Opioids Flashcards
rx length
Up to 3 days for most things; up to 7d max
MOA
Most bind to and stimulate the Mu opioid receptors (agonists). Inhibit neurotransmitter (substance P, glutamate, CGRP) release AND reduce transmission of pain signals. Hyperpolarise postysynaptic cell, so less likely to generate any further pain sensations. Raise the pain threshold at the spinal cord level (dorsal horn). Alter the brain’s perception of pain. The stronger the agonist, the greater the effect
opioid contras
Use in Head Injuries (can increase intracranial pressure), Use in Pregnancy (stick to short term use), Impaired Pulmonary Function, Impaired Hepatic or Renal Function, Endocrine Disease, Undiagnosed abdominal pain
AEs
nausea, constipation, respiratory depression. flushing, pruritis, hypotension from release of histamine. Pinpoint pupils that do not respond to light.
overdose symptoms and treatment
Overdose: CNS depression (coma), resp depression (apnea or bradypnea), miosis. Give Narcan (opioid receptor antagonist) IV, IN, IM, or SC, onset in 2-3 min and give 2nd dose at 3 min if still not awake; effect lasts 2 hrs, so pts should be monitored for 4-6 hrs after Narcan; induces opioid withdrawal (agitation, anxiety, confusion, tachycardia, HTN.
interactions
“Sedative-Hypnotics: Benzodiazepines, Diphenhydramine, Soma, tramadol
Alcohol
Antipsychotics
MOAIs”
pt counseling - 4
“PO initial onset in 20 min, full benefit at 1hr.
take antinausea 20 min before
Let pt know when using combo w/ acetaminophen - caution against taking too much aceta otherwise
Avoid alcohol. don’t take benzodiazepines or diphenhydramine at same time; space out 2-4 hrs if you really need it due to extra sedative effect”
co-prescribe
Co-prescribe antiemetic (Zofran) and senna + bisacodyl; also naloxone if risk factors (prior OD, substance abuse, doses >120MME/d, concomitant benzo)
weakest agonist
codeine
codeine contras
Absolute: <12 y/o, <18 y/o after tonsillectomy / adenoidectomy. Avoid in <18 y/o
most constipating opioid
codeine
MOA: mild-mod agonist. Targets the mu-receptor and inhibits reuptake serotonin and norepinephrine
tramadol
tramadol contras
Caution in pts w/ seizure hz or those on TCAs or serotonergic agents
which opioids are only partially antagonised by naloxone
tramadol, Tapentadol (Nucynta)
tramadol dose adjustment for whom?
CrCl <30 or severe hepatic impairment, dose Q12 hours
indications: “ped surgery/ED
extended release: neuropathic pain”
Tapentadol (Nucynta) PO, IV