Drugs for Pain - Opiods/Adjuvant Analgesics

opioid analgesic

morphine, relieves severe pain with remarkable efficacy

incision of poppy seed reveals a white substance that turns into a brown gum which harvests:

morphine, alkaloids of crude opium

what are the three receptors in the CNS tissue?

Mu, Kappa, Delta

which receptor the most clinically useful as opioid analgesics have strong selectivity for them?

Mu receptors

the opioid receptors do what in terms of pain management:

alters perception of pain

what are our bodys own "endogenous opioids"

endorphins enkephalins, dynorphins

what are the three types of opioid analgesics?

pure opioid agonists or full agonists

which opioids are used for severe pain?

strong opioid agonists

which opioids are used for moderate to mild pain? (sometimes given with a non-opioid analgesic)

moderate opioid agonists

which kind of pain requires higher doses of opioids?

neuropathic pain

which kind of pain can respond to opioids but not NSAIDs?

neuropathic pain

opioids play a major role in the treatment of:

acute pain, breakthrough pain, cancer pain, some types of non-cancer pain

analgesia, sedation, euphoria/dysphoria, miosis, nausea/vomiting, anti-tussive, resp. depression

CNS effects of pure opioid agonists

what is the main cause of death in opioid overdoses?

respiratory depression

describe the process of respiratory depression in opioid overdoses:

decreased ventilation --> increased CO2 levels --> increased intracranial pressure --> respiratory acidosis and comas

opioids are typically contradicted in which patient population?

asthma/COPD patients

cardiovascular effects of Opioids:

vasodilation, decreased myocardial oxygen demand

GI/Biliary effects of opioids:

constipation, gallstones

genitourinary effects of opioids:

increased tone of urethral sphincters --> urinary retention

increased release of ADH

suppression of uterine tone/motility

immune/dermal effects of opioids:

suppresses lymphocyte activity, itching/pruritis, flushing

sedative-hypnotics and alcohol can produce which kind of reaction when given with opioids:

CNS depression, respiratory depression

side effects of antipsychotics with opioids:

increases sedation

which drug in combination with opioids may enhance opioid-induced constipation or urinary retention?

antimuscarinics

many drugs also inhibit the CYP450 enzymes which metabolize ___________, what would this do to the patient?

opioids, would result in an overdose (increase plasma concentration of the drug)

tactics to overcome constipation while taking opioids:

- OTC osmotic laxatives (polyethylene glycol)

- stool softeners (usually ineffective)

- incorporate fluids/fiber/activity

what can happen when a patient is on a long-term use of opioids?

they could become tolerant due to down regulation of opioid receptors

decrease in pharmacologic effect observed after chronic or long-term administration

tolerance

a physiologic state in which a person's continued use of the drug is required for his or her well being:

physical dependence

what can occur when someone who is tolerant to one opioid is switched to another opioid and likely has some tolerance to the new opioid:

cross-tolerance

opioid withdrawal syndrome:

irritability, autonomic hyperactivity

withdrawal from a short acting opioid:

more intense, but briefer

how to precipitate withdrawal symptoms in a physically dependent individual:

discontinuing drug, reducing dose, or administering a pure narcotic antagonist/mixed antagonist

what helps clinicians determine the appropriate starting dose of an opioid when changing routes of administration or changing patients from one opioid to another?

equianalgesic dosing charts

morphine, hydromorphone, fentanyl, meperidine, oxycodone and methadone are all:

strong opioid agonists

which routes of administration are preferred for strong opioid agonists:

oral or transdermal administration

what is a popular administration of opioids with in-patient settings?

PCA pumps

in contrast to non-opioids, strong opioids no not have a:

ceiling effect

what is the first choice of opioid to relieve moderate to severe pain?

morphine

why are large doses of morphine required when the drug is administered orally compared to paraentally?

extensive hepatic first-pass effect

morphine is well absorbed from:

injection sites

pain relief from morphine administered subC starts:

10-20 mins and lasts 4-6 hrs

main metabolites of morphine, where are they typically excreted?

inactive glucuronides, primarily urine small fraction eliminated in the bile

main uses of morphine:

trauma pain, cancer, post-op and MI

why is morphine used for MI patients?

vasodilating properties

injectable forms of morphine:

astromorph, infumorph, duramorph

oral forms of morphine:

kadian, avinza, MS contin

epidural forms of morphine:

DepoDur

some healthcare providers have mistakenly thought of which drug as the equivalent to morphine, when in reality it is actually:

hydromorphone, 5-6x more potent than morphine

administering hydromorphone instead of morphine has resulted in;

respiratory arrest and death

how is hydromorphone available:

tablets, liquid and injectables