6 - Opioid Analgesics Flashcards
Opiod Agonists attach to what receptors? (3)
Mu
Kappa
Delta
Opiod Agonists: Natural Opium Alkaloids (3)
Morphone
Codeine
Noscapine
Opiod Agonists: Semi-synthetic Opioids (4)
Heroin
Pholcodeine
Hydromorphone
Oxymorphone
Opiod Agonists: Synthetic Opioids (First 4)
Meperidine
Tramadol
Methadone
Dextropropoxyphene
Opioid Agonists: Synthetic Opioids - Ultra Short Acting, Potent, and used IV (4)
Fentanil
Alfentanyl
Sufentanil
Remifentanil
Opioid Agonists: Mixed Opiod Agonist-Antagonists (4)
Pentazocine
Buprenorphine
Nalbuphine
Butorphanol
Opioid Agonists: Pure Opioid ANTAGONISTS (3)
Nalaxone
Naltrexone
Nalmefene
Opioid Receptors: Mu functions (4)
Supraspinal and spinal analgesia in CNS
Sedation and euphoria
Inhibition of respiration
Slowed GI transit (periphery)
Opioid Receptors: Kappa functions (3)
Supraspinal and spinal analgeisa
Psychotomimetic/dysphoria effects
Slowed GI transit
Opioid Receptors: Delta functions 1)
Supraspinal and spinal analgesia
Endogenous Opioid Peptides (3)
Endorphins
Enkephalins
Dynorphins
Opioids Effects: CNS - Analgesia (1)
Reduce both sensory and affective components of pain
Opioids Effects: CNS - Euphoria (1)
Pleasant floating sensation with lessened anxiety and distress
Opioids Effects: CNS - Sedation (1)
Drowsiness and clouding of mentation
Opioids can respond to what types of pain (3)
Dull, aching pain
Sensory (Feeling pain)
Emotional response to pain
Opioids Effects: Respiratory depression (1)
Inhibit brain stem respiratory mechanisms (no longer respond to CO2) –> Resp rate 3-4 minutes
Opioids Effects: Cough suppression (1)
Suppress cough reflex
Opioids Effects: Miosis (1)
Mediated by parasympathetic pathways (M3 receptor)
Opioids Effects: Nausea and Vomiting (1)
Activate the brainstem chemoreceptor trigger zone (CTZ) to produce nausea and vomiting AND due to delayed gastric emptying
Opioids Effects: Cardiovascular System (1) and Morphine Actions
Peripheral arterial and venous dilation: central depression of vasomotor-stabilizing mechanisms and release of histamine
Morphine has negative ionotropic and chronotopic action on heart
Opioids Effects: Cardiovascular System - Meperidine (2)
Tachycardia
Anti-cholinergic (Atropine-like) action
Opioids Effects: GI Tract (1)
Motility may decrease, but tone (persistent contraction) may INCREASE (constipation)
Opioids Effects: Biliary Tract (3)
Contract biliary smooth muscle
The sphincter of Oddi may constrict –> reflux of bilary and pancreatic secretions –> elevated plasma amylase and lipase levels
Meperidine given for acute biliary colic (atropine like action), nitroglycerin, or atropine
Clinical Use of Opioids: Analgesia (3)
Severe, constant pain (dull aching) with high intrinsic activity opioids (morphine, heroin, methadone)
Cancer and other terminal illnesses (trauma, gunshot wound, post-operative)
Severe pain of renal and bililary colic
Clinical Use of Opioids: Acute Pulmonary Edema from LVH - Drug (1) and Facts (3)
Morphine used
Reduced cardiac preload
Reduced afterload
Can also give a diuretic (furosemide)
Clinical Use of Opioids: Dry Cough Drugs in Low Doses (4)
Codiene
Pholcodiene
Noscapine
Dextromethorphan
Clinical Use of Opioids: Diarrhea Drugs (2)
Diphenoxylate (small amount of atropine added to prevent misuse)
Loperamide (doesn’t cross BBB)
Clinical Use of Opioids: Applications in Anesthesia (Ultra Short Acting Opiods) (3)
Premedicant drugs to prep for surgery
Intraoperatively as adjuncts to other anesthetic agents
High doses as a primary component (e.g. fentanyl)
Alternative Routes of Administration: Rectal Suppositories (2)
Morphone
Hydromorphone
Alternative Routes of Administration: Transdermal Patch (1)
Fentanyl (sustained plasma levels, all day)
Alternative Routes of Administration: Intrnasal (1)
Buturphanol (avoids first pass metabolism)
Alternative Routes of Administration: Buccal Transmucosal (1)
Fentanyl citrate lozenge or “lollipop”
Alternative Routes of Administration: Patient-Controlled Analgesia (PCA) (1)
Parenteral (usually IV) infusion device that delivers a preprogrammed dose of the desired opiod analgesic
Opioids Toxicity: Tolerance (3)
Develops 2–3 weeks of frequent exposure to ordinary therapeutic doses
Marked tolerance may develop to the analgesic, sedating, and respiratory depressant effects
Can give calcium channel blockers to delay tolerance
Opioids Toxicity: Physical Dependence - Withdrawal/Abstinence Syndrome (9)
Dysphoria initially
Rhinorrhea
Lacrimation
Yawning
Chills
Gooseflesh
Hyperventilation
Hyperthermia
Mydriasis
Opioids Toxicity: Psychological Dependence (1)
To derive pleasure
Opioids Agonists: Methadone Defined (4)
Extended duration of action
Persistent effects with repeated administration
Can also block NMDA receptors
Slower duration of action so slower dependence, this less intense withdrawal
Opioids Agonists: Methadone Uses (3)
Treatment of opioid abstinence syndromes
Treatment of heroin users
Relief of chronic pain
Opioids With Mixed Receptor Actions: Nalbuphine (3)
Strong Kappa receptor agonist
Mu receptor ANTAGONIST
Will see acute withdrawal
Opioids With Mixed Receptor Actions: Buprenorphine (4)
Potent and long-acting partial receptor µ agonist.
Sublingual route is preferred to avoid significant first-pass effect.
Long duration of action; can be abused (similar to methadone)
Detoxification and maintenance of heroin abusers.
Opioids With Mixed Receptor Actions: Suboxone is Buprenorphine and?
Naloxone
Opioids With Mixed Receptor Actions: Butorphanol (1)
Predominantly KAPPA agonist that causes dysphoria (psychotomimetic actions)
Opioids With Mixed Receptor Actions: Pentazocine (2)
Kappa AGONIST with MU ANTAGONIST or
Partial agonist properties
Opioids With Mixed Receptor Actions: Tramadol (1)
Blockade of serotonin reuptake
Contraindications and Cautions: Use of pure agonists with weak PARTIAL agonists (1)
Cancel the actions of morphine –> reduced analgesia/acute withdrawal reaction
Contraindications and Cautions: Use in patients with head injuries (1)
Increases intracranial pressure from respiratory depression
Contraindications and Cautions: Use DURING pregnancy (1)
Fetus can get addicted
Contraindications and Cautions: Use in patients with impaired pulmonary function (1)
Causes respiratory depression
Contraindications and Cautions: Use in patients with impaired hepatic or renal function (1)
Opioids are metabolized in liver and excreted through kidney
Opioid Antagonists (3)
Naloxone
Naltrexone
Nalmefene
Opioid Antagonists: Naloxone Use (2)
Acure Opioid Overdose (Resp, Constricted pupils, and Coma)
Low-dose: Treatment of adverse effects that are commonly associated with IV or epidural opioids that relieve itching, nausea and vomiting while sparing use of analgesia
Opioid Antagonists: Naltrexone Use (1)
Maintenance drug for alcohol and nicotine addicts
