Pain Flashcards
Types of pain (2 categories)
Nociceptive
Pathophysiologic
What is nociceptive pain?
Pain that occurs when sensory nerves (nociceptors) identify tissue damage because injured tissue (visceral-organ, skin, muscle, joint, bone, etc) releases
PGs
substance P
histamine
and other substances
which stimulate nocireceptors to send impulses to the brain signaling pain=feeling pain
What is pathophysiologic pain
Pain due to damage or malfunctioning of the nervous system.
AKA neuropathic pain
Includes: fibromyalgia, diabetic neuropathy, chronic headaches, drug induced toxicities, and others
Acute vs chronic pain
Acute pain is typically nociceptive, and the pain typically goes away when the cause has been resolved
Chronic pain persists beyond normal healing time (usually 3 months) and sometimes without acute/visible injury (eg. OA, crushed lumbar, diabetic neuropathy, etc)
Chronic pain is divided into:
cancer pain
non-cancer pain
Treating pain
Pain is subjective-pain scales are useful to assess pain severity
Mild 0-3:
non-opioid
+/- adjuvant
Moderate 4-6
opioid for mild-moderate
+/- non-opioid
+/- adjuvant
Severe 7-10
opioid for moderate-severe
+/- non-opioid
+/- adjuvant
non-opioid analgesics
acetaminophen
NSAIDs
Adjuvants for pain management
Commonly used for neuropathic pain
- anti-epileptic drugs (gabapentin, pregabalin, carbamazepine)
- analgesic antispasmodics (Backofen, cyclobenzaprine, tizanidine)
- sedating antispasmodics (carisoprodol, methocarbamol)
- SNRIs and TCAs (milnacipran, amitriptyline, desipramine, duloxetine)
- topicals (lidocaine, capsaicin, methyl salicylate)
ACetaminophen MOA
Reduces pain and fever BUT is NOT anti-inflammatory
MOA not well defined but is thought to inhibit PG synthesis
Name agents for mild pain (rx and OTC)?
Acetaminophen (Tylenol, Ofirmev, FeverALL)
+ Hydrocodone (Vicodin, Norco, Lortab)
+ Oxycodone (Percocet, Endocet, Primlev)
+ codeine (Tylenol #2, 3, 4)
+ tramadol (Ultracet)
+butalbital/Caffiene (Fioricet)
+benadryl (Tylenol PM)
Brand name of Acetaminophen?
Tylenol, Ofirmev, FeverALL
Brand name of Acetaminophen + Hydrocodone?
Vicodin
Norco
Lortab
Brand name of Acetaminophen + Oxycodone?
Percocet
Endocet
Primlev
Brand name of Acetaminophen + Codeine?
Tylenol #2, 3, 4
Brand name of Acetaminophen + Tramadol?
Ultracet
What’s the max daily dose of Acetaminophen in adults?
Box: Keep below 4,000 mg/day (4g/day)
To prevent hepatoxicity
Doses >2g/day can increase INR in warfarin patients
Children’s dosing of Acetaminophen? Max daily dose?
10-15 mg/kg Q4-6H
Max 5 doses/day
What’s the conc of Acetaminophen in infants and children’s suspension?
160mg/5mL
SEs of Acetaminophen use?
Hepatoxicity (with overdose), SJS/TEN, nephrotoxic-rare but seen in chronic overdose (safer than NSAIDs)
What’s the DOC in pregnancy for pain?
Acetaminophen
Antidote for Acetaminophen overdose?
N-acetylcysteine (NAC, Mucomyst, Cetylev, Acetadote)
comes oral and IV
Moa of N-acetylcysteine (Antidote for Acetaminophen overdose)?
Restores intracellular glutathione (acts as a glutathione substitute)
Rumack-Matthew nomogram uses serum acetaminophen level vs time since ingestion to determine if hepatotoxicity is likely and the need for NAC
MOA of Aspirin and other NSAIDs (not acetaminophen)?
Aspirin - irreversibly blocks COX 1=decrease TxA2 (which is required for platelet activation & aggregation)
Other NSAIDs - reversibly block cox 1 &2 (non-selective) or COX-2 only (selective)
COX1 protects the gastric mucosa so selective (only cox2) NSAIDs decrease GI risk
While cox-2 selective agents have lower GI bleeding risk, but what risk increases with their use?
Cardiovascular risk- MI and stroke
List NSAIDs, Salicylates agents
Aspirin (Acetylsalicylic acid) - Bayer, Ascriptin, Bufferin, Ecotrin, Durlaza
Non-Acetylated Salicylates:
Salsalate
Mg Salicylate (Doans)
Choline Mg Trisalicylate
Diflunisal
Salicylate salts
Risk that increases with NSAIDs use. Groups with highest risk?
GI bleeding
Elderly
Hx of GI bleed
Taking systemic steroids
On SSRIs or SNRIs
NSAID SE (all NSAIDs)
- decrease renal clearance-ALL should be used cautiously or avoided in renal failure
- increase blood pressure-caution in controlled HTN, avoid in uncontrolled HTN
- premature closure of ductus arteriosus=HF in baby-Don’t use in 3rd trimester of pregnancy
- nausea-salicylates are worse than other NSAIDs. To minimize, take w/ food, enteric coated, or buffered products
Salicylate SEs?
Avoid with NSAID hypersensitivity, nasal polyps, asthma Avoid in children/teens -Reye's SJS/TEN Increases bleeding risk GI ulceration & bleeding can occur
Dyspepsia Heartburn Bleeding Nausea BP may increase (monitor) CNS effects Photosensitivity Edema Hyperkalemia Blurred Vision
OVERDOSE: tinnitus
List agents under NSAIDs, others
Ibuprofen (Motrin, Advil)
Naproxen Na
Brand name of Ibuprofen (NSAIDs, others)?
Motrin
Advil
Brand name of Naproxen-Esomeprazole?
Vimovo
PPI used to protect gut from damage caused by NSAID
How are all forms of Naproxen dosed?
All given BID
Advantage of Naproxen formulations?
Relatively lower cardiac risk
Agents under non-selective NSAIDs?
IN SKIP- block Cox1 and Cox2
GI risk, CV risk, Post CABG risk
Ibuprofen (Motrin, Advil, Caldolor, NeoProfen)
Naproxen (Aleve, Naprelan, Naprosyn)
Sulindac
Ketorolac (Toradol, Sprix)
Indomethacin (Indocin, Tivorbex)
Piroxicam (Feldene)
Brand name of Diclofenac?
Box-Avoid in women of child bearing potential
Voltaren Cambia Cataflam Enova many others
+misoprostol (Arthrotec)
misoprostol is used to replace gut protective PG to decrease GI risk. CAN cause uterine contarctions-abort pregnancy. Also causes cramping & diarrhea
Brand name of Indomethacin
Indocin
Tivorbex
High risk for CNS side effects- avoid in psych pts
Brand name of Piroxicam
Feldene
Brand name of Ketorolac
Toradol
Sprix NS
SEs unique to indomethacin (Indocin)?
High risk for CNS SEs (avoid in psych conditions)
GI toxicity
SEs unique to Piroxicam (Feldene)?
High risk for GI toxicity and severe skin rxns (including SJS/TEN)
SEs unique to Ketotolac (Toradol)?
Increase bleeding
Acute renal failure
Liver failure
Anaphylactic shock
Box-only for short term mod-severe pain as continuation of IV or IM Tx (MAX COMBINED duration IV+IM+PO+Nasal 5 DAYS) NOT for intrathecal or epidural use
Max duration of Ketorolac (Toradol) use?
Max 5 days in adults of all combined delivery methods (IV, IM, PO, nasal)
COX-2 selective agents?
Celecoxib (Celebrex) Diclofenac (Volateren) Meloxicam (Mobic) Etodolac (Lodine) Nabumetone (Relafen)
Brand name of Celecoxib (COX-2 selective agents)?
Celebrex
highest cox 2 selectivity
Contraindicated in sulfa allergy
Brand name of Meloxicam (COX-2 selective agents)?
Mobic
Brand name of Etodolac (COX-2 selective agents)?
Lodine
Brand name of Nabumetone (COX-2 selective agents)?
Relafen
Which COX-2 selective agent has highest COX-2 selectivity and is CI with Sulfonamide allergy?
Celecoxib (Celebrex)
How do u mitigate upset stomach from NSAID use?
Take with food or use enteric coated or buffered forms
Which meds shouldn’t NSAIDs be used with?
Multiple NSAIDs shouldn’t be used together. If taking aspirin + NSAID take aspirin 1 hr before OR 8 hours after
NSAIDs increase levels of lithium and methotrexate
Steroids
Anticoagulant
Antidepressant, including Fluoxetine Paroxetine Sertraline Citalopram Venlafaxine Others
When should NSAIDs be avoided?
If you’ve experienced breathing problems or allergic-type rxns after taking aspirin or other NSAIDs
Effect of NSAIDs on BP?
NSAIDs can raise BP
NSAIDs and photosensitivity?
Limit sun exposure; use broad spectrum sunscreen (blocks both UVA and UVB)
Which opioids are classified as pure opioid receptor agonists?
Codeine
Fentanyl
Hydrocodone
Hydromorphone
Methadone
Morphine
Oxycodone
Oxymorphone
What’s the primary receptor for pain relief?
Mu opioid receptor
While full agonists don’t have a true ceiling effect, how should high doses be used!
Rotated with other opioids to reduce risk of tolerance
Brand name of morphine (long-acting brands)?
MS Contin
Kadian
MorphaBond
Duramorph