Analgesic misuse Flashcards
what are some of the associations with those unregistered?
- lower SE background
- education
- alcohol and drug dependency
- severe mental health problems (the social drift effect)
- personal care takes lower priority
- dental anxiety/phobia
- homeless
- visiting/temporary residents/asylum seekers
name 5 analgesics
- asprin
- NSAIDs (ibuprofen/diclofenac)
- paracetamol
- paracetamol compound preperations
- opiates/opioids (codiene/dihydrocodiene/tramadol)
where is paracetamol absorbed and how well?
well absorbed in the small intestine
what is the peak plasma time for paracetamol?
60 mins
what is the half life for paracetamol?
2 hrs
what is the cyclo-oxygenase system?
it is an enzyme responsible for the production of prostanoids such as prostaglandins
what are prostaglandins?
a hormone like substance that participates in a variety of different bodily systems including the body’s response to damage/injury
is paracetamol more or less effective at inhibiting the cyclo-oxygenase system than conventional NSAIDs?
less effective than NSAIDs
how does paracetamol give analgesia?
it inhibits brain prostaglandin synthesis (PGE1 and PGE2)
paracetamol inhibits prostaglandin synthesis in the hypothalamus giving..?
anti-pyretic (anti-fever)
what are 3 possible side effects of paracetamol?
rash, white blood cell disorders, hepatotoxicity (destruction to the liver cells)
what can happen during paracetamol overdose?
hepatocellular necrosis
hepatocellular damage to can be reduced by giving what?
N-actyl cysteine supplement (NAC or Parvolex)
what is the issue with NAC in treating a paracetamol overdose?
it comes with risk of severe allergic reaction
how many phases of the paracetamol overdose are there?
4
how long are you in phase 1?
what are the signs and symptoms of phase 1 paracetamol overdose?
signs = pallor, malaise, vomiting, sweating symptoms = anorexia, nausea, vomiting
what are the signs and symptoms of phase 2 paracetamol overdose?
signs = tachycardia, hypotension symptoms = upper abdominal pain
when does phase 2 paracetamol overdose occur?
24-48 hrs
when does phase 3 paracetamol overdose occur?
3-4 days
what are the signs and symptoms of phase 3 paracetamol overdose?
jaundice, bleeding, encephalopathy (abnormal brain function)
when does stage 4 paracetamol overdose occur?
4-11 days
what is the signs of phase 4 paracetamol overdose?
recovery or death depending on damage severity
what type of paracetamol overdose has a higher mortality/morbidity effect?
staggered unintentional overdose more dangerous that intentional one bolus time despite lower doses
what is the normal toxic dose?
10g/24hrs or 150g/kg
what is the ‘at risk’ of a toxic dose?
7mg/24hrs or 75mg/kg
what are some of the additional risks for hepatotoxicity?
- undernourished/underweight (
what are the features of aspirin OD?
- increased respiratory rate
- ringing in ears
- parasthesia (pins and needles)
- vomiting/nausea
- drowsiness
what are the 5 main risks of aspirin OD?
- bleeding
- acidosis
- cerebral oedema
- coma
- death
what drug may cause a chemical burn to the mucosa?
if patient uses topical aspirin to relieve tooth ache
what are the initial features of NSAID OD?
- enhanced normal effects
- anti-platelet effects (bleeding and bruising)
- metabolic effects (dizziness, tinnitus, paraesthesia)
- GI irritation (epigastric pain, nausea, vomiting)
what are the eventual features of NSAID OD?
- renal impairment
- cerebral oedema
- cardiac arrest
what are the 3 main features of opiate OD?
- pupils constricted
- drowsiness but sometimes confusion and agitation
- reduced GCS (airway risk and respiratory depression)
what are some issues with prescribing opiates?
- dependence
- misuse
what can tramadol also cause in OD?
seizures and serotonin syndrome (respiratory depression not prominent with tramadol)
what are 3 resources for advice on a patient who may have overdosed?
TOXBASE (online database)
NPIS (national poisons information service
Local A+E (by phone first)
when to calculate patients weight in kg with suspected paracetamol OD?
if >4g in 24hrs
