!Neuropharm Opoids Flashcards
Opoids
Narcotic analgesics and re indicated to reduce pain (chronic pain and palliative, but can be used to wean drug dependent patients
Indications for opoids
Pain, weaning, cough, diarrhea
Types of opoids
Morphine, fentanyl-general anesthesia , but can also reduce pain without loss of consciousness , but may induce tolerance or dependence
Codeine, heroin, methadone, meperidine, dextromethorphan, and diphenoxylate
MOA opoids
Exert their action due to their agonist activity at mu, kappa, and delta receptors
Receptor activity works to decrease synaptic transmission and inhibit release of acetylcholine, NE, 5HT, glutamate, and substance P
Side effects opoids
Respiratory depression, addiction, miosis and constipation
Indications for opoids
Pain, weaning, cough, diarrhea
Methadone
Can be used to wean patients so don’t get withdrawal syndrome
Loperamide and diphenoxylate
Treats persistent diarrhea as a common side effect is constopation
MOA opoids
Mu kappa and delta receptor agonists
Each receptor has distinct subtypes and different drugs may have mixed properties or partial agonist activity
Ok
Opoids and decreased synaptic transmission
Opoids work to open k channels and close ca channels, decreasing synaptic transmission. They inhibit release of acetylcholine, NE, 5HT, glutamate and substance p.
PANGS
Side effects opoids
Respiratory depression
Addiction
Miosis
Constipation
Opoid and respiratory depression
Direct inhibition of the brainstem respiratory center
Becomes less sensitive to carbon dioxide, leading to decreased hypoxia drive, respiratory rate, tidal exchange, and minute volume
Why get addicted to opoid
Pleasure produced by opoids, espicially when self administered
Physical dependence, as tolerance may build gradually with repeated use.
Opoids and constipation
Decrease GI motility and increases tone, specially anal sphincter
Miosis and opoid
Pinpoint pupils
Except in meperidine
Opoids act on mu and k receptors to stimulate the oculomotor nucleus to constrict pupils
Opoid
Depressant drug and analgesic that can cause constipation, miosis, nausea and vomiting
Opoid toxicity
Lead to cns depression as well as respiratoy depression.
Common causes of opoid toxicity
Overdose on morphine or heroin
Naloxone (narcan)
Mu opoid receptor antagonist used for reversal of acute life threatening opoid toxicity
Naltrexone
Also antidote for opoid toxicity
But it is an opoid receptor antagonist used for dependence treatment rather than in the emergent treatment of opoid overdose
Antidote for opoid toxicity
Naloxone
Naxolone
Opoid antagonist for reversal
To counteract life threatening depression of the cns and respiratory depression
Injected
Morphine
Potent medication used for pain relief . Opoid receptor antagonist
Mechanism of opoid receptor agonist morphine
Mu k and delta
With mu being primary target
Indications for morphine
Pain , MI
Pain and morphine
Chronic and severe pain such as with cancer, pancreatitis or traumatic injuries
How is morphine delivered with chronic pain
Patient controlled anesthesia (PCA) pump which allows continuous dosing based not he patients perceived level of pain up to a maximum dose
MI and morphine (also angina and pulmonary edema)
- it decrease the anxiety level and pain experienced by the patient which decreases stress and sympathetic response
- has vasodilation effects all of which decrease the oxygen demand of the heart.
Side effects morphine
Nausea and vomiting, CNS depression, biliary colic, constipation, increase intracranial pressure, pupillary constriction, hypotension
Why nausea and vomiting with morphine
May stimulate the chemoreceptors trigger zone (CTZ- in the brain. Slow administration decreases the side effect
Morphine and biliary colic
May cause spasm of the bile duct and subsequently serious abdominal pain as bile is unable to leave the gall bladder into the duodenum
Morphine and hypotension
Vasodilator effects
Tramadol
Unique, centrally acting medication that works on multiple neurotransmitters.
Indications for tramadol
Chronic pain , analgesic uses (RA, fibromyalgia)
Tramadol is a racemic mixture of two tramadol enantiomers
- one works to inhibit serotonin reputable and enhance its release
- othe inhibits NE reuptake
MOA tramadol
Weak opoid agonist at mu receptors
Influence NMDA, muscarinic and nicotonic receptors that lead to its analgesic effects
Side effects of tramadol
Dose independent increased risk of seizure as this drug decreases seizure threshold in patients
Indications for tramadol
Chronic pain
RA and fibromyalgia
MOA tramadol
Weak opoid for mu receptors producing analgesic effects
Tramadol has synergistic effects with numerous other receptors as it also affects what receptors
Nicotonic, muscarinic, NMDA
Tramadol inhibits serotonin and NE reuptake
Two enantiomers. The modulation of these various receptors and NT in combination that help tramadol exhibit its effects
Side effects tramadol
Seizure by lowering threshold
Codeine
Strong opoid
How does codeine work
Activating mu receptors in the CNS and periphery to produce analgesia
Indication for codeine
Mild to moderate pain and can also be used as an antitussive
Side effects codeine
Sedation, constipation, and constriction of the pupils
What may codeine be combined with to generate a greater analgesic effect
Combined with non opoid analgesics such as acetaminophen and asprin
How does codeine work
Activating mu opoid receptors int he CNA and periphery, producing pain relief , sedation and respiratoy depression
Indications for codeine
Mild to moderate pain
Cough
Why does codeine suppress cough
Acts in medulla to suppress coughing. Though the antitussive effect may be a desired outcome of codeine therapy, lack of coughing can cause secretions to a ccumulate inthe airway.
Side effects codeine
Sedation, constipation, miosis
Cosine and impaired vision
Miosis
Consideration 1 of codeine
Close monitoring with breast feeding-can cause unsaf levels of morphine in breast milk
Babies who become intoxicated may be lethargic , sleepy, disinterested in eating and have difficulty breathing
Consideration 2 with codeine
Often combined with non opoids
Like acetaminophen or aspirins
Have differen MOA so when combined they can relieve pain better than any of the medications alone
Ok
Meperidine (Demerol)
Strong opoid agonist that works by activating my receptors in the central nervous system and periphery to produce analgesia
Indication for meperidine (Demerol)
Moderate to severe pain
Post anesthesia shivering
Side effects meperidine
Sedation, constipation, CNS depression, tremors
Who should meperidine be used cautiously in
Renal failure as metabolites can accumulate int he kidneys causing toxicity
What drug should meperidine not be taken with
MAO inhibitors, DDRI, tricyclic antidepressants, due to increased risk for serotonin syndrome, coma and death
Mechanism of meperidine
Opoid receptor antagonist
Activating mu opoid receptor in cns and periphery producing pain relief, sedation, respiratory distress, cough suppression and decreased intestinal peristalsis
Indications for meperidine
Moderate to severe pain
Post anesthetic shivering
How does meperidine help with post anesthesia shivering
Reduce shivering threshold
Side effects meperidine
Tremors, constipatio, CNS depressant, sedation
Considerations with meperidine 1
Short term administration-prevent toxicity take less than 48 hrs at a time
Do not excess 600 mg/24 hour
Why is meperidine preferred for obstetric use
Less likely to depress fetal respiration and uterine contractions, it is often the preferred opoid for obstetric use
Meperidine consideration 2
Increased risk of serotonin syndrome when taken with MAO inhibitors , SSRI, tricyclic antidepressants
Get excessive activation or serotonin receptors and decreased reuptake of serotonin. As a result there is an increased risk for serotonin syndrome coma and death
When taken with consideration 3 for meperidine
Does NOT cause miosis
Unlike other opoid medications, no miosis or pupil constriction
Consideration 4 meperidine
Renal failure increases toxicity risk
Used cautiously in patients with renal failure as metabolites can accumulate in the kidneys causing toxicity
Butorphanol
Medication indicated to treat migraine headaches and severe pain in patients and is helpful in labor pains
MOA butorphanol
Mixed actions at the receptor level and acts as a partial agonist at mu and k receptors, while also being a competitive antagonist at mu receptors
Bc of butorphanol partial agonist/antagonist activity at mu receptors, it causes __ respiratory depression than full opoid agonist drugs
Less
Side effect of butorphanol
Withdrawal
Usually when patient also being treated with full opoid agonist medication
Why get adverse effects with mutorphanol
Competitive antagonist activity at mu receptors, competing with the adjunct opoid drug being taken, leading to withdrawal symptoms
Indications for butorphanol
Migraine
Severe pain
Labor
Butorphanol is more effective in women or men
Women
MOA butorphanol
Partial agonist at mu and full agonist at kappa receptors
Less respiratory depression due to drugs partial agonist/antagonist properties at mu opoid receptors
Side effect butorphanol
Withdrawal
If taking a full opoid agonist concurrently
At mu receptors butorphanol acts as a competitive antagonist and partial agonist
Thus.a patient also taking a fulll opoid agonist medication would experience butorphanol competing for opoid receptors, leading to withdrawal symptoms.
How treat withdrawal symptoms of butorphanol
Naloxone however overdose isn’t easily reversed
Naloxone (narcan)
Opoid antagonist that works by blocking opoid receptors int he body, effectively reversing side effects associated with opoid use, such as sedation and respiratory depression
Use of naloxone
Reverse opoid induced CNS depression and should be administered every 2-3 min until the desired patient response is observed.
Side effects naloxone (narcan)
Severe nausea, vomiting, excitability, symptoms of opoid withdrawal
MOA naloxone
Competitive opoid receptor antagonist
It is structurally similar to opoid drugs and works by competing with these medications for opoid receptor sites int he body
Opoid antagonist-blocks the action of opoid , effectively reversing side effects associated with these medications, such as respiratory depression, sedation, coma, and analgesia
Indications for naloxone
Opoid induced CNS depression
Reverses sedation , respiratory depression, and other CNS effects associated with opoid administration. If given prior to administration of an opoid , naloxone will block opoid receptors and will prevent the opoids drug from taking effect
Side effects naloxone
Severe nausea and vomiting (if administered too rapidly0
)
Excitable state
Opoid withdrawal symptoms
Considerations naloxone
Repeated dosing often required
IgE every 2-3 minutes until the desired response is obtained/observed
