Problems Related To Durg use Elderly

1. Problems Related To
Drugs Use in ELDERLY

2. Ali Alaa El-Din Ali
Prepared by:

3. Outlines

4.  Age related changes that
may affect drug action.
 Reasons for Drug-Related
Problems.
Introduction.
 Drug-Related Problems in Older
Adults:
• Drug-disease interactions.
• Drug-drug interactions.
• Inadequate monitoring.
• Inappropriate drug selection.
• Lack of patient adherence.
• Over dosage.
• Poor communication.
• Under prescribing.
 Prevention of Drug-related Problems
in Elderly

5. Introduction
Drug-related problems are common in older adults and include:
A. Drug ineffectiveness.
B. Adverse drug effects.
C. Over dosage.
D. Under dosage.
E. Drug interactions.
A-Drugs may be ineffective in older adults because:
 Clinicians under-dose (e.g. because of increased concern about adverse effects)
 Adherence is poor (e.g. because of financial or cognitive limitations).
B-Adverse drug effects are effects that are unwanted, uncomfortable, or dangerous. Common
examples are:
 Over-sedation
 Confusion
 Hallucinations
 Falls
 Bleeding.

6. Drug ineffectiveness.
Adverse drug effects.
Over dosage.
Drug interactions.
Under dosage.
Drug-related problems are common in
older adults and include:

7. How age may
affect drug actions!
To understand the interaction between age, and
drugs, it is necessary first to define the
parameters that are involved in determining the
effect of drugs and how these parameters are
influenced by age and diet.
For a drug to exert a therapeutic effect on a
specific end organ, e.g. heart or brain, it must be
delivered to that end organ in appropriate
concentrations.

9. Pharmacokinetics
is best defined as what the body does to the drug; it includes ( Absorption - Distribution - Metabolism – Excretion ) ADME
1-Absorption:
With aging, there are changes in this area; some changes are more clinically relevant to:
Decrease in small-bowel surface area
Slowed gastric emptying
Increase in gastric PH (↓ gastric acidity) → ↓ calcium absorption
2-Distribution:
With age:
Body fat generally increases. → ↑ volume of distribution for highly lipophilic drugs (e.g. diazepam, chlordiazepoxide)
Total body water decreases. → ↑ volume of distribution for highly hydrophilic drugs (e.g. gentamicin)
NOTE: ↑ volume of distribution → ↓ Dose
3-Hepatic Metabolism
Age-related physiological changes that may account for the decrease in hepatic metabolism includes:
Reduction in liver mass.
Reduction in hepatic metabolizing enzyme activity. → ↓ metabolism of NSAIDs-Anticonvulsants.
Reduction in hepatic blood flow. (Up to 40%)
Reduction in first-pass metabolism (metabolism, typically hepatic, that occurs before a drug reaches systemic circulation) by about
1%/yr. after age 40.
NOTE: ↓ First-pass metabolism → ↑ Circulating drug concentrations → ↑ Risk of toxic effects. (e.g.
nitrates, propranolol, phenobarbital, and nifedipine)
4-Renal Elimination
One of the most important pharmacokinetic changes associated with aging is decreased renal elimination of drugs due to:
Decrease in GFR.
Decrease creatinine clearance an average of 8 mL/min/1.73 m2/decade after age 40.
NOTE: Creatinine clearance must be calculated for patients receiving drugs that predominantly excreted by the kidneys
(e.g. Aminoglycosides-Vancomycin-Atenolol-Digoxin)

10. Pharmacodynamics is defined as what the drug does to the body (Effect & Mechanism)
or the response of the body to the drug (Response), it is affected by:
Receptor binding.
Post-receptor effects.
Chemical interactions.
Differences may be due to:
Changes in drug-receptor interaction.
Post-receptor events.
Changes in adaptive homeostatic responses.
Pathologic changes in organs.
NOTE: By age → ↑ Sensitivity to CNS depressants → ↑ Risk for
adverse drug reactions. (Frequently prescribed drugs acting on
central nervous system, includes benzodiazepines-
Antidepressants-Antipsychotics-lithium)
↑ Sensitivity to warfarin → ↑ Risk for bleeding.

11. Adverse drug effects can occur in any patient, but certain characteristics of older adults
make them more susceptible.
For example, older adults often take many drugs and have age-related changes in
pharmacodynamics and pharmacokinetics; both increase the risk of adverse effects.
NOTE: In older adults, a number of common reasons for adverse drug effects,
ineffectiveness, or both are preventable.
Several of these reasons involve:
• Inadequate communication with patients
• Inadequate communication between health care practitioners (particularly during
health care transitions).
Many drug-related problems could be prevented if greater attention were given to
medication reconciliation when patients are admitted or discharged from the hospital or
at other care transitions (transfer from nursing home to hospital).
Reasons for Drug-Related Problems:

12. Drug-disease interactions.
Drug-drug interactions.
Inadequate monitoring.
Inappropriate drug selection.
Drug-Related Problems in Older Adults:
Lack of patient adherence.
Over dosage.
Poor communication.
Under prescribing.

13. 1-Drug-disease interactions.
A drug-disease interaction is an event in which a drug that is intended for therapeutic use,
exacerbates another disease regardless of patient age or (causes some harmful effects in
a patient because of a disease or condition that the patient has.)
Common Types of Drug-Disease Interactions:
Chronic Kidney Disease
Cardiovascular Disease
Digestive Disease
Antipsychotics may cause symptoms that resemble Parkinson disease. In older adults,
these symptoms may be diagnosed as Parkinson disease and treated with dopaminergic
drugs, possibly leading to adverse effects from the antiparkinsonian drugs (e.g. orthostatic
hypotension, delirium, hallucinations, nausea).

14. 2-Drug-drug interactions.
A change in a drug’s effect on the body when the drug is taken together with a
second drug. A drug-drug interaction can delay, decrease, or enhance absorption of
either drug.
This can decrease (Antagonism) or increase (Synergism) the action of either or both
drugs or cause adverse effects.
Because older adults often take many drugs, they are particularly vulnerable to
drug-drug interactions.
Older adults also frequently use medicinal herbs and other dietary supplements
and may not tell their health care providers.
Causes of unwanted drug effects and interactions
• Wrong choicedrug
• Failing to take account of renal function
• Wrong dosage / route of administration
• Errors in taking the drug
• of

15. 4-Inappropriate drug selection.
A drug is inappropriate if its potential for harm is greater than its potential for benefit.
Inappropriate use of a drug may involve
Choice of an unsuitable drug, dose, frequency of dosing, or duration of therapy
Duplication of therapy
Failure to consider drug interactions and correct indications for a drug
Appropriate drugs that are mistakenly continued once an acute condition resolves
(as may happen when patients move from one health care setting to another)
Some classes of drugs are of special concern in older adults.
Some drugs are so problematic that they should be avoided altogether in older
adults: regular, long-term use of NSAIDs→ ↑ risk of bleeding stomach ulcers.
Some should be avoided only in certain situations: Avoid nephrotoxic drugs in case
of CKD.
Some can be used but with increased caution: Use with caution Digoxin (Lanoxin)
→Can be toxic in older adults and people whose kidneys do not work well as it
excreted by kidney →↑ in blood into toxic levels.

16. 5- Lack of patient adherence.
Drug effectiveness is often compromised by lack of patient adherence among the
ambulatory older adults.
Adherence is affected by many factors including:
Financial and physical constraints, which may make purchasing drugs difficult
Cognitive problems, which may make taking drugs as instructed difficult
Use of multiple drugs
Use of drugs that must be taken several times a day or in a specific manner
Lack of understanding about what a drug is intended to do (benefits) or how to
recognize and manage adverse effects (harms)
Clinicians should assess patients’ health literacy and abilities to adhere to a drug
regimen (e.g., dexterity, hand strength, cognition, vision) and try to accommodate
their limitations as:
Arranging for or recommending easy-access containers
Drug labels and instructions in large type
Containers equipped with reminder alarms
Containers filled based on daily drug needs
Reminder telephone calls
Medication assistance.

17. 6-Over dosage.
An excessive dose of an appropriate drug may be prescribed for older adults if the
prescriber does not consider age-related changes that
affect pharmacokinetics and pharmacodynamics.
For example, doses of renally cleared drugs should be adjusted in patients with
renal impairment.
Generally, although dose requirements vary considerably from person to person,
drugs should be started at the lowest dose in older adults.
Typically, starting doses of about one third to one half the usual adult dose are
indicated when a drug has a narrow therapeutic index, when another condition may
be exacerbated by a drug, and particularly when patients are frail.
The dose is then titrated upward as tolerated to the desired effect.
When the dose is increased, patients should be evaluated for adverse effects, and
drug levels should be monitored when possible.

18. 7-Poor communication.
Poor communication of medical information at transition points (from one health care
setting to another) causes up to 50% of all drug errors and up to 20% of adverse
drug effects in the hospital.
When patients are discharged from the hospital, drug regimens that were started
and needed only in the hospital (e.g., sedative hypnotics, laxatives, proton pump
inhibitors) may be unnecessarily continued by another prescriber, who is reluctant to
communicate with the previous prescriber.
Conversely, at admission to a health care facility, lack of communication may result
in unintentional omission of a necessary maintenance drug.
NOTE: Drug reconciliation refers to a formal process of reviewing all prescribed
drugs at each transition of care and can help eliminate errors and omissions.

19. 8-Under prescribing.
Appropriate drugs may be under prescribed—ie, not used for maximum
effectiveness.
Under prescribing may increase morbidity and mortality and reduce quality of life.
Clinicians should use adequate drug doses and, when indicated, multidrug
regimens.
Drugs that are often under prescribed in older adults include those used to treat
depression, Alzheimer disease, pain (eg, opioids), heart failure, post-MI (beta-
blockers), atrial fibrillation (warfarin), hypertension, glaucoma, and incontinence.
NOTE: Also, immunizations are not always given as recommended.

20. Opioids: Clinicians are often reluctant to prescribe opioids for older patients with
cancer or other types of chronic pain, typically because of concerns about adverse
drug effects (e.g., sedation, constipation, delirium) and development of dependence.
When opioids are prescribed, the doses are often inadequate. Under prescribing
opioids may mean that some older patients have needless pain and discomfort;
older adults are more likely to report inadequate pain management than younger
adults.
Beta-blockers: In patients with a history of MI and/or heart failure, even in older
patients at high risk of complications (e.g., those with pulmonary disorders or
diabetes), these drugs reduce mortality rates and hospitalizations.
Antihypertensives: Guidelines for treating hypertension in older adults are
available, and treatment appears to be beneficial (reducing risk of stroke and major
cardiovascular events). Nonetheless, studies indicate that hypertension is often not
controlled in older patients.

21. Prevention of Drug-related
Problems in Elderly

22. Before starting a new drug:
After starting a drug
Ongoing

23. A-Before starting a new drug:
To reduce the risk of adverse drug effects in older adults, clinicians should do the following
before starting a new drug:
 Consider nondrug treatment
 Discuss goals of care with the patient
 Document the indication for each new drug (to avoid using unnecessary drugs)
 Consider age-related changes in pharmacokinetics or pharmacodynamics and their
effect on dosing requirements
 Choose the safest possible alternative (e.g., for no inflammatory
arthritis, acetaminophen instead of an NSAID)
 Check for potential drug-disease and drug-drug interactions

24. CONT
 Start with a low dose
 Use the fewest drugs necessary
 Note coexisting disorders and their likelihood of contributing to adverse drug effects
 Explain the uses and adverse effects of each drug
 Provide clear instructions to patients about how to take their drugs (including generic and brand names,
spelling of each drug name, indication for each drug, and explanation of formulations that contain more
than one drug) and for how long the drug will likely be necessary
 Anticipate confusion due to sound-alike drug names and pointing out any names that could be confused
(e.g., Glucophage®and Glucovance®)

25. B-After starting a drug
The following should be done after starting a drug:
Assume a new symptom may be drug-related until proved otherwise (to prevent a
prescribing cascade).
Monitor patients for signs of adverse drug effects, including measuring drug levels
and doing other laboratory tests as necessary.
Document the response to therapy and increase doses as necessary to achieve
the desired effect.
Regularly reevaluate the need to continue drug therapy and stop drugs that are no
longer necessary.

26. C-Ongoing
The following should be ongoing:
Medication reconciliation is a process that helps ensure transfer of information
about drug regimens at any transition point in the health care system. The process
includes identifying and listing all drugs patients are taking (name, dose, frequency,
route) and comparing the resulting list with the physician’s orders at a transition
point. Medication reconciliation should occur at each move (admission, transfer,
and discharge).
Computerized physician ordering programs can alert clinicians to potential
problems (e.g., allergy, need for reduced dosage in patients with impaired renal
function, drug-drug interactions). These programs can also cue clinicians to
monitor certain patients closely for adverse drug effects.

27. References

28. • Tam VC, Knowles SR, Cornish PL, et al: Frequency, type and clinical importance of medication
history errors at admission to hospital: a systematic review. CMAJ 173(5):510-5, 2005.
doi: 10.1503/cmaj.045311.
• Wong JD, Bajcar JM, Wong GG, et al: Medication reconciliation at hospital discharge: evaluating
discrepancies. Ann Pharmacother42(10):1373-9, 2008. doi: 10.1345/aph.1L190.
•
• The American Geriatrics Society 2015 Beers Criteria Update Expert Panel: American Geriatrics
Society updated Beers Criteria for potentially inappropriate medication use in older adults.
63(11):2227-46, 2015. doi: 10.1111/jgs.13702.
•
• Hanlon JT, Semla TP, Schmader KE, et al: Alternative medications for medications in the use of
high-risk medications in the elderly and potentially harmful drug-disease interactions in the
elderly quality measures. J Am Geriatr Soc 63(12): e8-e18, 2015. doi: 10.1111/jgs.1380
•
• https://www.drugbank.ca/drugs/DB09389.
•
• https://pubchem.ncbi.nlm.nih.gov/compound/norgestrel#section=Toxicity.

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