Analgesia Flashcards
Give ways in which analgesics may reduce nociception
Acting at site of injury
Blocking nerve conduction
Suppressing nociceptive signals in dorsal horn
Activating inhibitory controls
Opioid action is mediated by which receptors?
G protein-coupled opioid receptors
What are the classes of opioid receptors?
Mu
Delta
Kappa
Which of the opioid receptors are responsible for most the opioid analgesic action?
Mu
What is the main respiratory side effect of opioids?
Apnoea
What is the main cardiovascular side effect of opioids?
Orthostatic hypotension
Give some GI side effects of opioids
N + V
Constipation
Give some CNS side effects of opioids
Confusion
Euphoria
Hallucinations
Dizziness
When is heroin used to control pain?
Severe post-operative pain
Why is codeine useless in some patients?
As they lack the enzymes to convert it to morphine
Fentanyl is suitable for acute/chronic pain states
Chronic
When is pethidine mainly used?
Labour pains in childbirth
Which drug is used to antagonise mu receptors and reverse opioid toxicity?
Naloxone
How do NSAIDs work?
They inhibit COX enzymes to prevent synthesis of prostaglandins
Give examples of drugs that can be used for neuropathic pain
Gabapentin/pregabalin
Amitryptiline (TCA)
Carbamazepine