Module 3, Section 6 Management of Pain PDF

 Management of Pain Introduction to Pain Management 2 categories of...

 Management of Pain Introduction to Pain Management 2 categories of drugs that treat > - pain : ① Opod analgesics : substances derived from spiod and act on opioid receptors In the to releive /ex morphine) brain pain. ② Non-opiod analgesics of apioid independantly to substances acting receptors : releive pain (ex. ibuprofen Non-Opiod Analgesic Drugs prin as tylen o > - includes over the counter drugs (acetylsalicylic acid and acetaminophen) and some require prescription > - they alleviate pain with low potential for misuse or withdrawl , but there are still adverse effects which can be serious and even fatal they all > - act via the same mechanism : -I or 2 (COX) all act by cyclooxygenase reducing amount of prostaglanding > - Inhibiting enzyme , el prostaglandins = endogenous substances that S to sensitize nerve endings mediators of pain reduce , fever and inhibit propagation Non-Steroidal Anti-Infammatory Drugs (NSAIDs of inflammation largest class of non-opioid analgesicdrugs Cox-1 protective > - = they have analgesic and andi-inflammatory efeis cox-2 Inflammatory > - antipyretic = , It pain) Id fever (asprin) , Ib profen ladvil) and naproxen most common-acetylsalicylic acid > - mechanism of action Inhibit prostaglandin synthesis > - = CYP450 kidneys > - most NSAIDs are well absorbed highly metabolized by enzymes excreted via : , ,  Adverse Effecte of NSAIDS CNS- headache ears) tinnitus (ringing dizziness · in , , Pulmonary w/ · - higher risk of allergic run for those asthma · Cardiovascular - Fluid retention , edema hypertention , · Hepatic - liver function abnormalities , liver failureCravel - Renal-renal failure insufficiency , renal · Gastrointestinal abdominal pain , ulcers /ravel nausea , vomiting - , · Slein-rashes Non-Selective NSAIDS 1) Acetylsalicylic Acid (asprin) used for fever - can be mild to mederate pain for ↳ additional stroke use prevention and myocardial infarcts = ↳ be they platelet and hence clot formation can inhibit mmmu aggregation num ↳ key adverse effect = associated wh developement of Reyee Syndrome when given 2) Ibuprofen ladvil) - more effective than ASA in a number of conditions ↳ as it's efficacious anti-inflammatory , probably one of the most over-the-counter between blood vessels agents on the market opening major in heart ↑ -s clinical use = can be used to close patent ductas arteriosus (heart defect preterm infante and for in post-surgical dental pain ↳ mechanism of action Inhibition of COX-1 & but be reversible Cox-2 may = enzymes , more effective CoX-1. inhibiting in 3) Naproxen > most - recent addition to over-the-counter group of analegies > - clinical use = rheuatologic indications /such as neumatoid arthrits) as an orthalmic solution leye drops) and topical preparation - mechanism of action = reversible Inhibition of Cox-1 & Cox-2 enzyme 4) Diclofenac - only availible wl prescription > - clinical use = ophthalmic preparation for prevention of ophthalmic infammation & as topical get for solar Keratosis (skin condition from Sun damage) S rectal for 3 suppository preemptive analgesia and postop Kaused -mechanism of action and relatively non-selective Inhibitor of Cox-1 Cox- = Selective NSAIDs > - only Inhibit Cox-2 enzymes (synthesize Inflammatory prostaglanding > - Ideal because inhibition of protective prostaglanding /synthesized by cox-1) contribute to adverse effects of non-selective NSAIDs Cox-2-selective inhibitors have analgesic antipyretic and anti-inflammatory > - , properties similar to non-selective cox inhibitors , however , the gastrointestinal adverse effects are decreased by about 12 · Celecoxib - 10-201 more selective for COX-2 than for COX-1 ↳ clinical use = releives pain and inflammation caused by arthritic- conditions such as osteoarthritis and & for rheumatoid arthritis post-surgical pain · Meloxicam ↳ also preferentially inhibits cox-2 , but not to same extent as Gelecoxib > - Clinical use = releives pain and Infammation caused by conditions turitic * other COX-2 inhibitors have 4 Incidence of cardiovascular thrombotic events such as heart , attack or stroke  Other Non-prescription Drugs Acetaminophen (Tylenol/paracetamol : acetaminophen NSAID (analgesic and antipyretic but not anti inflammatory( > - most used widely over-the-counter analgesic > - mechanism of prostaglandin formation (10X-1 & Cox-2) > - action = Inhibiton of is responsible for analgesic and antipyretic effect febrile therapeutic drug of G1 Irritation and > - uses = choice when ASA causes conditions (acetaminophen not associated w/ Reyes Syndrome), are 120 tablets) during pregnancy - S-loy > - adverse effects can lead to liver (in overdose/large doses overtime/individuals injury = w/ alcohol use disorder or liver disease/condition (cirrhosis) ↳ related to metabolism and depletion of glutathione (because it's - used do detoxify NAPQI (toxic intermediate produced in metabolism of acctaminophen)) ↳ causes liver damage ↳ treatment = antidote N-acetylcysteine ↳ /source of glutathionel decreases amount of NAPQI Opiod Analgesics > - drugs obtained from the opium alleviate pain for millenia > - poppy morphine and comprimise and respectively codeine about 10 % 0 5%. of crude exudate , ↳ morphine = one of the most useful drags In pharmacology but it's known for causing addiction and withdrawl opiate from opium (ex morphine and codeine any drug derived :. opiod : any natural or synthetic substance that exerts actions on the body similar to those induced by morphine & are antagonized by naloxone Includes ↳ (ie morphinal opiates structurally substances to :. similar , morphine (ei Heroin) different from morphine lie.. , structurally methadone) , endogenous brain peptide that exert analgesic actions Die endorphins. Opiod Receptore > - In CNS & PNS and other tissues such G1 tract , where causes constipation , as binding > - G-coupled receptors and messenger systems to cause effect activating an , several 3 will be discussed K S types > - , : M , ,  · Mu (M) spiod receptors (MOP) > - present in all structures of brain & spiral cord (inability pain) - activation feel = mediate analgesia to , morphine-mediated depression of respiration In brain stem ↳ difficult to obtain drugs separating the 2 responses ↳ also involved in compulsive behaviour ↳ beta-endorphin 1 and 2 endogenous ligands = & endorphin Kappa (k) Opiod Receptors (KOP) : · ↳ involved in analgesia dysphoria , , and miosis (pinpoint pupils) > - mixed opiod agenists/antagonists (ex · pentazocine) act predominately on these receptors ↳ endogenous ligands dynorphins = , endorphins have some activity at these receptors · Delta (8) Opioid Receptors (DOP) - involved at level of spinal cord and in analgesia brain ↳ modulate the may also emotional opioids response to ↳ endogenous ligands enkephaling = Opiods and Pain morphine and other opiods > - will block pain pathways in the spindl cord and in the brain ↳ of effect is exerted through activation primarily MoP receptors > - different ways opioids inhibit the pain Impulse : 1 Reduced release of chemical transmitters mobilized by pain impulse Activation of decsending Inhibitory to block pain E. pathway input. 3 Blockade of of these transmitters postsynaptic effect. 4 Reduced response(emotional reaction) to pain limbic of brain by acting on area  Short Term Effects of Opioids > - analgesia (d pain (perception + reaction) - no limit to the pain that can be releived Cresp depress limiting = factor motility (constipation > - decreased as > - Sedation endocrine effects (d release of hormone that from hypothalamus > - regulate release of sex hormone suppression of I libido men ↳ cough > - centre cause in menstrual irregularities in women (constriction of pupils point > - miosis - pin > - respiratory depression (typical cause of deathIn overdose > - heart rate irregularity + thermoregulation (body temp d skin , is old and clamy Therapeutic Uses of Opioid Drugs · Relief of severe pain Treatment of diarrhea /diphenoxylate : (Lomofil) usel - doesn't cause opied use disordent · Suppression of cough (they are effective but there are better alternatives ( · Treatment of opiod use disorder (Buprenorphine/naloxone and methadone Opioid Use Disorder > - Tolerance , withdrawl and addiction develops to all opioid anlagestic > - problematic > - Tolerance doesn't develop to constriction of pupils or constipation > - Cross-tolerance occurs between all opioid analgesics (act on same receptor Neonatal Opioid Overdose brug Withdrawal and and if fetus clinically significant Opioid disorder impairment distress to the also pregnant > - use can cause or user is , affected Neonatal brug Withdrawal · > - individual wh opioid disorder face I of an use who is pregnant an risk and low infant premature delivery birth weight > - of birth , the infant undergoes abrupt termination of drug supply , resulting in a withdrawal reaction Cirritability , sleep disturbance , poor - feeding , occasional last weeks seizures may - months  · Opioid Overdose ↳ medical emergency of profound respiratory depression (cause deatn) > - overdose causes > - treatment = opioid antagonists (naloxone) and Support of respiration and other vital functions Treatment of Opioid Use Disorder preferred first line treatment = buprenorphine/naloxone (M) buprenorphine-long-acting that acts ↳ synthetic opioid as a partial mu receptor agonist ↳ half-life = 24-42 his ↳ provides enough agonist I activity to prevent withdrawal symptome , while having euphoria and sedation compared to full agonists In ↳ Canada , buprenorphine is availible in combination w/ naloxone (opioid antagonist ↳ taken it's not absorbed significant degree to first when orally , to due pass effect, In comparison to intravenous ingation ccarses withdrawal symptoms) : preventing misuse of the drug (deters patients from trying to ingat/snort (misuse second line treatment = methadone synthetic opioid effective administration w/ half life following oral long ↳ ↳ misuse is much lower than other opioids (ie morphine. , heroin treatment of psychosocial supports counseling & concurrent physical and mental heath issues should be > - , considered to optimize recovery