1 / 60

PAIN MANAGEMENT Opioids, NSAIDs, Migraine drugs

PAIN MANAGEMENT Opioids, NSAIDs, Migraine drugs. NURS 203, Pharmacology I Dr. Nolan. PAIN. Most common complaint leading people to seek healthcare Can be acute or chronic Acute – less than ~3 months duration Chronic – 3 months or longer. TYPES OF PAIN. ACUTE

oro
Download Presentation

PAIN MANAGEMENT Opioids, NSAIDs, Migraine drugs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PAIN MANAGEMENTOpioids, NSAIDs, Migraine drugs NURS 203, Pharmacology I Dr. Nolan

  2. PAIN • Most common complaint leading people to seek healthcare • Can be acute or chronic • Acute – less than ~3 months duration • Chronic – 3 months or longer

  3. TYPES OF PAIN • ACUTE • CHRONIC (longer than 3 months) • CANCER PAIN • SOMATIC PAIN • VISCERAL PAIN • NEUROPATHIC PAIN

  4. Types of Pain • Cancer • Can be acute or chronic • Somatic • Localized to a certain area (bone, muscle, skin…) • Can be acute (injury) or chronic (arthritis) • Visceral • Not localized, harder to define • Nociceptors in internal organs are stimulated (hepatitis, pancreatitis…) • Dull, aching, cramping, deep pain

  5. Types of Pain • Neuropathic • Perpheral pain receptors or nerves, damaged or dysfunctional • Excessive excitability in these areas, leading to exaggerated pain response • Diabetic neuropathy, herpes zoster (Shingles, post-herpetic neuralgia) • Not as responsive to normal analgesics

  6. Pain Physiology • Tissue damage stimulates peripheral pain receptors – nociceptors • Signal transmitted to spinal cord (ascending pathway) – hypothalamus – cerebral cortex • A-delta fibers : acute, “fast” pain • C fibers : slow, poorly localized pain • Descending pathway – inhibitory pathway, includes endogenous opioids, norepinephrine and serotonin to suppress nociceptive transmission of pain impulse via substance P

  7. Neural pathways for pain.

  8. Pain Treatment - Analgesics • Opioids • Non Opioids • NSAIDs • Tramadol • Acetaminophen • Antidepressants, antiepileptics • Neuropathic pain • CNS vasoconstrictors • Migraine pain

  9. Review Question • Which of the following drugs does not have a “ceiling” dose? • A) acetaminophen • B) ibuprofen • C) aspirin • D) morphine • E) all of the above have ceiling doses that should not be exceeded

  10. Opioid Analgesics – general characteristics • Relieve moderate to severe pain by inhibiting pain signal transmission from periphery to brain. • Well absorbed with PO, IM, SQ administration. • Metabolizedin liver, metabolites excretedin urine. • Liver or Renal impairment can interfere with metabolism or excretion.

  11. Opioids - widespread pharmacological effects • CNS • Analgesia • CNS depression • Respiratory depression • Pupil constriction • GI • Slowsmotility • Constipation • N/V • Bowel and Biliary spasm

  12. Opioids • Potent analgesics for moderate to severe pain • Acute and chronic pain • best for nociceptive pain • Not generally effective for non-nociceptive pain (neuropathic) • Serious side effects • No ceiling dose • chronic use universally leads to tolerance, physical dependence, may lead to addiction • tolerance leads to high doses in patients treated long term with opioids that could kill opioid naïve patients

  13. Opioids – Mechanism of Action • Stimulate Mu and Kappa receptors • Mu • Analgesia, ↓ gastric motility, sedation, respiratory depression, euphoria, physical dependence • Kappa • Analgesia, ↓ gastric motility, sedation • Mixed agonist/antagonists stimulate one, antagonize the other • Antagonists antagonize both (block opioids from binding to receptor or displace) • naloxone

  14. Opioids – Mechanism of Action • Binding to Mu and Kappa receptors slows the transmission of pain impulses between cells in the periphery, spine, and brain • Stimulating Mu and Kappa receptors activates the endogenous analgesia system • Endorphins, etc. act on receptors same as exogenous (narcotic) agents

  15. Opioids –Effects • Analgesia • Sedation, CNS depression (life threatening) • Respiratory depression (life threatening) • Constipation • Euphoria • Nausea/vomiting • Dependence • Tolerance • Miosis

  16. Opioids - widespread pharmacological effects • CNS • Analgesia • CNS depression • Respiratory depression • miosis • GI • Slowsmotility • Constipation • N/V • Bowel and Biliary spasm

  17. Opioids - Pharmacokinetics • Well absorbed orally, and via SQ, IM, and IV • Metabolized hepatically • Excreted via urine • Liver or renal disease can inhibit clearance or efficacy • T1/2 can range from minutes (IV) to days (fentanyl patch)

  18. Opioids – indications • Before, during, after surgery • To provide pain relief, sedation, ↓anxiety • Acute and chronic pain control, outpatient • there is limited data on the safety and efficacy of treating chronic pain with opioids • significant safety concerns • Pain/anxiety reduction for various procedures

  19. Opioids – contraindications/cautions • Respiratory depression, lung disease • Hepatic/renal dysfunction • Increased intracranial pressure • Allergy (true allergy)

  20. Morphine • Opioid agonist (primarily acts on Mu receptor) • Named after the Greek God of dreams, Morpheus • Prototype opioid analgesic • DEA Schedule II (DEA CII) • Given PO, SL, PR, TD, SC, IM, IV, IT, PCA pump

  21. Morphine • Maximal analgesia and resp depression within: • 10-20 min IV • 30 min IM • 60-90 min SC • 60 min orally (IR). ER forms are QD or BID • Duration is 5-7 hours (PO ER ~ 12-24 hours)

  22. Morphine - Pharmacokinetics • T1/2 is about 7 hours • Metabolites accumulate in pts with renal/hepatic dysfunction, must reduce dose • 30% bound to plasma proteins, extensive first pass metabolism • So PO doses considerably higher than Inj doses

  23. Morphine – Some specific uses • moderate to severe pain • procedure related anxiety/pain • MI related pain • Pulmonary edema • why?

  24. Morphine – Some cautions • head trauma – increased intracranial pressure • long acting agents with short acting procedures • respiratory depression can manifest after procedure

  25. Morphine – Side Effects • Profound sedation/CNS depression • Constipation, N/V • at least 41% incidence of constipation with chronic opioids • in 2000 study, 95% of patients interviewed by nurses in a hospital oncology unit reported constipation as the major side effect of their pain therapy • Resp depression, decreased breath sounds • Encourage deep breathing, coughing • Hypotension • Physical dependence • Paradoxical CMS stimulation and insomnia

  26. Morphine – availability • 24 hour controlled release • Kadian, Avinza • BID-TID controlled release • MS Contin, Oramorph • Q4-6h immediate release • MSIR • Liquid • MS oral solution, 10mg/5ml, 20mg/5ml, 100mg/5ml (concentrated) • Embeda (morphine/naltrexone) • naltrexone inactive unless crushed

  27. Morphine administration • Embeda, Kadian, Avinza caps can be opened and sprinkled immed. prior to oral admin. • DON’T chew the pellets! • IM vs. SQ for repeated doses to reduce tissue irritation • Don’t administer IV too quickly to avoid excessive sedation and RR depression • 2.5mg to 15mg over 5 minutes • PO vs parenteral doses • TYPICAL DOSE: • ORAL 30mg Q4h • IV/IM 5-10mg q4h

  28. Morphine important points • Breakthrough pain • Continuous infusion or SR forms will need short acting bolus or tablets for breakthrough pain • HIGH ALERT • periodically monitor RR, BP • caution if RR<10 • Placebo effect • Explain the therapeutic effect to the patient • Suggestions of efficacy are often very effective in increasing analgesia • Don’t let pain get severe • opioids are more effective in maintaining analgesia if pain doesn’t become severe

  29. Morphine important points • Watch the concentration • DON’T confuse 20mg/5mL with 20mg/mL • 20mg/mL liquid should be given via oral syringe • Bowel function • Bowel habits should be documented before beginning opioid therapy • assess periodically, daily if constipation. • Administer docusate and stimulant laxatives (senna, bisacodyl) on a regular basis if tx exceeds a few days • bulk forming may lead to impaction, especially in palliative care • watch for confounding drugs (anticholinergics) and dehydration

  30. Morphine important points • Don’t crush, break, chew, or dissolve sustained release (SR), controlled release (CR), or extended release (ER) dosage forms! • rapid release of entire day’s dose an result in opioid overdose

  31. Fentanyl • CII, Potent opioid agonist • Available as IV, patch, SL tablet & film • IM/IV • Used pre, during, post surgery • analgesic supplement for general anesthesia • Same cautions apply as for morphine • head trauma • profound sedation, RR depression… • Dosed in micrograms (mcg), caution!

  32. Fentanyl • Patch • Duragesic (fentanyl patch) for chronic pain in opioid tolerant pts • NOT for post-op pain, intermittent pain, or short term pain • 92% absorbed through skin • Dosed every 72 hours • take about 20 hours for the serum conc to reach one half after removal of patch • steady state and maximal analgesia reached by end of second patch application • Comes as mcg/hr patches (eg. 50mcg/hr)

  33. Fentanyl • transmucosal • short acting, for breakthrough cancer pain in opioid tolerant pts (Actiq, Fentora) • opioid tolerant means equivalent of 60mg/day morphine • Buccal film • about half absorbed through muscoa, the other half swallowed • swallowed fentanyl is ~20% bioavailable • Transmucosaltablets, lozenge (lollipop), and nasal spray also available • these products are NOT interchangeable on a per dose basis • Exercise extreme caution if children in the household! • rapidly fatal • watch for partially used discarded “pops”

  34. Other opioids • Embeda (morphine/naltrexone) • intended use is to prevent abuse • combines microencapsulated naltrexone core to morphine sulfate beads inside capsule • only crushing, chewing, or dissolving will release the naltrexone to attenuate the euphoric effects of the morphine • very expensive compared to morphine sulfate

  35. Other opioids • Oxycodone (OxyContin) – CII • IR and CR dosage forms • “Oxy’s” became a common street drug, selling for over $100 per tablet • Can be combined with APAP (Percocet) or ASA (Percodan) • Hydrocodone (Vicodin) – CIII • Similar to codeine in use and efficacy • Combined with APAP

  36. Other opioids • Hydromorphone (Dilaudid, Exalgo) - CII • PO, PR, SC, IM, IV • More potent than morphine, ↑efficacy PO vs morphine • Oxymorphone (Opana) • Derivative of morphine, similar characteristics • Methadone (Dolophine) • Synthetic form of morphine • longer DOA (T1/2 30h +)

  37. Other opioids • Propoxyphene (Darvon, Darvocet) - CIV • Least effective opioid out there • No more effective than APAP, but causes sedation and resp depression like other opiates • Toxic metabolite (norpropoxyphene) can accumulate and cause arrhythmias, pulmonary edema, apnea, and CV events. • Often used in suicides • Should be avoided in kids, older adults • Banned in Britain and many other countries but continues to be prescribed in U.S. • UPDATE: FDA just asked for withdrawal of propoxyphene from US market

  38. Review question • Proper administration of an ordered narcotic • A) can lead to addiction • B) should be done promptly to prevent increased pain and the need for larger doses • C) would include holding the drug as long as possible until the patient really needs it • D) should rely on the patient’s request for medication

  39. Other opioids • Meperidine (Demerol) - CII • Synthetic derivative of morphine • Despite some opinions, meperidine has not shown any benefit beyond other opioids for biliary colic, pancreatitis, labor, or migraine. • Does help with drug induced rigors, anesthesia related shivering • Toxic metabolite, normeperidine, limits it’s use • Accumulates with chronic use (>2 days), renal dysfunction • Very long T1/2, not reversible with naloxone • Causes seizures, hallucinations, agitation • Naloxone will reverse effects of meperidine, leaving normeperidine unopposed – risk of seizures! • Use > 2 days not appropriate

  40. Other opioids • Meperidine (Demerol) - CII • Drug interactions • serotonin syndrome • increased risk of MAO-I interactions and any serotonergic drug, including triptans • serotonin reuptake inhibition

  41. Other opioids • Nucynta (tapentadol) • CII • MOA • Opioid agonist (not as potent as morphine) • Norepinephrine reuptake inhibitor (NRI) • acts on decending pathway • Dosing • IR and ER forms available • 600mg max daily dose. Why? • Monitoring • CNS/RR depression • seizures, tachycardia, BP changes especially in patients taking antidepressants • Side effects • same as other opioids, but ~20% reduced incidence of GI S/E • NOT totally reversed by naloxone

  42. Other opioids • Tramadol (Ultram, Ultracet, Ryzolt) • Not related to opioids chemically • About as effective as Tyl#3 (codeine + APAP) • MOA: binds to Mu receptor, SNRI • Very little resp. depression, risk of dependence • Well tolerated, good for older folks

  43. Opioid antagonists • Block binding to opioid receptors, and can displace opioids bound there • Used for quick reversal of opioid toxicity/overdose • Reverses analgesia and CNS/resp. depression • Naloxone (Narcan), naltrexone (ReVia, Vivitrol) • Naloxone works within minutes of injection (SC, IM, IV) • Short DOA (1-2h), may need to be repeated

  44. Naloxone (Narcan) • For suspected narcotic OD • Give IVP over 10-15 sec • 0.4mg – 2mg • Repeat q 2-3 min if needed, up to total 10mg • If no effect at 10mg, probably not narcotic OD • No effect in the absence of opioids in system • Caution if suspected chronic opioid user, will precipitate immediate withdrawal

  45. Naloxone vs. Naltrexone • Naloxone • short acting competitive opioid antagonis • given parenterally, only 2% bioavailable PO • Used exclusively to reverse opioid intoxication • Naltrexone • given PO (Revia) and IM (Vivitrol) to treat alcohol dependence (main use) and opioid dependence (not very effective) • Vivitrol - monthly IM injection • Revia – PO QD

  46. Opioid withdrawal • Withdrawal • unlike withdrawal of benzodiazepines and barbiturates, opioid withdrawal is not life threatening • in otherwise neurologically and cardiovascularly healthy patients • Stage I – drug craving, anxiety (~5-15 hrs) • Stage II – yawning, perspiration, crying, rhinorrhea (~ 18 hrs) • Stage III – mydriasis, continuation of Stage II, hyperreflexia, hot/cold flashes, cramping (16-24 hrs) • Stage IV – continuation and worsening of Stage III, severe cramping, involuntary leg movements, diarrhea, HBP, ↑ body temp, ↑ RR, tachycardia, nausea (24 – 36hrs)

  47. Opioids withdrawal • Withdrawal • stage V – ↑ severity of earlier stages, fetal position, diarrhea, nausea, significant weight loss, leukocytosis, profuse sweating • stage VI – appetite returns, bowel function normalizes, beginning of psychological withdrawal symptoms, ↑ sensitivity to pain, GI symptoms • may see chronic withdrawal symptoms, both psychological and physical, after the post-acute withdrawal symptoms subside

  48. Opioids - NURSING CARE • Obtain baseline vital signs • Have naloxone available and know how to give it • Consider need for fixed schedule for patients experiencing chronic pain • Do not crush or break ER capsules/tablets

More Related