Opioids Flashcards
indications of opioids
- analgesia
- antitussive (ex: codeine)
opioid routes
PO, rectal, IM, IV, topical, subcut infusion, edpidural, intrathecal, intranasal, transmucosal
opioid MOA
bind opioid receptors in CNS to inhibit ascending pain pathways
what are the 3 main opioid receptors, and what do they all have in common?
- mu, delta, kappa
- all produce analgesia
- all have AEs of respiratory depression and slowed GI motility
tell me about the mu receptor
- euphoria
- AEs: bradycardia, emesis (vomiting), pruritus (itching)
- high potential for abuse/dependence
tell me about the delta receptor
- has a lower abuse potential
- no AEs unique to this receptor
tell me about the kappa receptor
- can produce spinal analgesia
- AEs: miosis (excessive pupil constriction), constipation, sedation, dysphoria
- has a lower abuse potential
common AEs of opioids (DNC)
- drowsiness
- nausea
- constipation
contraindications of opioids
- GI obstruction
- paralytic ileus (blocked intestine)
- respiratory depression
Boxed warnings for opioids include…
- increased levels with ethanol use
- addiction/abuse/misuse
- life-threatening respiratory depression
- severe AE with epidural or intrathecal admin
- neonatal opioid withdrawal syndrome
- death from accidental ingestion
- lethal medication errors
- life-threatening sedation/respiratory depression in combo with benzodiazepines or CNS depressants
what does the beers list say about opioids?
cautions against taking opioids in combo with 2+ CNS active meds; if history of falls or fracture
what are the strong mu agonists?
- morphine (MS Contin, Kadian)
- fentanyl (Actiq, Duragesic, Fentora, Sublimaze, Subsys)
- hydromorphone (Dilaudid, Exalgo)
- meperidine (Demerol)
- methadone
- oxycodone (Oxycontin; with acetaminophen: Percocet)
indications of strong mu agonists
severe pain
what should you watch out for with strong mu agonists?
- active metabolites
- morphine: can accumulate after extended dosing even if normal renal function
- meperdine: neurotoxic metabolite, especially if ↓ liver/renal function = anxiety, seizures
- hydromorphone: neuroexcitatory metabolite
- oxycodone: usually negligible levels of metabolite; often combined with acetaminophen or aspirin for additive effect
special considerations with fentanyl
- do NOT use for chronic pain management if opioid naive
- physical activity/heat on the patch can increase drug delivery in a negative way, causing OD or increasing AEs
- properly dispose of patch so it is out of reach of children and pets
what are the mild-moderate mu agonists (weak opioids)?
codeine and codeine combinations
indications of mild-mod mu agonists
moderate pain
tell me about codeine
- codeine is a prodrug, meaning it must be metabolized and converted to morphine in order to produce any effects; can get lingering metabolites
- codeine has antitussive effects, so it is used in cough syrup (abuse - purple drank, sizzurp)
tell me about partial mixed agonists
- Ex: buprenorphine (Suboxone)
- Agonist with high affinity mu receptor
- Lower analgesic efficacy than other opioids (lower Emax on dose-response curve)
- Antagonist at delta and kappa receptors
- Reduce withdrawal symptoms when tx opioid dependence
tell me about tramadol
- Weak mu and kappa agonist
- Inhibits reuptake of norepinephrine and serotonin (neurotransmitters in descending pain pathway)
- Less risk of dependence, but not impossible
- Risk of seizures, so avoid if hx or in combo w other drugs that can increase risk (antidepressants)
drugs used for neuropathic pain (4)
- duloxetine (Cymbalta)
- pregabalin (Lyrica)
- gabapentin (Neurontin)
- amitriptyline
duloxetine (Cymbalta)
I was tired and nauseous from my new antidepressants, and then my brother crashed his deluxe cymbals so loud it gave me a headache!
- Class: serotonin-norepinephrine reuptake inhibitor (SNRI), antidepressant
- AE: nausea, dry mouth, headache, dose-related fatigue and drowsiness
pregabalin (Lyrica)
Ever since pre-K, Lyrica has gained weight and is always tired. She got dizzy going down the slide at recess and started convulsing.
- Class: GABA analogs, anticonvulsant
- AE: dizziness, drowsiness, headache, fatigue, peripheral edema, weight gain
gabapentin (Neurontin) = more basic version of pregabalin
- Class: GABA analog, anticonvulsant
- AE: dizziness, drowsiness
- Common due to cost
amitriptyline
Am I trippin, or did riding a tricycle make me have to poop, pee, drink water, and use eye drops?
- Class: tricyclic antidepressant (TCA)
- AE: sedation, anticholinergic effects (blurred vision, dry mouth, urinary retention, constipation)
- Less common due to AE
types of cancer pain (3)
- bone pain (metastases; necrosis due to radiation)
- aching pain (compressed neural tissue)
- visceral pain (chemo, radiation-induced fibrosis, scar tissue from surgery)
treatment for mild cancer pain
- NSAIDs
- acetaminophen
- short-acting opioids
treatment for moderate cancer pain
short-acting opioids with titration
treatment for severe cancer pain
- strong opioids
- long-acting + immediate for breakthrough pain
naloxone (Narcan)
- opioid antagonist/reversal agent
- For acute opioid overdose or respiratory depression with therapeutic opioid doses
- Competitive antagonist at μ-, κ-, and δ-receptors
- Highest affinity for the μ-receptor = rapidly reversing respiratory depression and euphoria with less impact on analgesia
- IV, IM, subcut, intranasal
