Pain Flashcards
Stepwise approach to pain management
- Mild pain can be self treated at the pharmacy and usually responds to acetaminophen or an NSAID
- Moderate pain is often treated with a combination products such as hydrocodone oxycodone which acetaminophen
- Severe pain may require opioids although neuropathic pain may respond adequately to non-opioids such as duloxetine or pregabalin
- Neuropathic pain may respond to an antidepressant such as amitriptyline duloxetine and/or an anticonvulsant such as pregabalin
general notes
All patients on opioid should have constipation prophylaxis and should be monitored for sedation as this is the most important predictor of respiratory depression
Acetaminophen
MOA: inhibits the synthesis of prostaglandins in the CNS and peripherally blocks pain generation
Products:
- acetaminophen (Tylenol) plus hydrocodone is (Vicodin, Norco, Lortab)
- Plus codeine (Tylenol number 2, 3 and 4
- Plus oxycodone (Percocet, Endocet)
- Plus tramadol (Ultracet)
- IV Tylenol (ofirmev)-used inpatient to offset higher opioid doses
Dosing:
1. Children: 10 to 15 mg per kilogram every 4 to 6 hours for a max of five doses per day
Blackbox warning: severe hepatotoxicity, potentially requiring liver transplant or resulting in death; hepatotoxicity is usually associated with excessive acetaminophen intake greater than 4 g per day
Side effects: hepatotoxicity (avoid concomitant use with isoniazid, barbiturates, alcohol, zidovudine)
Notes: drug of choice for pain ainpregnancy; antidote is in N-acetylcysteine (restores intracellular glutathione) does that 140 mg per kilogram loading followed by 70 mg per kilogram of 17 doses
Aspirin/NSAID
MOA: block the activity of thromboxane and prostaglandins
COX-1 inhibition increases bleeding risk
COX-2 inhibition increases cardiovascular risk
Blackbox warning:
- Cardiovascular: NSAIDs may cause increased risk of serious CV events (may increase with duration)
- GI: increased risk of serious G.I. events including bleeding, ulceration, and perforation of the stomach or intestines (elderly, those with a history of G.I. bleed, patients taking corticosteroids, and those taking concurrent SSRIs or SNRIs are at greater risk
- CABG: contra indicated in CABG surgery
Aspirin-acetylsalicylic acid
Bayer, Bayer advanced aspirin, Ascriptin, Bufferin, Ectorin, Excedrin
Avoid in: elderly, children, previous bleed, chronic or high-dose use, commitment anticoagulants, smoking, Renal issues
Side effects: dyspepsia, heartburn, nausea take with food to decrease irritation and nausea, blood-pressure may increase from G.I. irritation and bleeding, renal dysfunction, CNS effects, severe skin rash (stop drug if this occurs)
Notes: stop all NSAIDs at least a week prior to elective surgery, overdose can manifest with tinnitus
Salsalate
Similar to aspirin, lower G.I. risk, can cause tinnitus with overdose
Ibuprofen (Motrin, Advil)
Max dose of 1.2 g per day (OTC)
Max dose of 3.2 g per day (Rx)
Considerations are similar to aspirin
Naproxen Na+
Vimovo (Naproxen-esomeprazole): combo used to protect the gut
Dosing: all given twice a day
Relatively lower cardiac risk than some of the other NSAIDs
Diclofenac (cataflam, Voltaren XR, Arthrotec (misoprostol component for GI protection), Voltaren gel, Flector patch)
Nonselective and NSAID
DOSING: B.I.D.
BLACKBOX WARNING: SAME AS OTHER NSAIDS PLUS ARTHROTEC NOT TO BE USED IN WOMEN OF CHILDBEARING POTENTIAL (due to misoprostol component which can increase uterine contractions)
Indomethacin (Indocin IR, CR)
Approved for gout
High risk for CNS side effects (avoid psych conditions) and G.I. toxicity
Piroxicam (feldene)
High risk for G.I. toxicity and severe skin reactions including Steven Johnson syndrome and TEN
use if other NSAIDs fail and may need agent to protect gut such as a PPI or misoprostol
Ketorolac (Toradol)
Nonselective NSAID
Can cause severe adverse events including G.I. bleeding and perforation, post op bleeding, acute renal failure, liver failure and anaphylactic shock
For short term moderate to severe acute pain only use a max of five days supply in adults (almost always postop and never pre-op)
COX-2 selective drugs
Celecoxib (Celebrex): Cox-2 selectivity
Meloxicam (Mobic): some cox-2 selectivity
Etodolac (Lodine): some Cox-2 selectivity
Nabumetone (Relafen): some Cox-2 selectivity
Celecoxib or Celebrex
Indications: OA, RA, juvenile RA, acute pain, primary dysmenorrhea, alkalizing spondylitis
Notes: highest COX-2 selectivity, pregnancy category C prior to 30 weeks gestation (category D beyond 30 weeks gestation)
Contraindications: sulfonamide allergy
Considerations are similar to all other NSAIDs
NSAID drug interactions
- Additive bleeding risk: aspirin, clopidogrel or Plavix, prasugrel or Effient, ticagrelor or brilinta, dipyridamole or Persantine, warfarin, dabigatran, Rivaroxaban, ginkgo biloba and others
- SSRIS: fluoxetine, paroxetine, sertraline, citalopram, Escitalopram, venlafaxine
Opioids
Codeine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, and oxymorphone
Pure opioid receptor agonist at the mu receptor
No ceiling affect therefore they have no limitation to how much pain relief they can offer, however opioids at high doses should be rotated with other opioids to reduce the risk tolerance