Chronic or Acute Visceral, Somatic, Inflammatory, neuropathic
Opioids
Drug that has actions similar to morphine
Opioid receptors
Mu : PEAR physical dependence, euphoria, analgesia, respiratory depression Kappa: SAM sedation, analgesia, miosis
Classification: Pure Opioid Agonist
activate mu and kappa strong and moderate strong agonists ie: percocet/vicodin
Classification: Agonist-antagonist
when given alone produce analgesia BUT when given with another agonist, they have an antagonist effect. Given in L/D
Classification: Opioid antagonist
naloxone (narcan)= antidote reversal agent for overdoses
Drugs: Strong Agonists
morphine, fentanyl, meperidine, hydromorphone (delaudid), methadone, heroin Used for 8/9/10 pain
Drugs: Moderate Agonists
codeine, oxycodone, hydrocodone, propoxyphene
Drugs: Agonist-Antagonist
butophanol, nalbuphine, pentazocine
Morphine (Action/Use/Causes)
Action: mimics action of endorphins Use: moderate to severe pain Causes: analgesia, sedation, euphoria, anxiety reduction, respiratory depression, cough suppressoin, decrese bowel motility
Morphine PK
metabolized by liver excreted by kidnesy large first pass effect with PO meds Onset dependent on route Avoid abrupt discontiuation of opioids
Morphine SE
sedation, orthostatic HYTN, cough supression, urinary retention, biliary colic, constipation, N/V, euphoria, miosis, neurotoxicity, itching, flushing SE start with first does then go away slowly CONSTIPATION DOES NOT STOP TIL DRUG STOPPED
Easing AE of Morphine
Constipation- treat early w/ stool softener, stimulatn laxatives Sedation- eases with time-caffeine or amphetammines N/V- treat w/ promethazine or ondasteron Itching- antihistamine Respiratory depression- naloxone
Cautions when using Opioids
hypersensitviity, head injury, acute asthma, decrease respiratory reserve, sleep apnea, biliary tract disease, chronic users, preg/labor, age extremes, live impairment, IBD, other resp dec drugs
Fentanyl IV (Sublimaze)
100x more potent than morphine IV: conscious sedation / anesthesia rapid onset / short duration HIGH Abuse potential
Fentanyl (Duragesic, Actiq, Fentora)
Duragesic- patch slowly absorbed. Heat acceleartes First patch takes 24hrs to become effective Actiq-losenges on stick Fentora- buccal tablets
Meperidine (demerol)
similar to morphine use is in decline bc frequent dosing needed, interactions, toxic metabolites with long term use Avoid with renal insufficiency Rigers=the shakes when coming out of anesthesia
Methadone
similar to morphine- longer duration and better bioavilabiliy May prolong QT and lead to fatal dysrhythmias
less effective for severe pain kappa agonist, mu antagonist less resp depression, no euphoria can preciptate withdrawl and should not be given to pts who are physically dependent on pure opiods
Tramadol (ultram, ultracet)
Action: weak mu agonists, blocks reuptake of NE and serotonin (not opioid receptors) Minimal potential for dependence, abuse, or respiratory depression (not controlled) SE: rare, sedation, dizziness, headache, dry mouth, constipation, SEIZURES Option for patient who cannot take NSAIDs
NSAIDs - how they work
block production of prostaglandins by inhibiting cyclooxygenase (COX) at the site of injury in the periphery, thus decreasing the formation of mediators of pain in the peripheral nervous system.
gastro effects (PPI may be used in high risk pts) bleeding, renal impairment, salicylism, reye's syndrome, pregnancy, hypersensitivity rxn
Aspirin (ASA) Drug Interactions
anticoagulants: warfarin & heparin- increase risk of bleeding Glucocorticoids: gastric ulcer EtOH: gastric bleeding Ibuprophen: reduce antiplatelet effect by binding site competition ACE-I / ARBs: only when high dose ASA due to renal function impairment Acute poisioning
NonASA 1st Generation
ibuprophen (every 4-6hrs) naproxen (aleve) longer half life
NSAID interactions
lithium warfarin aspirin anti-HTN meds
2nd Generation NSAIDs
Just as effective as traditional NSAIDs at suppressing inflammation and pain Somewhat lower risk for GI side effects Can impair renal function and cause hypertension and edema Increase the risk for MI and stroke
celecoxib (celebrex)
fewer AE than first gen drugs. CV risks= last choice drug for long term mgmt of pain Uses: osteoarthritis, RA, acute pain, dysmenorrhea, FAP
celecoxib (celebrex) AE
dyspepsia, abdominal pain, renal toxicity drug IA: May decrease diuretic effect of furosemide May decrease antihypertensive effect of ACE inhibitors May increase levels of lithium
acetaminophen (tylenol)
analgesic and antipyretic properties- but not anti-inflammatory. drug of choice for kids, fever reduction Does not cause gastric ulceration or suppresses platelet aggregation or cause renal impairment
Acetaminophen OD Tx
acetylcystine (mucomyst)
Acetaminophen toxic dose
max dose in grams is 3.325 in 24hrs
DMARD: methotrexate (rheumatrex)
1st choice for RA works in 3-6wks relatively safe, low cost, effective SE: hepatic fibrosis, bone marrow suppression, ulceration, pneumonitis watch liver, kidney, CBC labs!
etanercept (enbrel)
used for moderate to severe RA AE: infection (serious), injection site rxn, TB, HF, Cancer, Live vacines
Gout
Hyperuricemia- uric acid = excess buildup or impaired excretion. Stages: asymptomatic, acoute gouty attacks, intercritical, tophaceous NSAIDS are first choice
Colchicine
inhibits leukocyte inflitration Used for acute gouty arthritis, prophylaxis SE: GI-N/V/D/pain occurs 80% Precaution in elderly, cardiac, renal, GI, pregnacy
Allopurinol (Zyloprim)
inhibits uric acid production Used for chronic tophaceous gout SE: well tolerated, GI, neuro, cataracts; rarely hypersensitivity Interactions: inhibits hepatic enzymes increasing on warfarin