BRAINS and AIMS Flashcards
BRAINS AIMS
-what does this stand for
Benefits Risks Adverse effects Interactions Necessary prophylaxis Susceptible groups
Administering
Informing
Monitoring
Stopping
What are the risks involved in drug prescribing
Overdosing
Contraindications
Costs
Resistance to medication
How to deal with adverse reactions
Is it time or dose dependent What drug is responsible How would you correct the ADR Stop ADR Report
What is a dose dependent adverse reaction
-what are the 3 types
Adverse reaction that is dependent on the amount of drug given
Supratherapeutic - toxic -paracetamol OD Therapeutic - side effects -NSAID renal failure -ACEi cough Subtherapeutic - Hypersusceptible -allergy
What are the dose dependent drugs that cause hepatitis
How would you recognise this?
Increase in ALT
Azathiopurine
Paracetamol
What are the dose independent drugs that cause hepatitis
How would you recognise this
Increase in ALT Isoniazide, Pyrazinamide Valproate Methyldopa Statins NSAIDS Phenytoin
What are the dose dependent drugs that cause cholestasis
How would you recognise this
Increase in AST and bilirubin
Rifampicin
Estrogen+Anabolic steroids
What are the dose independent drugs that cause cholestasis
How would you remember this
How would you recognise this
Increase in AST and bilirubin - Cl/Chl
Chlorpromazine - antipsychotic
Clarythromycin - ABx
Clavulanate-amox
Cloxacilin (flu)
Cimetidine - SSRI
Carbimazole - antithyroid
Chlorpropamide - sulphonylurea
What are the drugs that cause microvesicular steatosis
How would you remember this
VAT
Valproate
Aspirin
Tetracyclines
What are the drugs that cause macrovesicular steatosis
How would you remember this
Fatty liver, cirrhosis
AMA
Alcoholic hepatitis
Methotrexate
Amiodarone
What are time dependent ADRs
- rapid
- first dose
- risk increases at first then decreaess
- risk increases with time
- withdrawal
- delayed
What are examples of each one
How would you manage each type
Rapid - administer slowly
-IV vancomycin => Red man syndrome (systemic histamine release)
First dose - careful monitoring
- ACEi => hypotension
- penicilin => allergy
Risk increases at first then diminishes - warn patients of possible ADRs
-carbimazole, 5ASA (-salazines) => agranulocytosis (sore throat, increased bleeding risk, anemia)
Late - warn, monitor, prophylaxis if possible
-CS => osteoporosis
Withdrawal - warn, replace with longer acting drug if withdrawal not possible
-opiates, BZ, methyldopa(HTN), Bb => withdrawal symptoms
Delayed - avoid, screen, warn
-ciclosporin => carcinogen
What are the time independent ADRs
- due to change in dose
- due to change on concentration
- due to neither
What are examples of each one
How would you manage each type
Change in dose from changed formulations
-stick to 1 brand for a patient
Change in concentration
-warn, monitor, reduce dosage, avoid interacting drugs
Due to neither
-warn, monitor, avoid interacting drugs
What are common examples of drugs that affect PO absorption
- decrease GI motility
- increase GI motility
Decrease GI motility
- opiates
- TCA
Increase GI motility
-metoclopromide (antiemetic)
Alter rate of absorption of other drugs
Describe the significance of displacement
-possible outcomes
Displaced drug => metabolised and excreted
Displaced from plasma proteins => increased toxicity, potency
- ASA+NSAIDs => methotrexate toxicity if secretion impaired
- ASA+NSAID+warfarin => increase bleeding risk
What are the methods of excretion
Glomerular filtration of unbound drug
Active tubular secretion
-ability reduced in renal failure
Passive tubular reabsorption
What are liver enzyme inducers
What do they do?
What are the drugs that do this
How would you remember this
Increase activity of liver enzymes
=> active drug broken down so less potent
=> inactive drug activated so more potent
PCBRAS Phenytoin (antiepileptic) Carbamazepine Barbiturates, BBQ foods Rifampicin Alcohol (chronic) St Johns Wort
What are liver enzyme inhibitors
What do they do
What are the drugs that do this
How would you remember this
Decrease activity of liver enzymes
=> active drug not broken down
=> inactive drug not activated
GODEVICES Grapefruit juice Omeprazole Disulfriam Erythromycin Valproate, Isoniazid Cimetidine, Ethanol (acute) Sulphonamides,
Allopurinol Metronidazole, ketoconazole Ciprofloxacin Verapamil, diltaizam, amiodarone Chloramphenicol SSRIs
What are the clinically significant drugs with a narrow therapeutic range
How would you remember this
Small range where the drug concentration is safe and toxic
WAC STOPS Warfarin Antiarrythmics Ciclosporin Sulphonylureas Theophyllines Oral Contraceptives Phenytoin Steroids, statins
Describe the interaction between SSRIs and liver enzymes
What is the danger when prescribing SSRIs and opioid pain relief
SSRIs (eg, fluoxetine, paroxetine) inhibit CYP2D6
Many opioids need to be activated by CYP2D6 => less effective if inhibited
Tramadol also has SNRI properties => increased risk of seretonin syndrome if coadministered with SSRIs
What are the common interactions with warfarin
Protein binding displacement
-NSAIDs
Inhibit metabolism
-amiodarone, metronidazole, acute alcohol
Induction of liver metabolism
- phenytoin
- carbimazepine
- barbiturates, BBQ
- Rifampicin
- Alcohol
- St Johns Wort
Cranberry juice => increased INR
Necassery prophylaxis for
- NSAIDs
- opioids
- CS
NSAIDs => PPI (lansoprazole)
Opioids => laxatives, antiemetics
CS - if 3months, 7.5mg+ => alendronate
Susceptibility mnemonic
-ASADGAP
Allergy Sex Age Disease Genetic Altered physiology Pregnancy, breast feeding
What are women and men more susceptible to?
How would you reduce this risk
Use lower doses
Women
- alcohol
- ACEi cough
- drug induced lupus
- hepatitis - methyldopa
- cholestasis - flucloxacilin
Men
-cholestasis - coamox
What common drugs are older adults more susceptible to
How would you reduce this risk
Lower doses, monitor carefully but avoid where possible
Diuretics, antiHTN, Bb Digoxin NSAIDs CNS drugs (BZ) TCA H1 antihistamines (chlorpheniramine) H2 antagonists (ranitidine) Opiates
Describe how renal impairment may affect drugs
How would you approach this
Accummulation of renally cleared drugs
- avoid drugs/reduced dose with narrow therapeutic range
- increased nephrotoxicity of NSAIDs
Describe how hepatic impairment may affect drugs
What drugs would this affect
CAFE METRO - altered PK, PD
Clotting reduced - warfarin, aspirin, NSAID
Albumin reduced - phenytoin, prednisolone toxicity
Fluid retention
Electrolyte imbalance - NSAIDs, steroids, furosemide
Metabolism reduced - opioids not activated or broken down
Encephalopathy - sedatives, hypoK (diuretics), opioids, constipators
Toxic liver drugs - NSAIDs => hepatitis, cholestasis, steatosis
Renal function impacted - NSAIDs
Altered physiology susceptibility
- pregnancy
- drugs to avoid
Increased renal clearance of
-lithium, digoxin, penicillins => need to increase dose
Risk to fetus
- thalidomide
- phenytoin, valproate
- warfarin, lithium
- retinoids
