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Background, Goal and Objectives Polypharmacy PDF
Polypharmacy - weighing up the benefits and harms
Elderly people are at increased risk of drug related problems
Drugs associated with increased risk of adverse drug reactions in elderly people
Common drug interactions in elderly people
Recognising adverse drug reactions
Risk factors for drug related problems in elderly people
A really good recipe for DRP
Drug related harm; terms and definitions
Hospital admissions for adverse drug reactions
Commonly reported adverse drug reactions
References, Bibliography

Common drug interactions in elderly people

It is impossible to remember all possible drug interactions; see how long the list is in appendix one of the BNF! A number of drug combinations are frequently used but have the potential to cause significant harm if not managed appropriately. Not every elderly adult who takes these medications together will experience an adverse reaction.

Common Drug Interactions
Drug combination Risk of harm Prevention
warfarin / NSAIDs increased risk of bleeding review need for NSAID consider paracetamol as an alternative
warfarin / amiodarone monitor INR and adjust warfarin dose accordingly
warfarin / sulfa drugs use alternative antibiotic
warfarin / macrolides
warfarin / norfloxacin
warfarin / phenytoin increased or possible decreased effects of warfarin
phenytoin concentration possibly increased
monitor phenytoin level and INR
ACE inhibitors / K+ supplements elevated potassium levels monitor potassium levels discontinue K+ supplement if not needed
ACE inhibitors / spironolactone elevated potassium levels
renal failure
monitor potassium levels and renal function
ACE inhibitors / NSAIDs renal failure re-evaluate need for NSAID monitor renal function avoid hypovolaemia
digoxin / amiodarone digoxin toxicity decrease dose of digoxin by 50% when adding amiodarone and check digoxin levels weekly until stable
digoxin / verapamil digoxin toxicity
bradycardia, heart block
check ECG
re-evaluate need for these drugs
theophylline / norfloxacin and ciprofloxacin theophylline toxicity re-evaluate need for these drugs
monitor theophylline levels
anticholinergic combinations e.g. TCA, sedating antihistamine, antipsychotic, oxybutynin, orphenadrine, benztropine, etc sedation, confusion, blurred vision, falls reduce numbers, strength or doses of these drugs
drugs acting on the CNS
combinations of antiepileptics, antipsychotics, analgesics, antidepressants, etc
sedation, confusion, falls reduce numbers, strength or doses of these drugs

“The ingenuity of man has ever been fond of exerting itself to varied forms and combinations of medicines.”
William Withering, 1785

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