M4 study guide Flashcards
What receptors do opioid analgesics affect?
MU + Kappa
What are the effects of of activation of MU receptors?
Pure agonists produce analgesia, respiratory depression, sedation, physical dependence, slowed GI motility
How do opioid analgesics affect receptors?
acts primarily by activating MU receptors, also producing a weak activation of Kappa receptors
Best practices r/t use of topical anesthetics
minimize the amount being absorbed to avoid toxicity can be done by 1. apply the smallest amt 2. avoid application to large surface areas 3. avoid applications to broken or irritated skin 4. avoid strenuous exercise, wrapping the site, heating the site-all of which can accelerate absorption through increasing skin temp
Name some topical anesthetics
Lidocaine, tetracaine, cocaine
What are topical anesthetics used for?
Used to relieve pain, itching, and soreness of various causes including; infections, thermal/sunburns, diaper rash, wounds bruises, insect bites, plant poisoning
Complications r/t topical anesthetics?
Can be absorbed and produce serious life threatening effects. Cardiac toxicity can result in bradycardia, heart block, or cardiac arrest. CNS toxicity can result in respiratory depression, seizures, coma
Risk for toxicity increases w/ amount absorbed, determined primarily by:
- Amount applied 2. Skin condition 3. Skin temp
What is the reward circuit?
A system that normally serves to reinforce behaviors essential for survival
What is the major neurotransmitter released on the reward circuit?
Dopamine
Neurotransmitter effects on the reward circuit in those with SUD
Drugs can activate the circuit and cause dopamine release (may be 2-10x as much as what normally is released)
When the system is activated this causes a tendency to repeat behavior, w/ repeated action over time the system under goes synaptic remodeling, thereby consolidating changes in brain function
What occurs if the brain is put into excessive amounts of activation of the reward circuit in someone with SUD
The brain will 1. produce less domapine 2. reduce the number of dopamine receptors
What are the effects of alcohol on the CNS
depression of CNS and activation of reward circuit
What 3 receptors/neurotransmitters are involved w/ alcohol and CNS
GABA-inhibitory neurotransmitter-alcohol binds to GABA causing CNS depression
Glutamate receptors-alcohol binds to glutamate receptors it blocks excitation and reduces CNS activity
5-HT3 receptors-rewarding effects of alcohol. Triggers the reward circuit
All 3 of these promote release of dopamine
GABA, 5-HT3 receptors, Glutamate receptors
How are migraines treated
Treatment is based on severity and functional improvement.
Abortive therapy + Preventative therapy
Mild migraine
NSAID e.g aspirin, naproxen
Moderate Migraine
DHE or Ergotamine (ergot alkoloid), NSAID combo products
Severe Migraine
Metoclopramide, Triptans-Imitrex (First line drug tx migraines), NSAIDS (ketoralac), Ergotamine or DHE
How often should you use abortive meds for migraines
no more than 1-2 times a week
Antiemetics and Migraine therapy
important adjuncts to help treat migraines
Non specific analgesics
Abortive therapy
NSAIDS + NSAID combos e.g aspirin
Opioid analgesics
Migraine specific drugs
Serotonin receptor agonists (triptans)
Ergots
Prophylaxis meds for migraines
Beta blockers-first line drug (propanolol used most often)
AEDs-Divalproex and Topiramate have the stongest efficacy
Tricyclic anti-depressants
Estrogens
CGRP receptor antagonists
Vasoconstrictors and local anesthetics
Vasoconstrictors (epinephrine) decrease local blood flow + delays systemic absorption of an anesthetic
What 2 benefits does delaying absorption of local anesthetics have
Prolongs anesthesia and reduces risk of toxicity
Opioid agonists
Activates MU and Kappa receptors
e.g. morphine, codeine, meperidine
Produces analgesia, euphoria, sedation, resp depression, physical dependence, and constipation
Opioid antagonist
Antagonist at MU and Kappa receptors
e.g. Naloxone
Reversal of respiratory depression and CNS depression caused by overdose of opioid agonist
Methyllnatrexone
used to treat constipation induced by opioids
Is a opioid antagonist
Migraine pain
Moderate-severe lasting up to 3 days
Migraine character
Throbbing, unilateral or biltaeral
Migraine prodrome
Aura: visual field cut, flashing lights, zig zags
Migraine Associated symptoms
N/V, photophobia, phonophobia
Migraine precipitating factors
Anxiety, stress, fatigue, menstruation, ETOH, tyramine containing foods
Migraine epidemiology
More severe/common in women + famillial hx
Migraine aggravating factors
Physical activity
Agonist-Antagonist
When administered alone they produce analgesia, if given to a patient taking a pure agonist, these drugs can antagonize analgesia cause by the pure agonsist
Pentazocine, nalbuphine, butorphenol
Agonist-antagonist drugs
antagonist at MU + agonist at Kappa
Buprenorphine
Partial agonist
Partial agonist at MU + partial agonist/ weak antagonist at Kappa
Tolerance
Results from regular drug use, can be defined as a state in which a particular dose elicits a smaller response that it did with initial use
As tolerance increases, higher and higher doses are needed to elicit desired effects
Cross Tolerance
Tolerance from one drug confers tolerance to another
generally develops among drugs within the same class
Withdrawal syndrome
constellation of s/s that occurs in physically dependent individuals when they discontinue drug use
Physical Dependence
Defined as a state in which an abstinence syndrome will occur if drug is discontinued
Takes place as a result of prolonged drug exposure
Psychological dependence
An intense subjective need for a particular psychoactive drug
Cross-dependence
Ability of one drug to support physical dependence on another drug. Generally exists among drugs in the same pharmacologic family
How is SUD defined
A cluster of cognitive, behavioral, and physiological symptoms with continued use despite significant substance related problems
Dependence is not required but may be present
All dependent people do not have SUD
SUD is not equivalent to addiction
Preferred therapies for patients with chronic pain
Non pharmacologic therapy and nonopioid therapy should be used to treat chronic pain before starting opioid therapy
Current recommendations suggest initiating therapy with IR medications first
Use of nonopioid adjuvant meds should be continued to maximize pain control
Naloxone when given to someone who is physically dependent on opioids
Naloxone will precipitate an immediate withdrawal reaction
an excessive dose can transport a patient from a state of poisoning to a state of acute withdrawal
Naloxone
Opioid antagonist, used to reverse effects of opioid overdose
How should naloxone be administered?
Series of small doses rather than one large dose
Side effects/ adverse effects of opioids including morphine
Constipation
Respiratory depression-can occur 90 mins after PO ingestion
urinary retention-encourage pt to void Q4
tolerance and dependence-happens w/ continued use
Sedation
Euphoria
Orthostatic hypotension
Emesis-promotes n/v; pt may need antiemetics
Practice considerations when prescribing opioid drugs to patients with non cancer related pain
Opioids only after non opioids have failed
1 prescriber 1 pharmacy
discuss benefits/risks
Good documentation
3 principles of Treatment of headache
- abort or prevent headache
- patient responses vary
- some HA drugs can cause dependence
Schedule 1 drugs
high potential for abuse, no approved medical use in US, therefore not prescribed e.g. cocaine, heroin
Schedule 2 drugs
Must be typed of filled in ink or indelible pencil and signed by the prescriber, or electonically
Oral prescriptions only in emergencies, must obtain written within 72 hours
cannot be refilled
cant write multiple prescriptions on the same day for the same patient and the same drug
Schedule 3 drugs
Oral, written, or electronic prescriptions; if authorized by the prescriber these medications can be refilled up to 5 time; refills must be made within 6 months of the original order
If additional meds are needed beyond the amt. provided for in original prescription a new prescription must be written
Schedule 4 drugs
Same as schedule 3 drugs
Schedule 5 drugs
Same rules as schedule 3 and 4
Can be dispensed by a pharmacist if certain criteria are met.
The amt. dispensed is limited
Recipient is at least 18 years old
The pharmacist writes and initials a record indicating the date,name, amt. of drug, and the name and address of the recipient
State and local laws do not prohibit dispensing schedule 5 drugs w/out prescription
What is Fentanyl
Opioid agonist, 100x more potent than morphine
can be given transdermal, parenteral, transmucosal, intranasal
Schedule 2 drug
Adverse Rx: respiratory depression, sedation, constipation, urinary retention, nausea
Drug-drug interaction involving CYP system in patients receiving Fentanyl
Fentanyl is metabolized by CYP3A4, therefore fentanyl can be increased by CYP3A4 inhibitors (Ketoconazole and Ritonavir) these patients should be monitored closely for signs of respiratory depression and other signs of toxicity
Nicotine replacement therapy (NRT)
Nicotine gum
Nicotine lozenge
Nicotine patch
Nicotine inhaler
Nicotine nasal spray
Nicotine Free products
Sustained release bupropion
Varenicline (Chantix)
Varenicline (Chantix)
taken to decrease nicotine cravings and suppress symptoms of withdrawal
