Polypharmacy Flashcards
What is polypharmacy?
The use of 5 or more medications regardless of clinical appropriateness
What is appropriate polypharmacy?
The prescribing of multiple medications for managing complex or multiple medical conditions
What is problematic polypharmacy?
The prescription of 5 or more medications which have not been appropriately considered:
-medications not appropriate
-causing ADRs
-meds have harmful interactions
What are the 3 main causes reasons why patients have polypharmacy?
Multiple health conditions
Elderly
Acute hospital admission
Why are the elderly at increased risk of suffering Adverse drug reactions from polypharmacy?
Reduced drug absorption
Reduced renal function
Higher fat percentage
Reduced liver function
How is absorption of drugs in the elderly reduced?
Less gastric acid secretion and impaired intestine mobility
How does reduced renal function put elderly patients at a higher risk of suffering Adverse drug reactions due to polypharmacy?
Reduced renal function means impaired drug elimination in the urine
So levels of drug in the blood stay higher
Why is a higher fat percentage in the elderly a risk factor for making them more likely to suffer with adverse drug reactions due to polypharmacy?
The higher fat percentage means the fat soluble drugs accumulate more in the body and get to higher levels
Drugs that are fat soluble have a higher volume of distribution
Why does reduced liver function in the elderly put patients at an increased risk of suffering Adverse drug reactions due to polypharmacy?
Reduced functional reserve of the liver with age means the patients metabolism of drugs by the liver is reduced so they can accumulate higher
What are the main complications of polypharmacy?
ADRs
Deaths
Falls (Hip fractures)
Delirium
Lethargy
Depression
Increased risk of prescribing cascade
What is the prescribing cascade>
When an adverse drug reaction is misinterpreted as a new disease and a new drug is prescribed
Patient has hypertension, hypothyroidism and T2DM. Medications:
-amlodopine
-thyroxine
-metformin
Patient has a fall and has leg swelling so is also prescribed 40mg furosemide
Later presents to AE with fall and AKI:
What has happened here?
Prescribing cascade
Patients leg swelling likely to do with amlodopines common side effects
Loop diuretic given since Doctor must’ve thought patient was overloaded when she wasn’t
This vasodilator lead to fall and pre renal AKI
What 2 drugs commonly cause ankle oedema as a side effect?
Amlodopine
Doxazosin
What class of drug is doxazosin?
Alpha blocker
Why does amlodopine and doxazosin cause ankle odema?
They act as vasodilators