Analgesic Agents

what kind of data is pain?

subjective, always

at what level of pain does it begin to hinder a person's capabilities?

5 or above

why do we need to control pain?

it causes unnecessary pain, along with activating SNS responses, decreasing immune function, weakening patients further, and decreasing compliance

when we medicate patients for pain, we medicate for _____ first, then we decide if we need to medicate for ______

pain; sedation

if there is pain, what do you assess?

COLDSPA; also management regimen, pain management history, effects of pain, pt pain goal, etc.

what are ways we can grade a patient's pain?

scales (0-10, simple descriptor, faces, oucher)

how frequently do we assess for pain?

- at the initiation or dose increase of treatment

- peak of analgesic effect

how do you assess patient and family beliefs towards pain management?

- determine issues and concerns by family and pt

- attempt to resolve problem

what do you do if you cannot resolve issues and concerns with family and patient pertaining to analgesic therapy?

if unresolved, determine the level of impediment it'll have on treatment

how often do you assess treatment concerns of the patient and family?

throughout the whole treatment

what is physical dependence?

pharmacological property causing the occurrence of withdrawal symptoms if there is abrupt discontinuation or administration of an antagonist

what is tolerance?

pharmacological effect in which, with repeated administration, increasing doses are necessary to provide the same effect (takes a long time)

with what kind of treatment does drug tolerance form?

long-term therapy

why is physical dependence not characterized as an addiction symptom?

because it is a physiological process that happens to everyone! if anyone's prescribed drugs are taken away abruptly, they will go into withdrawal

why isn't tolerance characterized as an addiction symptom?

because it is formed in patients, not just addicts; those in long-term opioid therapy due to chronic pain control eventually develop tolerance as well

what do we do if a patient develops tolerance to the prescribed amount of their drug?

we increase the dose so the same therapeutic effect can occur

what is addiction?

psychological dependence, a behavior syndrome characterized by drug craving, compulsive efforts to secure supply, hoarding, and drug-related interference with psychological, social, or physical function

what is the first level of the WHO pain treatment continuum?

pain level of 1-3; non-opioids, such as acetaminophen are used here with or without an adjuvant

what is the second level of the WHO pain treatment continuum?

pain level of 4-6; mild to moderate opioids are used here with or without a non-opioid and an adjuvant

what is the third level of the WHO pain treatment continuum?

pain level of 7+; moderate to severe opioids are used here with or without a non-opioid and an adjuvant

if a patient described their pain at a level of 8, how would you treat them, based off of the WHO pain treatment continuum?

you would automatically start treating them with a class 3 opioid for their severe pain with or without a non-opioid/adjuvant; you would not start with a non-opioid in level 1 and move up

what, in general, are the two types of analgesics?

- nonopiod analgesics

- opioid analgesics

where do nonopioid analgesics work? what do they do?

the periphery; they affect prostaglandin synthesis

where do opioid analgesics work? what do they do?

the CNS; they bind to mu, kappa, and delta receptors

how are non-opioid and opioid analgesics used?

they are either used separately or concurrently! they are used together to create a pain relief response in both the CNS and PNS

what type of effect does acetaminophen have?

analgesic, antipyretic

does acetaminophen relieve inflammation?

no; it does not have anti-inflammatory effects

what is acetaminophen use to treat?

osteoarthritis

what is the maximum dose of acetaminophen in one day for a healthy patient with good liver function?

4000 mg/day

what is the maximum dose of acetaminophen in one day for a patient with sub-par liver function?

2000 mg/day

what does a patient risk of they go over 4000 mg/day of acetaminophen?

hepatotoxicity

what is the IV version of acetaminophen?

ofirmev

who is best for IV acetaminophen use (ofirmev)?

works well for those who cannot take PO meds, such as those who are early post-op

what is the antidote for acetaminohpen overdose?

acetylcysteine

why is acetaminophen used frequently with opioids?

because it allows for pain relief in both nervous systems

what is COX?

cyclooxygenase

where is COX found?

in all tissues in the body

what does COX do in general?

it encourages synthesis of prostaglandin

what does COX 1 do?

presents itself in all tissues, protecting gastric mucosa, supporting renal function, and promotoing platelet aggregation

what does COX 2 do?

mediates inflammation, pain, and fever response at the site of tissue injury/brain

which COX is good and which is bad?

COX 1 = good; COX 2 = bad

what happens if we inhibit COX 1?

- inhibit protection of the mucus lining, thus increasing risk of peptic ulcers

- decrease platelet aggregation, which means that there is an easier chance at bleeding

what drugs are cyclooxygenase inhibitors?

aspirin and NSAIDs

what is the most common salicylate?

aspirin

what kind of effects do salicylates have on the body?

analgesic, antipyretic, anti-inflammatory, and suppresses platelet aggregation

how long does it take for the initial analgesic effect of salicylates to occur?

one hour

how long does it take for the max anti inflammatory effect to occur in a salicylate?

two weeks

salicylate uses?

rheumatoid arthritis, pain, stroke prophylaxis, MI, TIA, angina, dysmenorrhea

salicylate ADRs?

GI upset, bleeding

what is salicylate toxicity? what can it cause?

salicylism; causes tinnitus (ear ringing), sweating, HA, and dizziness

salicylate interactions?

HIGHLY protein bound

what are NSAIDs?

non-steroidal anti-inflammatory drugs

what do NSAIDs inhibit?

COX 1 and 2

what effects do NSAIDs have?

analgesic, antipyretic, and anti-inflammatory

how long does the initial effect of NSAIDs take?

1 hour

how long does the maximum anti-inflammatory effect of NSAIDs take?

2 weeks

NSAIDs uses?

rheumatoid arthritis, osteoarthritis, pain, fever, bursitis, tendonitis

NSAIDs ADRs?

GI upset, ulceration, bleeding, renal failure, anaphylaxis

what do we need to know about responses to NSAIDs?

they are individualized; if one doesn't work, don't automatically assume they all don't work -- try another

how early do patients stop taking aspirin/NSAIDs before surgery? why?

1-2 weeks depending on the effects; aspirin and NSAIDs decrease platelet aggregation, which could lead to unnecessary extra bleeding during operation

what are the NSAIDs you need to know for this exam?

- ibuprofen

- naproxen

how do we prevent salicylate and NSAIDs side effects?

- patient must remain upright for 15-30 minutes and take medication with food, milk, and a glass of water

- watch for black/tarry stool and avoid with alcohol use

what children would not take a salicylate or NSAID? why?

children with varicella or flu-like symptoms must avoid salicylates and NSAIDs because it can cause Reye's Syndrome, which can be fatal

what does black/tarry stool indicate?

GI bleed

how do we prevent GI effects from NSAIDs?

give NSAIDs with H2 antagonists, PPIs, or misoprostol

what cardiovascular effects can NSAIDs cause?

increase in blood pressure due to hypervolemia from sodium and water retention

what does NSAID bleeding potential depend on?

the amount and length of effect; it varies with each drug

what are adjuvants?

medications that work in combination with analgesics to increase their effect

what three effects can adjuvants add to analgesic medication?

1. enhance efficacy of other agents

2. add analgesic effects

3. treats concurrent symptoms

what types of analgesic adjuvants are there?

- tricyclic antidepressants

- antiepileptic/anticonvulsant drugs (most common)

- local anesthesia

- corticosteroids

- antispasmodics and skeletal muscle relaxants

- antihistamines

- benzodiazepines

topical agents

- bisphosphonates/radionucleotides for bone metastasis

which adjuvants do we use sparingly?

- antispasmodics and skeletal muscle relaxants

- antihistamines

- benzodiazepines

what adjuvants are used for bone metastasis?

bisphosphonates/radionuclides

which adjuvants are used to treat neuropathic pain?

gabapentin, pregabalin

which adjuvant is used to treat fibromyalgia?

pregabalin

what are the three classifications of opioids?

- opioid agonist

- opioid antagonist

- opioid agonist/antagonist

what type of pain do opioids treat?

moderate to severe pain

what do opioids bind to?

mu opioid receptors in the CNS

what is desirable about opioids?

- no ceiling effect

- no major organ dysfunction

- generally manageable side effects

what major organ is acetaminophen linked with?

the liver

what major organ are NSAIDs linked with?

the kidney and abdomen

what step 2 opioid do you need to know for this exam?

hydrocodone/acetaminophen

what are step 2 opioids used for?

moderate pain; 4-6 on a pain scale

what is the most constipating and emetogenic opioid?

codeine

why is hydrocodone/acetaminophen the most desirable step 2 opioid?

it's stronger than codeine, is available in varying doses, and is limited by acetaminophen content (combo drug)

what type of analgesic is tramadol?

a centrally acting non-opioid analgesic

what does tramadol bind to?

mu opioid receptors

what does tramadol do?

binds to mu receptors and inhibits the reuptake of serotonin and norepinephrine to the CNS

what indicates the use of tramadol?

moderate-moderately severe pain

what is tramadol equianalgesic to?

tylenol with codeine #3

what is the normal dose of tramadol?

50-100mg q4-6hr

what is the maximum dose of tramadol that can be given?

400mg/day

tramadol onset time?

1 hour

tramadol peak time?

2-3 hours

what is tramadol's DEA schedule?

lol sike it doesn't have one

what can tramadol cause?

seizures at therapeutic doses

who is at risk for seizures induced by tramadol use?

those with a decreased seizure threshold or those who are taking drugs that lower this threshold

what forms is tramadol available in?

long acting and as ultracet (the combo version with acetaminophen)

what is tramadol considered?

a dual-acting analgesic

what is tapentatol indicated by?

moderate to severe pain

what kind of opioid is tapentatol?

level 3 opioid