, MD

20. The Prescribing Cascade Drug 1 ADE Drug 2

21. The Prescribing Cascade Metoclopramide Extrapyramidal Effects Levodopa Rx

22. Case-Control Study Design CLASSIFY/COMPARE BEGIN Metoclopramide: Yes or No? L-dopa Rx Metoclopramide: Yes or No? Controls

23. Results Metoclopramide users were over three times more likely to begin use of L-dopa therapy compared with non-users (OR=3.09; 95% CI 2.25 to 4.26).

24. Likelihood of L-dopa Treatment by Metoclopramide Dose

25. Conclusion Metoclopramide confers an increased risk for the initiation of treatment generally reserved for the managment of idiopathic Parkinson’s disease. Avorn et al, JAMA, 1995

26. Improving the Quality of Prescribing to Older Adults • Medication reconciliation – at time of transitions • Anticipate errors – prescribing & monitoring • Watch out for prescribing cascades • Simplify the medication regimen • Identify obstacles (costs, cognitive impairment) • Enlist family/nursing/PCP support & involvement • Make sure there is good follow-up

27. Lessons from the Case