Pain Management Flashcards
What is Pain?
Generialized physiological and psychological resonse to noixious stimuli
Can warn us that some phsyiologic process has gone awry
Often serves no purpose other than to make a person miserable
Alleviating pain is one of the most basic tasks of any health care professional, including dentists
Pain is complex - two compoents
1) pain as a physiological sensation
2) pain as an emotional and psychological reaction to that sensation
Note: Of these, psychological component is the most important, bc it represents pain as “suffering”
Aspirin, ibuprofen, NSAIDs and related agents
Inhibitors of prostaglandin synthesis (COX-1 and COX-2)
Alleviate pain by acting at nerve endings and in the CNS
Anti-inflammatory effects may contribute to pain relief
Can by very effective for mild-moderate dental pain
GI side effects (irritaion, bleeding, etc. are huge problem)
Also, potential for serious CV side effects (hypertension, MI, stroke etc.) with chronic use.
Acetaminophen
Inhibits prostaglandin synthesis in nerve endings and CNS, but not in the periphery
Alleviates pain by acting at nerve endings and in the CNS (exact mechanism of action is still not clear)
No anti-inflammatory activity
No tendency to cause GI irritation
Potential for hepatotoxicity at high doses
Selective COX-2 inhibitor
Celocoxib (Celebrix) - only one still on the market
Fewer GI side effects than traditional non-selective COX inhibitors
Adverse cardiovascular effects (strokes and MI’s resulted in withdrawal of other COX-2 inhibitors from the market a few years ago.
Local Anesthetics (lidocaine and related agents)
Block sodium channels in nerve endings and axons and stop generation and conduction of action potentials.
Small, unmylenated pain fibers are most sensitive but other neurons can be affected.
Powerful pain relief w/local, retional and nerve block techniques.
Invasive procedures and may affect motor function and sensory modalities.
Very imp for pain management during dental procedures
Opioids
Most effective drugs for most types of severe pain
They are under-utilized bc of illegal issues and the fear of addiction
Dependence does not equal Addiction
Drug dependence is a physiologic state resulting from chronic exposure to a drug
Drug addiction is a pattern of behavior in which the use of a drug assumes a central role in a person’s life
The vast majority of patients who take opioids for valid medical uses do not become “addicts”
Opioids - Mechanism of Action (imp to know)
Acts as agonists at receptors for endorphins and enkephalins
They act in the limbic system to uncouple the emotional component of pain from the physical sensation
They can also inhibit the transmission of pain impulses in the spinal cord
Drugs acting on the mu type opioid receptor are the most powerful analgesics but also have the greatest abuse potential
Opioid receptors - mu, kappa and delta
mu receptors - primarily in the brainstem, spinal cord, and limbic areas - mediate supraspinal analgesia, some spinal analgesia, sedation, respiratory depression, euphoria and dependence - *most powerful pain relievers*
kappa receptors - mainly in the brainstem and spinal cord, and to a lesser exten, the limbic system. They are thought to mediate some spinal analgesia, some supraspinal analgesia, meiosis, sedation, and dysphoria.
delta receptors - brainstem and limbic system, and mediate dysphoria and hallucinations
Strong Analgesics (mu agonists)
morphine
codeine
fentanyl (sublimaze)
heroin
hydrocodone (vicodin, lortab, others)
hydromorphone (Dilaudid)
meperidine (Demerol)
methadone (Dolophine)
oxycodone (Percodan, Percocet, OxyContin)
Partial Agonists and Mixed Agonist/Antagonist Analgesics
pentazocine (Talwin)
Buprenorphine (buprenex, subutrex, suboxone)
butorphanol (stadol)
tramadol (Ultram) - mostly used for mild to mod pain
Schedule 1
no medical benegit but high abuse potential - can’t prescribe these
Schedule 2
requires a paper prescription and only filled for 30 days
vicodin and hydrocodone
Schedule 3
phone in or electronic prescription and can be refilled upto 6 times
Corticosteroids, Disease Modifying Antirheumatic Drugs (DMARDS) and Immunomodulators
act on various components of the immune system; they are usefyl in the treatment of inflammatory and autoimmune disorders (e.g. rheumatoid arthritis and lupus erythematosis). Corticosteroids can have powerful analgesic effects.
Muscle relaxants
Relaxing skeletal muscle, they can break muscle spasms and are useful in the management of low back pain
Antidepressants (*amitriptyline)
They can alleviate symptoms of depression that commonly occur in patients with chromic pain and they can enhance the analgesic effects of opioids. In addition, some are beneficial in the treatment of neurogenic pain.
Anticonvulsants (carbamazepine, gabapentin (neurontin) and pregabalin (lyrica))
useful in the management of various types of neurogenic pain
Drug selection - general principles
Proper assessment of patient - characterize the type and level of pain
If possible, treat or remove the cause of pain
select drugs that are appropriate for the type and level of pain
consider the health status of the pt in relation to the side effects and potential toxicites of the medications
use medications at the proper dosage levels. main pts w/ severe pain are under medicated
consider the legal issues related to the use of opioid analgesics
Mild pain
acetaminophen
aspirin
ibuprofen, ketoprofen, naproxen
Moderate pain
oral NSAIDs (especially for arthritis, musculoskeletal, postsurgical and dental pain)
intermediate potency opioids (codeine, hydrocodone, etc) usually in combination w/ acetaminophen or aspirin. Mixed agonist antagonist opioids such as tramadol would also be appropriate
Severe Pain
strong opioids (morphine, oxycodone, hydromorphone, fentanyl, methodine, etc.) either alone or in combination w/ other agents. Keep in mind that patients w/ severe pain may require higher than normal doses of opioids
NSAIDs
adjuvant drugs such as antidepressants, anticonvulsants
