Pain management medications Flashcards
Pain:
- compassion and empathy are an important part of pain care
- pain triggers fear and anxiety and can delay the healing process
- narcotics are often underused due to the fear of addiction
- post-operatively the narcotic dose is titrated against the degree of pain and is a short-term use
Classification of pain:
Productive pain:
- occurs immediately after tissue damage
- warning pain - self-protection e.g. removing hand from hot iron
Nonproductive pain:
- often caused by tissue injury, having minimal control over it
- stomach ulcer
- perforated appendix
Visceral pain:
- emanates from internal organs and voluntary tissue of the torso
- non narcotics have little effect on this type of pain
Musculoskeletal/somatic pain
- responds well to non-narcotics
Classification of pain 2:
Neuropathic pain:
- pain that originated in the nervous system\
- requires treatment with drugs
- responds to anticonvulsants
Acute pain:
- characterised by a sudden onset and transient duration
- site of pain is easily identifies
- normal self-limit or readily corrected
Chronic pain:
- greater than 6-months duration
- variable response pattern
- difficult to evaluate the pain
- treatment rarely offers complete relief
- suffering tends to increase over time
Transmisson of pain:
- transmisson of pain impulses from the pain receptors to the central nervous system
Pain assessment:
- pain is different for every individual, subjective and a complex experience
- pain is influenced by culture, prognosis, diagnosis, coping strategies, values, fear and anxiety
- vital signs should be assessed regularly
- pain assessment should occur frequently
- assessment should be during movement and activity and at rest
- effects of analgesics on the experience of pain should be assessed
- pain history and self-reports
Narcotic analgesics:
- suppress the perception of pain by binding to opiate receptors sites in the PNS and CNS
- mimic effect of endorphins
- are opioid agonists, stimulating opioid receptors in the brain
Opioids:
- all narcotics originally derived from the opium poppy
- morphine is the main compound
- morphine remains the most effective agent for treating pain, cough and diarrhoea
Common opioid medications:
- Morphine
- Codeine
- Methadone
-Tramadol - Oxycodone
- Fentanyl
- Oxycontin
- Remifentanil
Adverse effects of narcotics:
- tolerance is to euphoric and analgesic properties develops quickly
- depression and overdose potential
Morphine:
- Most common opioid use
- short half-life of 4 hours
- frequent dosing required
- available in slow-release form - not suitable for acute pain
- eliminated via liver
Codeine:
- partially converted into morphine by liver
- useful for moderate pain
- minimal euphoric effect
Methadone:
- substitute for abused narcotics
- fewer withdrawal side effects due to 24-hour half-life
- addiction may be more powerful
- binds strongly to opioid receptors, reducing effect of injected opiates
Tramadol:
- rarely produces euphoria, tolerance or addiction
- useful for moderate to severe pain
- short half-life of 3 hours
- effective for many types of pain except neurogenic pain
- side effects - nausea, lower respiratory rate, depression
Oxycodone:
- longer half-life and less hepatic first pass than morphine
- lower abuse potential
- onset of action 1 hour - duration of 12 hours
- should not be used for acute pain
- used for overnight analgesia - suppository
Fentanyl:
- used for short medical and surgical procedures and pain relief of cancer
- not used postoperatively or for acute pain - risk of depression
- useful for chronic pain
- transdermal patch - 3/7 duration
- date and remove after 72 hours
- apply new patch to new location
- less likely to cause constipation
