Pain Management Flashcards
2 major types of pain
- nociceptive
- neuropathic
Denifition of nociceptive pain
Normal pain processing that occurs when free nerve endings are activated by tissue damage or inflammation
4 processes of nociceptive pain
- transduction
- transmission
- perception
- modulation
Definition of neuropathic pain
Abnormal processing of stimuli from the PNS or CNS that serves no useful purpose
Types of pain assessment tools
- universal pain assessment tool
- pain rating scale
- visual analogue scale
Types of adjuvant pain medications
- TCAs
- Anticonvulsants
TCAs used in pain control
- amitryptyline
- Imipramine
Anticonvulsatns used in pain control
- carbamazepine
- valproic acid
- gabapentin
- pregabalin
MOA of paracetamol
Inhibitrs prostaglandin synthesis centrally
Cautions for paracetamol use
- overdose = liver failure (NAPQI = toxic)
- nephropathy with chronic use
- caution in renal and hepatic impairment
Classification of NSAIDs
- COX-1 selective
- Non-selective
- COX-2 selective
Contra-indications for NSAIDS
- hypersensitivity
- acute PUD
Cautions for NSAIDS
- renal and hepatic impairment
- dyspepsia
- cardiac failure
- hypertension
- bleeding disorders
- asthma
Features of selective COX-2 inhibitors
- less GI effects
- increased CVS risk
- needs to be taken with meals
Adverse effects of NSAIDS
- bronchoconstriction
- fluid retention
- nephropathy and ARF
- bleeding
- hypersensitivity
- dyspepsia and PUD
- hepatotoxicity
AE of opioids
- nausea
- sedation
- constipation
- respiratory depression
MOA of morphine
- affinity for u receptors
- histamine release
MOA of tramadol
- u receptor agonist
- inhibit seotonin and noradrenalin reuptake
Definition of chronic pain`
Pain lasting beyond the term of an injury or painful stimulus, present for more than 4-6 weeks
WHO pain relief ladder
- non-opioid
- weak opioids
- strong opioids
Cautions for morphine
- renal and hepatic impairment
- elderly
- pregnant
- lactation
- neonates
- decreased pulmonary reserve
Dose of morphine
10mg 4 hrly for 24 hours
Drug interactions with tramadol
- predisposes to serotonin syndrome when combined with SSRIs/ MAOIs
- metabolism induced by carbamazepine
Dose of tramadol
50mg 4-6 hrly, max 400mg/day
Dose of codeine
30-60mg 4-6 hrly
Describe variable metabolism of codeine
CYP2D6 variants
- slow metabolisers (poor analgesic effect, but constipation)
- rapid metabolisers (resp depression, coma and death)
Dose of amitryptyline
10-25mg nocte
