Lecture 4 Flashcards
What are pharmacokinetics and pharmacodynamics?
- PKinetics = what the body does to the drug.
- PDynamics: What the drug does to the body.
Dynamics = drug effect on body.
What 5 factors affect drug absorption?
- Altering stomach pH
- Inc/dec GI motility
- Mucosal damage
- Preventing absorption
- Reducing active transport mechanisms
What factors affect distribution of a drug?
- Increased adipose tissue
- Low total-body water content
- Decreased serum albumin
What factors affect metabolism of a drug?
- Reduced hepatic blood flow and liver size
- Use of a P450 inhibitor/inducer drug.
What factors affect excretion of a drug?
- Decreased renal tubular function
- Decreased GFR
What is polypharmacy?
Usage of multiple drugs to treat a single condition, often >5 drugs.
What are adverse reactions usually most related to the use of?
- Multiple medications
- Number of chronic illnesses present
How many hospitalizations occur each year in elderly patients?
14 million
What 2 medication classes are responsible for 2/3 of all medication related hospitalizations?
- Anticoagulants
- Hyperglycemics (Insulin)
What is the difference between an adverse drug reaction vs an event?
- Reaction = UNWANTED effect at normal dosage and use.
- Event = Injury/harm from use of a drug
Examples of ADRs: Bradycardia leading to syncope from BB use.
Diarrhea 2/2 abx use
Bleeding associated with anticoagulants.
What is the most common type of drug-drug interaction (DDI)?
P450 INHIBITION
2nd is P450 Induction.
What is a common drug that is used for HLD and is metabolized by P450?
Statins
Results in rhabdo if inhibited!!!
Why do BBs potentially cause an drug-disease interaction in COPD patients?
Underlying disease increases susceptibility to beta blockade, which could worsen their COPD.
How much does having additional providers increase ADR likelihood in poly-provider syndrome?
29% for every additional provider.
E-prescribing drugs is preferred, and only to one pharmacy!
What should we keep in mind regarding serum creatinine levels in elderly patients?
Older patients have less muscle mass and therefore produce less creatinine.
What 4 tools can we use to help prevent us from overprescribing to elderly patients?
- The Brown Bag Medication Review
- AGS Beers criteria
- STOPP
- START
STOPP = Screening tool of older patient’s prescriptions.
START = Screening tool to alert providers to right treatment.
What is brown bag medication review?
Having patients bring their medications so we can review them.
What are the 5 categories of drugs in Beers criteria?
- Drugs to avoid in most older patients
- Drugs to avoid in patients with specific health conditions
- Drugs to avoid in combo with other treatments
- Drugs to use in caution due to harmful side effect risk
- Drugs to dose differently due to renal insufficiency
What are the two most common drugs implicated in ER visits that result in ADRs?
- Warfarin
- Insulin
Specifically, avoid sliding-scale insulin!
Why are long-acting sulfonylureas more concerning in the elderly?
It has a longer clearance time in elderly, which may result in hypoglycemia.
Glipizide is the preferred sulfonylurea.
Why is digoxin a high-risk med?
Extremely narrow TI, making toxicity very common.
What are the risks of NSAIDs in elderly patients?
- PUD
- Renal impairment
- Exacerbates HTN
- Promotes fluid retention
What can we recommend to patients who chronically use NSAIDs?
Switching to tylenol or voltaren gel.
What are the anticholinergic side effects?
- Overheating, anhidrosis
- Dry mouth/eyes
- Blurred vision
- Flushed skin, tachycardia
- Hallucinations, dizziness, confusion
What is primary medication nonadherence?
Not picking up the prescription.
What is secondary medication nonadherence?
Not taking medications as prescribed.
