Pain Flashcards
Drug Class Used to Reverse the Effects of Opioids
Opioid Antagonists
Drug Classes for Treating Pain
Opioid Analgesics
Non-Opioid Analgesics
Anti-migraine Agents
Opioid Receptors
Mu Kappa Sigma Delta Epsilon
Opioid (narcotic) Analgesics
Used to relieve moderate to severe pain
Some used for anaesthesia
Morphine
An opioid analgesic and agonist
Interacts with mu and kappa receptors
Primarily used as an alagesiac and anaesthesia
Adverse effects include respiratory depression, sedation, nausea, and vomiting and dysphoria(restlessness, depression, anxiety)
Monitoring Opioid Therapy
Assess potential for opioid dependancy
Have narcotic antagonists available to reverse negative effects
Assist clients with activity as they may be quite disoriented.
Monitor urine output for retention
Monitor bowel habits for constipation
An initial assessment should screen for severe respiratory disorders, increased inter cranial pressure, seizures, and liver/renal disease
Treatment for Opioid Dependance
Physical dependancy lasts 7 days
Psychological dependance can last many months or years
Often clients switch from IV and inhaled forms to oral form called Methadone
Methadone does not cure addiction but avoids withdrawal symptoms and does not have the euphoric effect
Opioid Antagonists
Used to reverse effects of opioids
Used for overdoses or in cases of overly aggressive pain therapy
Naloxone (Narcan) and Naltrexone (ReVia)
Naloxone (Narcan)
Opioid Antagonist
Used to reverse opioid effects
Mechanism of action is the blocking of mu and kappa receptors
Minimal toxicity, however adverse effects or reversing analgesia of increases BP, tremors, hyperventilation, nausea/vomiting, and drowsiness
Employed when
Acute vs Chronic
Acute is intense pain occurring over a defined time, usually less than 6 months
Chronic pain lasts longer than 6 months and interferes with daily activities. Chronic pain is associated with feelings of hopelessness
Nociceptor vs Neuropathic
Nociceptor is a pain whose source is due to tissue injury. It can be somatic (sharp and localized) or visceral (dull, throbbing, aching)
Neuropathic pain is due to injury of the nerves and is a burning, shooting or numbing pain.
Nociceptor pain responds well to conventional pain-relief drugs while neuropathic pain often has less therapeutic success
Opioids
Act on CNS
Exert action by interacting with receptors, the most important of which are mu and kappa.
Agonists stimulate the receptors while antagonists block it.
Drugs of choice for moderate to severe pain
Mu receptor
Opioid receptor
Analgesia, decreases GI motility, respiration depression, sedation and physical dependance
Kappa receptor
Opioid receptor
Analgesia, decreased GI motility, sedation
NSAID
Nonsteroidal Anti-Inflammatory Drug
Act by inhibiting pain mediators at nociceptor level
Inhibit cyclooxygenase(COX) an enzyme responsible for formation of prostaglandins.
Inhibition of COX results in reduced pain and inflammation
Prostaglandins
Formed with help of two other enzymes called cyclooxygenase type 1 and 2
COX-2 is more specific for synthesis of prostaglandins that cause pain/inflammation
Aspirin blocks both, while Celebrex is an example of a COX-2 selective inhibitor
Acetaminophen
Nonopioid analgesic
Aspirin
NSAID, Salicylate
Inhibits prostaglandin synthesis
Primary uses are as an analgesic, anticoagulant, antipyretic, antiinflammitory
Adverse Effects include gastric discomfort, increased bleeding time
Narcan (naloxone)
Opioid Antagonist
Blocks mu and kappa receptors
Used primarily to reverse opioid effects including respiratory depression
Minimal toxicity however, it will cause immediate withdrawals in those with physical dependancy: increased BP, tremors, hyperventilation, nausea/vomiting, and drowsiness
Goals of Migraine Therapy
1) stop migraines in progress
2) prevent migraines from occurring
Drugs for Treating Migraines
Ergotamine alkaloids
Triptans
Drugs for Preventing Migraines
Beta-Adrenergic Blockers
Calcium Channel Blockers
Tricyclics Antidepressants
Sumatriptan (Imitrex)
Triptan used to treat migraines in progress.
Vasoconstriction of the cranial arteries is a result 5-HT serotonin receptor stimulation
Side effects include dizziness, drowsiness and warming sensations
Interacts with other medications
Triptans
Stimulate serotonin receptor 5-HT subtype
Cause vasoconstriction in certain blood vessels and relieves migraine pain
Ergot Alkaloids
Interact with adrenergic, dopaminergic and serotonin receptors
Promotes vasoconstriction and stops migraines
