Pharm - Pain & NSAIDs/Opioids Flashcards
What kind of drugs are step 1 on the analgesic ladder?
aspirin, acetaminophen, NSAIDs
What type of pain do step 1 drugs on the analgesic ladder address?
MILD pain
What kind of drugs are step 2 on the analgesic ladder?
weaker opioids
What type of pain do step 2 drugs on the analgesic ladder address?
mild to MODERATE pain
What are step 3 drugs on the analgesic ladder?
stronger opioids
What kind of pain do step 3 drugs on the analgesic ladder address?
Moderate to SEVERE pain
What should be used at each step of the analgesic ladder?
Combinations of medicines
What can the PT implement outside of the analgesic ladder to help with pain?
Non-medication options
What are the pharmacological effects of NSAIDs?
- reduce inflammation
- provide mild to moderate pain relief
- reduce body temp associated with fever
- reduce blood clotting by inhibiting platelet aggregation
What is the mechanism of action for NSAIDs?
inhibit synthesis of prostaglandins
What does the effect of prostaglandins depend on?
- organ or tissue involved
- receptor
- bodily function or physiological situation
What are prostaglandins?
fatty acid derivatives of arachidonic acid that have diverse hormone-like effects dependent on body region
Are prostaglandins present in most cells?
YES
What should we know about the prostaglandin half-life?
SHORT
Do prostaglandins have a short or long duration?
Short duration of action
What cells does prostaglandin ONLY affect?
Those that are close by
What are some of the varied effects of prostaglandins?
- add or subtract platelet buildup for blood clot formation
- vasodilation or constriction
- bronchoconstriction
- fever
- modulate pain perception
- cause uterine contractions
- inhibit gastric acid secretions
- modulate ?? in GI tract
- regulate several hormones
How do NSAIDs inhibit prostaglandin synthesis?
by inhibiting cyclooxygenase (COX 1 and COX2)
What does COX 1 enzyme do?
- expressed in most tissue
- regulates normal cell processes
When is COX2 enzyme expressed?
in response to injury/inflammation
What does low dose asprin do?
irreversably inhibits platelet cox 1
What side effects do COX 1 enzymes have on the GI mucosa?
- gastic protection
- increase mucus secretion
- increase bicarbonate
- increase mucosal blood flow
What can COX 1 inhibition cause?
- peptic ulcers
- GI bleeding
What can COX 1 and 2 enzymes do to the kidneys?
- afferent arteriolar vasodilatoin
- increase Na and water excretion
What side effects can COX inhibition have on the kidneys?
- na and water retention
- hypertension
- hemodynamic acute kidney injury
What are the cardiovascular effects that COX 2 enzymes have?
- vasodilation
- inhibit platelet aggregation
What are the cardiovascular affects that COX 1 enzymes have?
- platelet aggregation
- vasoconstriction
What side effects can COX 1 & 2 inhibition have on the cardiovascular system?
- stroke
- myocardial infarction
What are some COX 1 selective medications?
asprin
naproxen (ALEVE)
What are some nonselective NSAIDs?
- ibuprofen (advil, motrin)
What is an example of a 5-50-fold COX 2 selective medication?
Celecoxib
What is an example of a >50-fold COX 2 elective medication?
Etoricoxib (arcoxia)
Do Cox 1 selective or cox2 selective have more GI effects?
COX 1 selective
Do COX 1 selective or COX 2 selective medications have increased cardiovascular effects?
COX 2 selective
What do COX 2 selective NSAIDs do?
- increase risk for CV events
- decrease risk for GI side effects
What do semiselective NSAIDs do?
- increase affinity for COX2 but still retain activity for COX1
- use with caution in patients at increased CV risk
What do NON selective NSAIDs do?
- decreased risk for CV events
- increased risk for GI side effects
What do irreversible nonselective NSAIDs do?
- cardio-protective at low doses
- increased risk for GI side effects
What should we know about acetaminophen and its efficacy compared to aspirin and NSAIDs?
- equal efficacy to aspirin and NSAIDs for analgesia and antipyeretic effects
Does acetaminophen have GI effects?
no
What can happen with acetaminophen at high doses?
liver toxicity
What can nonopioids treat?
- mild/mod pain
What are examples of nonopioids?
- NSAIDs
- Acetaminophen
What can opioids treat?
moderate/severe pain
Are opioids controlled substances?
yes
What do opioids bind to?
specific CNS receptors
What are the sources of opioid analgesics?
- natural (opium poppy)
- synthetic
- semisynthetic
How do opioids work?
interact with opioids receptors and reduce intensity of pain signals and feelings of pain
What are some examples of natural opioid analgesics?
opiates
- morphine
- codene
What are some examples of opioids analgesics?
opioids
- methadone
- tramadol
- fentanyl
What are some examples of semisynthetic opioids?
opioids
- oxycodone
- hydrocodone
What does endogenous mean?
within the spinal cord
What are some endogenous receptors?
- mu
- kappa
- delta
What are the functions of mu receptors?
- supraspinal and spinal analgesia, sedation
- inhibition of respiration, slowed GI transit
- modulation of hormone and neurotransmitter release
What are the functions of delta opioid receptors?
- supraspinal and spinal analgesia, sedation
- modulation of hormone and neurotransmitter release
What are the functions of kappa receptors?
- supraspinal and spinal analgesia, sedation
- psychotomometic effects
- slowed GI transit
What are the endogenous opioid peptide affinity of mu receptors?
endorphins>enkephalines>dynorphins
What are the endogenous opioid peptide affinity of delta receptors?
enkephalins> endorphins and dynorphins
What are the endogenous opioid peptide affinity of kappa receptors?
dynorphins» endorphins and enkephalins
What are the ionic mechanics opioid analgesics?
opioid analgesics inhibit synaptic activity partly through direct activation of opioid receptors and partly through release of endogenous opioids
Where are all three types of receptors found?
- in high concentration in the dorsal horn
- in the brainstem
> medulla, locus ceruleus and midbrain periaqueductal grey
Where have mu receptors been found also?
on the peripheral terminal of sensory neurons
What are strong agonists for?
severe pain
What receptor do strong agonists have an affinity for?
Mu receptors
What are examples of strong agonists?
morphine, methadone, meperidine (demerol), fentanyl
What are moderate agonists for?
moderate pain
What affinity do moderate agonists have?
less affinity or efficacy
What are examples of moderate agonists?
- codeine, oxycodone
What are weak agonists for?
moderate pain
What affinity do weak agonists have?
less affinity or efficacy
What is an example of a weak agonist?
propoxyphene (darvon)
What is an agonist?
A drug which produces a pharmacological effect when combined with a receptor
What is an antagonist?
a drug which reduces the effect of an agonist
What are mixed agonist-antagonists?
- exhibit some agonist and some antagonist activity
What can mixed agonist-antagonists do?
provide pain relief without some side effects
What are some examples of mixed agonist-antagonists?
buprenophine, nalbuphine (nubain)
What do antagonists do?
block all opioid receptors
What are antagonists used for?
overdose and addiction
What are some examples of antagonists?
naloxone, naltrexone
What is the half life of codeine?
2.5-3 hours
What are the side effects of codeine?
constipation, nausea
What are prescribing considerations for codeine?
> 65mg may not be appropriate particularly in elderly
What is the potency of codeine relating to morphine?
15% of morphine
What is the half life of fentanyl?
10-20 mins
What are some side effects of fentanyl?
somnolence, diarrhea, nausea, constipation
What are some prescribing considerations for fentanyl?
fast acting transmucosal formulations are suitable for breakthrough pain
What is the potency of fentanyl compared to morphine?
80x more potent than morpine
What is the half life of hydromorphone?
2-3 hours
What are the side effects of hydromorphone?
somnolence, constipation, nausea, dizziness
What are the prescribing considerations for Hydromorphone?
metabolites can build up in those with compromised renal function
What is the potency of hydromorphone compare to morphine?
8-10x more potent than morphine
What is the half life of mepheridine?
3 h
What are the side effects of merpheridine?
tachycardia, mydriasis, dysphoria
What are some prescribing considerations for merpheridine?
normerperidine is neurotoxic, so meperidine should not be used to treat chronic pain syndromes
What is the potency of merpheridine compared to morphine?
Morphine is 10x more potent than merperidine
What is the half life of morphine?
2-3 h
What are some side effects of morphine?
sedation, conception, nausea, morphine toxicity
What are some prescription considerations for morphine?
should not be used in patients with renal dysfuction
What is morphine considered?
the standard by which other drugs are measured
What is the half life of oxycodone?
3-4.5 hours
What are some side effects of oxycodone?
constipation, fatigue, dizziness
What are some prescription considerations for oxycodone?
some patients may be “fast metabolizers”
What is the potency of oxycodone compared to morphine?
1.5-2x more potent than morphine
What is the half life of tramadol?
5.5-7 hours
What are some side effects of tramadol?
nausea, vomiting, constipation
What are some prescribing considerations for tramadol?
dual mechanism of action because these agents also inhibit serotonin and norepinepherine reuptake
What is the potency of tramadol compared to morpheine?
higher for neuropathic pain than for nociceptive
When are most pharmacokinetics well absorbed ? (method of intake)
when given by subcutaneous, intramuscular, and oral routes
What is there an extensive list of with some pharmacokinetics?
first pass effect
- may need a higher dose orally than parenteral
Where are pharmacokinetics widely distributed?
body tissue
Where are pharmacokinetics localized?
in higher concentration in higher perfused tissue (brain, lung, liver, kidneys, and spleen)
What are CNS effects of pharmacokinetics?
- analgesia
- euphoria
- sedation
- respiratory depression
- antitussive
- miosis (constricted pupils)
- N&V
- truncal rigidity
What are peripherial effects of pharmacokinetics?
- cardiovascular system
- GI tract
- smooth muscle
- renal
- pruritis (itching)
When can problems arise with opioids?
when used in combination with other CNS depressents
What is a relaxive contraindication of opioids?
use wit MAO (can cause serotonin toxicity)
What should we know about analgesic activity with agonist-antagonist drugs?
varied, less activity than strong gonists
What receptors are there for agonist-antagonist drugs?
- nalbuphine and pentazocine are kappa agonists with weak mu receptor antagonist activity
- Buprenorphine is a mu-receptor with weak kappa and receptor antagonist activity
What are the effects of agonist-antagonist drugs?
pain relief without SE
What are some qualities of anatagonists?
- pure opioid receptor antagonists
- have few other effects
- greatest affinity for mu receptors
What is the primary clinical use of antagonists?
in the management of acute opioid overdose
What is naltrexone also used for?
treatment of ethanol dependency
What are opioid clinical uses?
- analgesia
- cough suppression
- treatment of diarrhea
- management of acute pulmonary edema
- anesthesia
When are analgesic applications of opioids most effective?
- with mod/severe constant pain
- also appropriate for acute or chronic pain
- frequently alter the perception of pain
What is a benefit of oral administration?
easiest, most convinient
What is IM?
intramuscular
What are benefits of IV administration?
- more complete and rapid
What is PCA??
Patient Controlled Analgesia
What are adverse side effects of opioids?
- behavioral restlesssness, hyperactivity
- respiratory depression
- N&V
- increased intracranial pressure
- postural hypotension
- constipation
- urinary retention
- itching
What is addiction?
repeated seeking and ingestion of substance for mood-altering and pleasurable experiences
What is tolerance?
the gradual loss of effectiveness with repeated administration of therapeutic levels of morphine or its surrogates
What is physical dependency?
marked by a relatively specific withdrawal or abstinence syndrome
What is psychological dependency?
reinforced by the development of the physical dependency
- euphoria, indifference, and sedation tend to promote their compulsive use
What are symptoms of narcotic withdrawl?
- Body aches
- Diarrhea
- Fever
- Chills
- Insomnia
- Irritability
- Loss of appetite
- Nausea/vomiting
- Runny nose
- Shivering
- Sneezing
- Stomach cramps
- Sweating
- Tachycardia
- Uncontrolled yawning
- Weakness/fatigue
What are the characteristics of opioid overdose?
– Pupillary constriction,
comatose state, and respiratory
depression
When is opioid overdose confirmed?
- Overdose is confirmed if prompt recovery is gained through the use
of naloxone
What are some specific PT considerations for pain medications?
- Pain can negatively impact efficacy of PT
intervention - Total pain relief can negatively impact
efficacy of PT intervention - Intermittent pain control can result in
higher drug use with less pain control
*Need =Appropriate Type & Dose
*Timing for optimum PT rx
*Monitoring of effects, efficacy
What are some types of chronic pain?
Neuropathic pain
Migraines
Fibromyalgia
Trigeminal neuralgia
Central pain syndromes
Complex regional pain syndrome
What are some adjuvant analgesic medications?
- Anticonvulsants
- Tricyclic antidepressants
- Norepinephrine and serotonin reuptake
inhibitors - Muscle relaxants
- Antihistamines
- Local anesthetics
- Psychostimulants
- Nerve blocks
What is neuropathic pain?
burning or shooting
What is neuropathic pain associated with?
- associated with migraine, post-herpetic
neuralgia, diabetic neuropathy, peripheral
neuropathy, malignant nerve infiltration - May lead to continuous or stimulus-evoked
pain; pain is not necessarily related to the
amount of nerve damage - Allodynia may occur
What are some condition based pain medications?
- Migraines
- Fibromyalgia
- Trigeminal neuralgia
- Cancer-related pain
- OA and RA medications
- Gout medications
What are some abortive therapy migraine headache agents?
Abortive therapy
– NSAIDs – decrease inflammation
– Triptans – target serotonin (Imitrex)
– Ergot alkaloids - cause vasoconstriction of carotid artery beds (Ergotamine tartrate)
What are some preventive therapy migraine agents?
Preventative therapy
– Beta blockers
– Tricyclic antidepressants
– Monoamine oxidase inhibitor antidepressants
– Selective serotonin reuptake antidepressants
– Anticonvulsants
– Calcium channel blockers
– NSAIDs
What is fibromyalgia characterized by?
chronic muscle and joint pain,
extreme fatigue, and tender points
What are some medications for fibromyalgia?
Medications
– Anticonvulsants
* Gabapentin and pregabalin
– Selective serotonin and norepinephrine
reuptake inhibitor antidepressants
* Duloxetine (Cymbalta) and milnacipran
(Savella)
What is trigeminal neuralgia?
Tic douloureux – produces sudden, severe, recurrent unilateral face pain
What are some medications therapies for trigeminal neuralgia?
Medication therapy
– Anticonvulsants
* First line: carbamazepine (Tegretol)
* Second line: gabapentin and phenytoin
(Dilantin)
What is cancer pain described as? How do we manage it?
Cancer Pain
* Pain can be a mixture of acute pain related to the disease and pain related to the therapeutic interventions
* Non-pharmacologic therapies for managing pain include physical and cognitive modalities, nerve blocks
What are some pain medications for cancer?
- Opiates
- Corticosteroids
- Anticonvulsants
- Tricyclic antidepressants
- Norepinephrine and serotonin reuptake inhibitor
antidepressants - Muscle relaxants
- Antihistamines
- Anesthetics
- Psychostimulants