Opioid analgesics Flashcards
What is an opiate?
drug derived from opium poppy
What is the persistent, compulsive continuation of a behavior or use of a chemical substance despite its adverse effects?
addiction
What is a decreased drug response to a drug w/ continued administration that can be overcome with increasing the dose?
drug tolerance
What is the continued need of a user to take a drug?
drug dependence
What’s the class of natural endogenous peptides that bind to human mu delta, and kappa opiod receptors?
endogenous opioid peptides
How much do chronic pain syndromes cost the country?
65-70bill annually
What’s the difference between acute and chronic pain?
acute is related to an event and resolves and not requiring long term medication, while chronic is not always identified and includes multiple types of pain, prolonged durations
What type of pain has direct simulation, transmission along normal nerves, with tissue injury apparent, and source is from somatic or visceral stimulants?
nociceptive
What type of pain is caused by disordered peripheral or central nerves which can exceed observable injury and can be described as burning, tingling, shooting, stabbing, or electrical?
neuropathic
What is the function of the mu opioid receptor subtype?
supraspinal and spinal analgesia, sedation, inhibition of respiration, slowed GI transit, modulation of hormone and neurotransmitter release
What is the function of the delta receptor subtype?
supraspinal and spinal analgesia, development of tolerance
What is the function of the kappa receptor subtype?
supraspinal and spinal analgesia, sedative actions, slowed GI tract
How do opiods act?
by binding to the receptors, modifies sensory to pain
What are the advantages of opiods?
multiple routes of administration, ease of titration, reliable, effective
What are some opioid agonists?
codeine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone
What are some weak agonists/reuptake inhibitors?
tapentadol and tramadol
What are some weak agonist-antagonists?
buprenorphine
What are some antagonists?
naloxone, naltrexone, methylnaltrexone, naloxegol
What’s the opioid MOA?
close channels on PREsynaptic nerve and inhibit POSTsynpatic inhibing transmission of signal
What opioids are metabolized by cytochrome CYP2D6 to active metabolites?
Codeine –> morphine
oxycodone –> oxymorphone
hydrocodone -> hydromorphone
What route is preferred?
oral, but can take 45 minutes, with IV reserved for severe pain
How do most opioid agonists metabolize?
hepatically with eliminaton by kidneys
How is morphine different?
undergoes glucuronidation to metabolite similar
What are opioid agonist ADRs?
drowsiness and sedation, N/V with ambulation, cough suppressant/CO2 levels rise, pupillary constriction (except meperidine)
pinpoint pupils, constipation, urinary retention, flushing, pruritus, diaphoresis
How is mereperidine different?
can cause tachycardia instead of bradychardia and can have high histamine release
histamine release
natural>semi-synthetic>synthetic
merpiridine, codeine, morphine > hydrocodone, oxycodone > hydromorphone, fetanyl
The more ____ the opioid, the ___ histamine release
potent, less
How can you manage opioid ADRs?
bowel regimen, decrease dose, take w/ food, antihistamine or consider other drugs
How can you manage mood changes?
decrease dose, consider longer acting
How do you manage urinary retention?
catheter, more non-opioids
What class cannot be refilled
class 2
What class can only be refilled with a 6 month limit?
3
What do you counsel the patient with?
can cause drowsiness, do not operate machinery, night vision may be affected, do not share, do not chew or crush
avoid alcohol and caution w/ CNS depressants, and prescribe laxatives like bisacodyl/docusate and PEG
What signifies an allergic reaction to an opioid?
difficulty breathing, severe drop in BP, rash, swelling, use agent in different class
If you have an allergy to morphine, codeine, hydrocodone, hydromorphone, or oxycodone, what do you use?
fetanyl, meperidine, methadone, tramadol, or tapentadol
What are examples of group 1 opiates?
morphine, codeine, thebaine, natural, group 1
What are examples of semi-synthetics?
hydrocodone, oxycodone, hydromorphone, oxymorphone, buprenorphine, group 2
What are examples of synthetics?
fetanyl, methadone, tramadol, propoxyphene, meperidine, group 3 and CAN be used with an allergy to others
What are some strong opioids?
morhpine, hydromorphone (dialudid), meperidine (demerol), fentanyl, methadone
What are some moderate opioid agonists?
oxycodone (oxycontin, percodan, percocet), hydrocodone (lortab, norco, vicodin, vicoprofen), codeine (tylenol w/ codeine)
When should you avoid morphine?
renal dysfunction
How is codeine usually prescribed?
in combo with APAP or promethazine (antitussive)
CYP2D6 = ultra–rapid metabolizers
avoid in peds
When should you use caution with hydrocodone?
with APAP products
When should you avoid using oxycodone?
with CYP3A4 inhibitors
When should you use caution using hydromorphine?
with CYP3A4 (use low doses) and very potent!
How is fetanyl used?
only for chronic pain and can be a patch, IV, lollipop, and also caution with CYP3A4 inhibitors
How is meperidine (demerol_ used?
sometimes for shivering post-op, can increase risk of serotonin syndrome, AVOID using as an analgesic, and can accumulate with renal failure and cause CNS toxicity
How is methadone used?
treatment of patients addicted to narcotics, Wide variability in half life, risk of QT prolongation, with MANY drug interactions
What opioids should you avoid in hepatic impairment?
codeine, meperidine
What opioids should you use with caution in hepatic impairment?
oxycodone, hydrocodone, morphine, fetanyl
What opioids should you avoid in renal impairment?
morphine, codeine, meperidine, tramadol
all others use cautiously
What’s tramadols moa?
agonist/reuptake inhib, weak mu agonist, serotonin/nore reuptake inhibitor
what are ADRs of tramadol?
lowers seizure threshold and serotonin syndrome, nausea
When can you not use tramadol?
mao-i use within 14 days, Hx of epilepsy
What is the MOA of tapentadol?
agonist/reuptake inhib, moderate mu agonist, strong NE reuptake inhibitor, weak 5-HT inhibitor
What are ADRS of tapentadol?
seizures and serotonin syndrome
Is tapentadol effective?
as effective as oxycodone with lower GI effects
What’s the MOA of buprenorphine?
mixed agonist-antagonist, partial Mu agonist, kappa antagonist, for moderate pain or opioid use abuse
Is buprenorphine oral bioavailable?
no, need to give sublingually
Why is naloxone added to buprenorphine?
to prevent abuse, Suboxone
What are signs/symptoms of opioid overdose?
somnolence/difficulty to arouse, respiratory depression, cold/clammy skin, constricted pupils
What are warnings w/ naloxone?
will cause withdrawal and repeat doses may be needed
Does methylnaltrexone and naloxegol have an effect on analgesia and enter CNS?
no
What can methylnaltrexone and naloxegol cause?
severe diarrhea, GI perf do not use with GI obstruction and strong 3A4 inhibitors (naloxegol)
What can you switch a patient to for less itching?
hydromorphone and fetanyl are lowest
