Geriatrics - prescribing in the elderly Flashcards
how do adr’s look like growing old?
unsteadiness, dizziness, confusion, nervousness, fatigue, insomnia, frowsiness, falls, depression, incontinence.
use hyperthyroidism to describe how conditions have different presenting signs in elderly patients.
young patient - tremor, anxiety, weightloss, diarrhoea./ elderly patient - depression, cognitive impairment, ,muscle weakness, atrial fibrillation, muscle weakness, heart failure, angina.
what are the sigjnm management guidelines for DM with hypertension?
HbA1c <7% or individualised
BP<130/80: use ACEI > ARB > Ca Ch blockers > thiazide
Avoid alpha- and beta-blockers / Statins for all aged over 40 years / Aspirin for secondary prevention only / Not forgetting lifestyle advice!
What healthcare provider factors contribute to polypharmacy?
No med review with patient on regular basis
Presumes that patient expects meds
Prescribes without sufficiently investigating clinical situation
Evidence that a particular drug is the “best” drug for a problem
Complicated by the existence of many problems and multiple providers
Provides unclear, complex or incomplete instructions about how to take meds
No effort to simplify medication regimen
Ordering automatic refills
Medications promoted and publication bias
Lack of knowledge of geriatric clinical pharmacology
how does change in body compositionn annd protein binding effect drug distribution
Body composition changes
Reduced muscle mass
Increased adipose tissue- Fat soluble drugs: ↑ Vd, ↑ T1/2, ↑ duration of action e.g. diazepam
Reduced body water: Water soluble drugs: ↓Vd, ↑ serum levels e.g. digoxin
Protein binding changes, Decreased albumin: ↓ binding, ↑ serum levels acidic drugs e.g. furosemide
Increased permeability across the blood-brain barrier
liver metabolism of drugs lowered and what are the connsequences
Toxicity due to reduced metabolism/excretion
Reduced first pass metabolism: ↑ in bioavailability with some drugs e.g. propranolol/ Can cause ↓ bioavailability of pro-drugs e.g. enalapril
renal excretion is lowered, clearance isdecreased annd half life is increased, leadinng to toxicity.
how are pharmacodynamics effected?
inncreased sensitivity due to decrease inn receptor numbe. Altered translation of a receptor initiated cellular response into a biochemical reaction.
Examples: diazepam (↑ sedation), warfarin (↑ anti-coagulation)
What are prescribing tools and guides?
Beer’s criteria, STOPP-START criteria, NHS scotland polypharmacy guidance
Deprescribing is also done (reduce, substitute or discontinue a drug)
