Drugs and Polypharmacy Flashcards
What are some common iatrogenic drug problems?
Confusion, dry mouth, constipation, blurred vision, urinary retention, orthostatic hypertension, confusion, digoxin toxicity and CNS toxicity with long acting benzodiazepines
What are common ADRs in older patients?
Falls, cognitive loss, dehydration, incontinence and depression which can lead to loss of functional capacity and poor QoL
What are some healthcare provider factors that contribute to polypharmacy?
No med review, unclear instructions on how to take meds, no effort to simplify medication regimen, ordering automatic refills and lack of knowledge for geriatric clinical pharmacology
What are the drugs associated with the most ADRs?
NSAIDs, diuretics, warfarin, ACEi, antidepressants, beta blockers, opiates, digoxin, prednisolone and clopidogrel
What are the most adverse events from?
Anticholinergics and sedatives
What are some common antimuscarinics from?
Dry mouth, dry eyes, constipation, reduced peristalsis, urinary retention and inability to compensate vision
Memory impairment, confusion and disorientation
How can absorption be affected?
Physiological changes occur that effect the rate but not generally the extent of absorption
May lead to a delay in onset of action
How can distribution be affected?
Body composition changes - reduced body mass, reduced body water and increased adipose tissue
Protein binding changes - decreased albumin
Increased permeability
How is metabolism affected?
Hepatic metabolism is affected by decreased liver mass and liver blood flow
Can lead to toxicity and reduced first pass metabolism
How is excretion affected?
Renal function decreases with age
Reduced clearance and increases half life of many drugs leading to toxicity
How is there increased sensitivity to particular medicines?
Change in receptor binding, receptor umber and altered translation of receptor initiated cellular response
Ex. diazepam increase sedation and warfarin increases anti-coagulation
What are some prescribing tools and guides?
Beers’ criteria - list of inappropriate drugs for older people
STOP-START criteria
NHS Scotland Polypharmacy Guidance
What are the 7 steps to appropriate polypharmacy?
Right medicine?
Unnecessary medicine
Effective medicine?
Harmful medicine
Sustainability
Agree and share medical plan
What matters?
What psychiatric medications can cause ADRs?
Sedatives - increased effects of benzodiazepines
Anti-psychotics - increased adverse effects of postural hypertension, stroke and confusion
Anti-depressants - less effective
Describe opioids for older patients
More sensitive to effects and lower does are needed
Pethidine and tramadol may be less useful
What are the increased adverse effects of NSAIDs in older patients?
Renal impairment and GI bleeding
Describe digoxin and older patients
Increased toxicity and lower doses needed
Describe diuretics and older patients
Decreased peak effect but reduced clearance - abnormal urea and electrolytes
Issues including continence and mobility
Swollen legs are an inappropriate indication
Describe anti-hypertensives and older patients
May be exaggerated effects on BP and HR
Issues with postural hypertension
ACEi might not be metabolised to their active form
Renal adverse effects
Describe warfarin and older patients
More sensitive to warfarin
Greater risks from warfarin - GI bleeding and falls
Describe antibiotics and older patients
Increased adverse effects - diarrhoea, C. diff infection, blood dyscrasias (blood conditions), delirium, seizures and renal impairment
