Opioid analgesics Flashcards
What drugs can be used in pain treatment? (3)
I. Opioid analgesics
II. Analgesics and NSAIDs
III. Specific analgesics (adjuvants)
Mechanism of action for opiod analgesics, opioids or narcotics?
-specific CNS receptors (opiates or opioids receptors changing perception of pain)
What is the effect of opiod analgesics, opioids or narcotics? (6)
- produce analgesia (Strong)
- sedation
- somnolence (sleepyness)
- tolerance
- addiction
- abstinence
What is somnolence?
sleepyness
Mechanism of action for non-opioid analgesics (NSAIDS + Analgesics)? (2)
- Cox inhibitors
- inhibit prostaglandin synthesis (vasodialator
What is protaglandin? (2)
a vasodilator.
Needs the COX enzyme
What is the effect of non-opioid analgesics (NSAIDS + Analgesics)?
- analgesia (moderate)
- antipyretic
- nonaddictive
SOME:
- anti-inflammatory
- antiplatlet
What are the adjuvant analgesic drug types? (3)
- anti-epileptic
- anti-depressants
- neuroleptics
What do you prescribe in the first step of pain management? (3)
- Mild to moderate pain
- NSAIDs (ibuprofen…)
- paracetamol
What do you prescribe in the 2nd step of pain management? (3)
- Moderate to intense pain
- NSAIDs + Weak opioids (tramadol, codeine)
What do you prescribe in the 3rd step of pain management? (2)
- Intense pain uncontrolled with previous drugs
- Strong opioid (morphine)
What do you prescribe in the 4th step of pain management? (3)
-Very intense pain
Invasive analgesic actions:
- intrathecal or epidural morphine
- infiltrations of local anesthetics
In which step of pain management do you add adjuvant drugs?
-can be added in all steps depending on the pain
What kind of pain do opioid analgesics treat? (2)
- moderate to severe
- acute or chronic
What kind of analgesic effect do opioid analgesics have?
intense
Opioid analgesics have an affinity for ______ receptors
opioid
NSAID indications? (3)
- headache
- arthralgia (joint pain)
- myalgia (muscle pain)
What is arthralgia?
joint pain
What is myalgia?
pain in a muscle or muscle group
Opioid indications?
- visceral pain
- intense pain
NSAID pain effectiveness?
moderate
opioids pain effectiveness?
intense
NSAID analgesic location?
peripheral
Opioid analgesic location?
central
Opioids are also called…. (2)
opiates & narcotics
Opioids come from…
Juice of the poppy (Papaver somniferum)
The poppy’s latin name is
Papaver somniferum
The most significant natural alkaloid obtained from opium is
morphine
Which drug is used as a reference or standard to compare with the rest of the opioids?
morphine
First preparation that demonstrated analgesic, sedative and euphoric properties was?
- Juice of the poppy (Papaver somniferum)
- 1st “opioid”
Opiate vs opioid?
- Opiate: products obtained from poppy juice and derivatives
- Opioid: any substance endogenous or exogenous with affinity for the
specific receptors.
What are the opioid receptors? (4)
- μ
- δ
- κ
- ORL-1
What is the mechanism of action for opioid receptors?
- affinity to opioid receptors
- DECREASE painful sensation
- DECREASE affective component of pain
What endogenous substances stimulate opioid receptors?
- beta-endorphins
- enkephalins
Location of opioid receptors? (5)
- C.N.S. : medulla, midbrain, thalamus, cortex
- PERIPHERAL N.S.
How do opioid analgesics work?
- act on receptors mu (μ),
What is the action of the mu (μ) receptors
- analgesic effect
- respiratory depression
What are the different types of opioids?
- major opioids
- minor opiates
- partial agonists
- agonist-antagonists
What are the major opioids? (4)
- MORPHINE
- FENTANYL
- PETHIDINE (meperidine)
- METADONE
What are the minor opiates? (3)
- CODEINE / DIDYDROCODEINE
- TRAMADOL
- DEXTROPOPOXYPHENE
What are the opioid antagonists?
- Naloxone
- Naltrexone
What is the opioid partial agonist?
Buprenorphinie
What is the opioid agonist-antagonist?
Pentazocine
Opioid route of administration? (3)
- oral
- sublingual (buprenorphine)
- Transdermal (buprenorphine, fentanyl)
- Parentreral (IM, IV, SC, epidural)
Why are opioids used orally?
good absorption
Opioid bioavailability orally? (2)
- low
- high hepatic first pass
Which opioids are used sublingually? why? (2)
- buprenorphine
- avoids hepatic first pass
Which opioids are used transdermally? why? (3)
- buprenorphine
- fentanyl
- avoids hepatic first pass
Describe opioid biotransformation and excretion
- elevated hepatic biotransformation
- renal excretion
Do opioids cross placenta and BBB?
yes
Opioid half life?
4-6 hrs
* can have controlled release preparations
define stupor
a state of near-unconsciousness or insensibility.
Pharmacologic actions of morphine
- Decreased level of consciousness: sedation and stupor
- Respiratory depression (dose + route dependent)
- hypothermia
- miosis (pupillary constriction)
- nausea + vomitting
- incr. muscle tone (high doses)
Morphine: acute or chronic?
both
depends on dose
What are the cardiovascular effects of morphine? (3)
- hypotension
- bradycardia (slow heart action)
- Vasodilation (decreasing vascular tone)
What are the GI effects of morphine? (4)
- delayed gastric emptying
- constipation
- increased pressure in bile ducts (hypertonic sphincter of oddi)
What are the urinary effects of morphine?
- increased bladder tone
- less urination (?)
Morphine and tolerance? (4)
- quick development of tolerance
- duration of action shortened
- response intensity decreases
- dose increase required
Morphine and dependence? (2)
- withdrawl =severe central and vegetative symptoms
- mostly sympathetic
Morphine withdrawal is mostly _______
sympathetic
ANALGESIC DOSE _______ ALTER THE LEVEL OF CONCIOUSNESS
does not
Morphine analgesic indications (4)
-reduces emotional response to pain
IV-SC for a few days:
- surgical interventions
- polytrauma
IV few days or SC (oral) chronic:
-tumors
When do you use subcutaneous or oral morphine?
chronic treatment of tumors
How/why do we use morphine for surgical interventions? (3)
analgesic
IV or SC for a few days
How/why do we use morphine for polytrauma? (3)
analgesic
IV or SC for a few days
How/why do we use morphine for tumors? (3)
analgesic
- IV few days or
- SC (oral) for chronic
What are the morphine vasodilator indications? (2)
- Acute pulmonary edema (iv-sc) (heart failure)
- Acute myocardial infarction (AMI)
How / why do we use morphine for Acute pulmonary edema? (3)
- vasodilator for heart failure
- IV or SC
Why do we use morphine for acute myocardial infarction?
vasodilator
What are the morphine sedative indications?
Mechanical ventilation (i.v-s.c..)
How / why do we use morphine for Mechanical ventilation?
- sedative
- IV or SC
Describe morphine respiratory depression (3)
- adverse effect
- can be used to relief respiratory effort in terminal situations
- maximum IV
- minimum oral
Morphine adverse effects (4)
- dry mouth (dental caries, periodontal disease, oropharyngeal candidiasis)
- allergic skin reactions (rare)
- tolerance to more depressant actions
- acute poisoning (coma respiratory depression, pinpoint pupils)
How does morphine act on the bronchus?
bronchoconstriction
Antidote for acute morphine poisoning?
naloxone
Morphine contraindications (8)
-respiratory failure
-billiary pancreatic colic pain (ONLY use
meperdine - anticholinergic effect)
-liver failure
-inferior myocardial infarction (incr. vagal tone, better meperidine)
-childbirth (risk of fetal respiratory depression)
-pregnancy (fetal abstinence syndrome)
-breastfeeding
-elderly
What drug is the exception for opioid contradiction for Biliary pancreatic colic pain
MEPERIDINE = PETHIDINE
What is the sphincter of Oddi?
-controls flow of bile and pancreatic juice into the second part of duodenum
Morphine has drug interactions with… (6)
- CNS depressants (incr.)
- Diuretics (decr.)
- Tricyclic antidepressants (incr. analgesic)
- CA-antagonists (incr. analgesic)
- rifampicin (incr. metabolism)
- delayed absorption of other drugs
Morphine interaction with CNS depressants causes….? Which drugs? (5)
- (opiates) increased effect
- neuroleptics
- antidepressants
- benzodiazepines
- ethanol
Morphine interaction with diuretics causes….?
a decreased effect
Morphine interaction with tricyclic anti-depressants causes….?
increase in the analgesic activity
Morphine interaction with CA-antagonists causes….?
increase in the analgesic activity
Morphine interaction with rifampicin causes….?
increased metabolism of morphine
Morphine interaction with other drugs causes…?
delayed absorption of the other drugs
opioid analgesics ______ the cough reflex (2)
decrease
ex. codiene
opioid analgesics ______ secretions. which ones?
decrease
- intestinal
- biliary
- saliva
Can opioid analgesics be used pulmonary edema? (4)
- yes
- reduces preload and afterload
- relieves pulmonary and cardiac congestion
Can opioids be used for narcosis hypnosis and coma?
yes
Codiene/dihydrocodeine is a _____ derivative
morphine
Codiene/dihydrocodeine has ____ affinity for _____ receptor
less affinity
μ receptors.
Codiene/dihydrocodeine effects? (3)
- Antitussive: central action
- Analgesic: association with acetaminophen or ASA
- Antidiarrheal: constipation
Codiene/dihydrocodeine has analgesic associations with …? (2)
- acetaminophen
- aspirin
What has a higher risk of addiction? morphine or codeine?
morphine
What has a higher risk of respiratory depression? morphine or codeine?
morphine
DEXTROPROPOXYPHEN is a ______ opioid
minor
DEXTROPROPOXYPHEN has analgesic efficacy similar to ______
codiene
Which is better, dextropropoxyphen or codiene?
both have same advantages
When do we use tramadol?
moderate pain
What is the duration of action for tramadol?
6-8hrs
Tramadol has a low risk of .. (3)
- respiratory depression
- constipation
- urinary retention
Tramadol adverse effect
tachycardia (high HR)
Tramadol contraindications
myocardial infarction
What is the alternative to morphine but 10 times less potent?
MEPERIDINE = PETHIDINE
Which opioid is useful in biliary-pancreatic colic pain?
MEPERIDINE = PETHIDINE
Which opioid is useful in lower myocardial infarction
MEPERIDINE = PETHIDINE
Which opioid has a higher risk of respiratory depression and dependence?
MEPERIDINE = PETHIDINE
After metabolism, MEPERIDINE = PETHIDINE metabolites can cause.. (2)
- Cardiotoxicity: tachycardia
- Neurotoxicity: convulsions.
Which opioid does not cross the placental barrier?
MEPERIDINE = PETHIDINE
Which drug is 100 times more potent than morphine
fentanyl
Fentanyl treats what kind of pain?
Moderate to severe pain
fentanyl has ___ lipid solubility
high
fentanyl has ___ cardiotoxicity
little
Which opioid is frequently used in anesthesia?
fentanyl
What are the routes of administration for fentanyl? (2)
- IV
- transdermal (90% biodisponibility) every 2-3 days
Describe the fentanyl transdermal patch
- 90% biodisponibility
- path changes 2-3 days
Fentanyl is used as an alternative in elderly and pain oncology patients because…
less constipation than morphine
Which opioid causes less constipation than morphine?
fentanyl
Which opioid is similar to morphine, but with less cardiovascular effects?
buprenorphine
Buprenorphine is useful in treating what type of pain?
moderate-severe (transdermal 35-70 mcg/h)
What opioid is useful in treating opioid dependence and through what route?
- buprenorphine
- sublingual
Describe buprenorphine absorption
- oral =low
- better sublingual, dermal and IV
Where is buprenorphine metabolized?
-liver
How is buprenorphine eliminated?
biliary elimination
Burenorphine adverse reactions:
Same adverse reactions as morphine but less intense
How does Naloxone work?
-immediate reversal of CNS depression
How does Naltrexone work?
Prevention of opioids subjective effects
What is the route of administration for naloxone?
Parenteral
What is the route of administration for naltrexone?
oral
When is naloxone used? (2)
acute treatment
-respiratory depression from full agonist intoxication/overdose
When is naloxone used?
patient detoxification and addiction to opioids and
in chronic alcoholism
Intoxication/overdose of opioids appears in … (3)
- heroin addicts
- after IV adminsitration of potent opioids (ex. morphine or fentanyl)
Symptoms of opioid intoxication/overdose? (3)
- Decreased level of consciousness
- Respiratory depression
- Miosis ( Pinpoint pupils)
opioid antidote
Naloxone IV bolus
Which opioid is used to treat opioid dependence
and as an analgesic
Methadone
Methadone route of administration
oral
methadone is what type of opioid?
opioid agonsist
Which opioid has a longer duration?
methadone
Which opioid Doesn ́t have the euphoric effects associated with opiates?
methadone
Do we need to worry about overdose with methadone?
yes