Pharmacology- Pain and Inflammation Management Drugs- FINAL EXAM

what is pain physiology?

-pain begins with activation of nociceptors in response to tissue injury

-signals travel through peripheral nerves →spinal cord → brain

what is nociceptive pain?

- pain that arises from damage to or inflammation of tissue other than that of the PNS and CNS

- usually throbbing, aching, localized

-caused by TISSUE INJURY can be somatic (skin or muscle) or visceral (internal organs)

what is neuropathic pain?

-pain that arises from abnormal or damaged pain nerves --ex: phantom limb pain, pain below the level of a spinal cord injury, diabetic neuropathy

-usually intense, shooting, burning, or "pins and needles"

-caused by NERVE INJURY and responds poorly to opioids

what is ischemic pain?

-results from a profound, sudden loss of blood flow to an organ or tissue

-priority is to treat the cause of decreased tissue perfusion

-example: acute myocardial ischemia

-nitroglycerin improves perfusion

-morphine relieves pain and anxiety

-goal is to restore oxygen supply to tissues

what are non-opioid analgesics?

-NSAIDs and acetaminophen

-mild to moderate pain, fever, inflammation (NSAIDs)

what is acetaminophen?

-not an NSAID and not good for inflammation

-used to treat minor aches and pains and reduce fever

-preferred to NSAIDs for children suspected of having a viral infection like chicken pox or influenza

-overdose may cause fatal liver damage

what is the MOA of acetaminophen?

-slows production of prostaglandins in the CNS

-acts on the hypothalamus to reduce fever

-not an anti-inflammatory drug

what are the therapeutic dosages of acetaminophen for varying patient populations?

-4 g/day for most patients

-3 g/day for undernourished patients

-2 g/day for patients who consume more than three servings of alcohol daily

what are acute toxicity signs and symptoms for acetaminophen?

-liver damage with early manifestations like N/V, diarrhea, sweating, abdominal discomfort progressing to hepatic failure, coma, death

-indications of hepatic injury appear 48 to 72 hours after ingestion

-administer antidote which is acetylcysteine

what are the nursing administration factors for acetaminophen?

-teach patients to read medication labels carefully

-administer orally with full glass of water, with or without food

-if pain or fever persists for more than 3 days, contact provider

what are non-steroidal anti-inflammatory drugs (NSAID's)

-first-generation (COX-1 and COX-2 inhibitors) =aspirin, ibuprofen, naproxen, indomethacin, ketorolac

-second-generation (selective COX-2 Inhibitor) =celecoxib

what are the uses for NSAID's?

-inflammation suppression

-fever reduction

-dysmenorrhea

-inhibition of platelet aggregation (aspirin)

what are the main differences between COX-1 and COX-2 NSAID's?

-COX-1 = can result in decreased platelet aggregation and kidney damage

-COX-2 = results in decreased inflammation, fever, and pain and does not decrease platelet aggregation

what are the complications associated with NSAID's?

-GI discomfort

-impaired kidney function

-increased risk of heart attack and stroke

-salicylism with aspirin

-reye syndrome (rare but serious complication)

-aspirin toxicity

what are signs of salicylism?

-tinnitus, sweating, headache, dizziness and respiratory alkalosis

what is reye syndrome?

-a rare but life-threatening condition that causes acute brain swelling (encephalopathy) and liver dysfunction in children

-strongly associated with giving kids aspirin

what are the contraindications of first generation NSAID's?

-pregnancy

-peptic ulcer disease

-bleeding disorders

-hypersensitivity to aspirin and NSAIDs

-aspirin contraindicated in children and adolescents who have a viral illness

-ketorolac contraindicated in patients who have advanced kidney disease can use NO LONGER than 5 days

what are the contraindications of second generation NSAID's?

-celecoxib is last-choice for chronic pain b/c of increased risk of MI and stroke due to suppression of vasodilation

what are the nursing administration factors for ketorolac?

-short-term treatment of moderate to severe pain (post-op pain)

-use with opioids allows for lower dosages of opioids

-usually first administered parenterally and then switched to oral

what are the nursing administration factors for ibuprofen?

-IV infused over 30 minutes

-hydrate patient to prevent kidney damage

what are patient education factors for NSAID's?

-stop aspirin 1 week before elective surgery or expected date of child birth

-take NSAIDs with food, milk, or 8 oz of water

what are opioid agonists?

-bind to opioid pain receptors in the brain and causes an analgesic response (reduction of pain sensation)

-act on mu receptors and, to a less degree, kappa receptors

-morphine, fentanyl, meperidine, methadone, codeine, oxycodone

-used for moderate to severe pain, reduction of bowel motility relief of diarrhea and cough suppression

what symptoms do activation of mu receptors cause?

-produces analgesia, respiratory depression, euphoria, sedation

what symptoms do activation of kappa receptors cause?

-analgesia, sedation, decreased GI motility

what are the complications associated with opioid agonists?

-respiratory depression

-constipation

-orthostatic hypotension

-urinary retention

-cough suppression

-sedation

-N/V

opioid toxicity triad which includes coma, respiratory depression, and pinpoint pupils

what are the nursing administration factors for opioid agonists?

-assess pain level on a regular basis and take baseline vitals

-double-check opioid doses with another nurse

-administer IV slowly over 4-5 minutes and have naloxone and resuscitation equipment available

-do not discontinue abruptly

-closely monitor patient-controlled analgesia (PCA) pump settings (dose, lockout interval, 4-hour limit)

-first administration of transdermal fentanyl patch will take several hours to achieve desired therapeutic effect

what are opioid antagonists?

-naloxone

-drugs that block the effects of opioid agonists by blocking opioid receptors REVERSING the effects of opioids

-have no effect in the absence of opioids

what is naloxone used for?

-reversal of effects of opioids specifically respiratory depression

-reversal of respiratory depression in an infant

what are the complications associated with naloxone?

-tachycardia and tachypnea

-abstinence syndrome which includes cramping, hypertension, vomiting, and reversal of analgesia

-contraindicated in patients who have opioid dependency

what are the nursing administration factors for opioid antagonists?

-do not administer naloxone orally

-observe withdrawal manifestations or abrupt onset of pain

-titrate naloxone dosage to achieve reversal of respiratory depression without full reversal of pain management effects

-rapid infusion can cause hypertension, tachycardia, N/V

-monitor respirations for up to 2 hours after use to assess for recurrence of respiratory depression and need for repeat dosage of naloxone

what are adjuvant drugs for pain?

-used with a primary pain medication

-usually an opioid agonist, to increase pain relief while reducing dosage of opioid agonist

-developed to treat other conditions

what are the categories included as adjuvant drugs for pain?

-tricyclic antidepressants (amitriptyline- oral)

-anticonvulsants (carbamazepine- oral, gabapentin- oral)

-cns stimulants (methylphenidate- oral, transdermal)

-antihistamines (hydroxyzine- oral, im)

-glucocorticoids (dexamethasone- oral, iv, im)

-bisphosphonates (etidronate- oral)

nsaids (ibuprofen- oral, iv)

what are anti-gout drugs?

-allopurinol

-colchicine

what is colchicine?

-anti-inflammatory gout drug for exacerbations and flare-ups

-inhibits migration of leukocytes to the inflamed site

-effective at alleviating acute symptoms of gout

-does not inhibit uric acid synthesis or promote uric acid excretion

-should be taken with food to decrease gastric irritation

what is allopurinol?

-not an anti-inflammatory drug used for prophylaxis

-increases uric acid excretion in urine

-reduces uric acid production, preventing the precipitation of an attack

-prevent gout and commonly used for chronic tophaceous gout