Week 3: Medications and Other Bioactive Substances

Pharmocokinetics

How a drug is absorbed, distributed, metabolized and excreted

Pharmacodynamics

How the body is affected by a drug at the cellular level and in relation to the target organ

Elimination/Serum half life

The time required to decrease the drug concentration by one half of its original value

- Determines when you can take your next dose

What can affect the pharmacokinetics of the absorption of an oral medication

- Reduced gastric acid

- Increased gastric pH

- Delayed gastric emptying

- The presence of other substances in the stomach (ex. Food)

How many half lives does it take to reach steady-state/fully eliminate drug from the body

5 half-lives

What are age related physiological changes that affect the action of medications in older adults

- Decline in renal function

- Decline in hepatic blood flow

- Decreased muscle mass and water content (determines half-life)

- Low serum albumin (protein)

- Altered receptor sensitivity

What affects medication taking behaviour?

1. Cultural and psychosocial influences

2. Ability to swallow oral preparations

3. Motivation

4. Physical ability to remove the substance from the container to administer it

5. Additional skills related to administer nasally, transdermally, SC and by other routes

6. Knowledge about the medication

What is polypharmacy?

- The use of more medications than are clinically indicated/necessary

- This does not only focus on the number of medication

- Instead its about the appropriateness and combination of medications

Why is it important to pay attention to the side effects of medications with older adults?

- All medications have side effects

- Older adults are more likely to experience stronger side-effects

- Always consider whether the benefit outweighs the risk

What are 6 functional consequences associated with medications in older adults

- Disease or polypharmacy may alter the therapeutic effects of a medication

- Adverse effects

- Anticholinergic adverse effects

- Altered mental status (pain meds, narcotics, opioids)

- Antipsychotics in people with dementia

- Tardive Dyskinesia and drug-induced Parkinsonism

What are factors that increase older adults risk for adverse events

- Higher number of medications

- Malnourishment or dehydration

- Multiple comorbidities

- An illness that interferes with cardiac, renal or hepatic function

- Cognitive impairment

- History of medication allergies or adverse effects

- Fever that can alter the action of certain medications

- Recent change in health

- Certain medications: anticoagulants/antiplatelets, antidiabetics, NSAID's, CNS drugs

What is an anticholinergic

- Drugs that block the action of acetylcholine, a neurotransmitter or chemical messenger that transfers signals between certain cells to affect how your body functions.

- They inhibit the parasympathetic (stabilizing) nervous system

What drugs have anticholinergic properties

- OTC medications for coughs, colds, flu and sleep problems

- Antihistamines

- Antidepressants

- Antipsychotics

- Antiparkinsonians

- CV agents

- GI and urinary agents

What are negative effects of anticholinergics

- Contribute to long-term cognitive impairment

- Can counteract the effects of cholinesterase inhibitors, a primary treatment for dementia

- Safer alternatives usually exist; try to advocate for them

Where are anti-psychotics used

- Increasingly used in LTC facilities

- Research shows nursing staff need more knowledge for its use in LTC facilities

What is tardive dyskinesia and when does it occur?

- Rhythmic involuntary movements of the trunk, extremities, jaw, lips, mouth or tongue.

- Wormlike movements of the tongue, chewing, grimacing, lip smacking, jaw clenching, eye blinking, and side to side jaw movements

- Can begin 3-6 months after initiation of antipsychotic use and persist after medication is discontinued

What is drug-induced Parkinsonism

- Parkinson-like symptoms such as shaking, involuntary or poorly controlled movements that is caused by certain medications

- Condition can be easily misdiagnosed as Parkinsonism and patients are started on new medications

- Manifestations can be reversed if the drug is stopped

What is BEERS

- A list of medications known to increase the risk of delirium and other adverse reactions in older adults

- These medications should not be prescribed for older adults unless there is a greater benefit-risk ratio for a particular situation, and then should only be used for the shortest possible duration

What are the goals of assessment

- Determine effectiveness of existing regimen

- Identify any factors that interfere with current regimen

- Ascertain risks for adverse effects or altered therapeutic actions

- Detect adverse medication effects

- Identify teaching needs regarding medications

What is the scope of medication assessment

Looking at everything a person takes:

- Prescription and OTC medications taken regularly

- Medications taken PRN

- Vitamins, minerals and dietary supplements

- Herb and Folk remedies and complementary/alternative modalities

- Alcohol, substances

- Smoking/inhaling

What is medication reconciliation?

Identifying medications at any transition in care:

- View all the medications

- Address ability to get prescriptions filled

- Address issues that affect adherence

- Allow the client to ask questions

What are some nursing interventions for medications

- Recommend all older adults have a list of what they are currently taking

- Ensure clients and caregivers understand the appropriate use of "as needed" (PRN)

- Encourage use of devices and systems to improve medication adherence (ex. Pill boxes, blisterpacks)

- Encourage nonpharmacologic approaches to manage behaviour

- Decreases number of medications

- Assess for financial barriers: Generic vs brand

What are interdisciplinary interventions

- Encourage a review of medications with primary physician at every visit

- The pharmacist's role is to review specific actions and interactions of medications

- Advocate for referral to senior clinic for follow up of complex clients

- Refer to home care if assistance is required for medication administration

- Social worker referral for assistance with financing