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how does an opioid differ from an opiate

opioid is a generic term referring to all drugs with morphine-like actions

opiate is morphine, codeine, other semisynthetic derivatives of morphine from opium

what are the 3 main opioid receptor types

mu, delta, kappa

what are the pharmacological effects of mu receptors

side effects---euphoria, resp depression, inhibiton of GI motility

mu receptors cause most clinically relevant analgesia------mu 1 mediates supraspinal analgesia & mu 2 mediates spinal analgesia

what are the pharmacological effects of kappa receptors

mediates both spinal and supraspinal antinociception

poss sedation and dysphoria

what are the pharmacological effects of delta receptors

mediates mainly at spinal, but also supraspinal antinociception

poor analgesia

what is a full opioid agonist and what drugs does this include

affinity and activity at all clinically relevant opioid receptors

morphine, codiene, meperidine, oxymorphone, hydromorphone, fentanyl, methadone, carfentanil

what is a partial opioid agonist and what drugs does this include

affinity but only partial activity for some opioid receptors

buprenorphine, nalorphine, tramadol, levallorphan

what is a mixed agonist-antagonist and what drugs does this include

affinity for multiple opioid receptors but are agonist at some receptors and are antagonist or weak agonist at other receptors

butorphanol & pentazocine

what is an opioid antagonist and what drugs does this include

affinity for all opioid receptors but no activity

nalaxone, diprenorphine, naltrexone

what are the CNS pharmacological effects of opioids incl effect on temp, vomiting center, cough center (in particular morph)

CNS depression--dogs, monkeys, humans
CNS stimulation--cats, horses, ruminants, pigs
hypothermia--dogs, rabbits, monkeys; hyperthermia--cats, swine, ruminants, horses
small dose, puke; large dose, no puke; no puke--swine, chickens, horses, rabbits, rum
inhibits cough center, but addictive, so no

what are the pharmacological effects of opioids on the eye (morph)

miosis in sp that become sedate (dogs, humans...b/c occulomotor n stimulation)
pupil dilation in sp that become excited (cats, sheep, horses, monkeys)

what are the pharmacological effects of opioids on the resp syst (morph)

initial stimulation of resp in dogs at sm doses (dissipate heat); decreases after time (and large dose).....mu2 activation depresses brain resp centers

what are the pharmacological effects of opioids on the cardio syst (morph)

coronary vasoconstriciton in dogs (poss d.t. activation of alpha receptors); brady and vasodilation d.t. vagal stim.; cerebral vasodilation---increases ICP

what are the pharmacological effects of opioids on the GIT, urin syst, imm syst (morph)

GI: vomiting, followed by constipation (segmental m contraction & relaxation of longitudinal m)
URIN: mu ag decrease urine d.t. ADH stim; kappa ag inhibit ADH, so increased urine; detrusor inhibition
IMM: histamine release if IV; natural endorphans; inhibition of apoptosis during ischemia

what drugs have a ceiling effect and why is this important

butorphanol & buprenorphine.............cardio safter, but give less pain relief d.t. their ceiling effect

how do opioids cause vomiting

via the CRTZ

how do opioids inhibit cough

inhibit the cough center

how do opioids cause miosis

oculomotor nerve firing (increased parasympathetic)

how do opioids cause mydriasis

catecholamine release prevents miosis

why do opioids initially stimulate resp and then sometimes decrease resp after the initial stimulation

at 1st panting b/c trying to dissipate heat; mu2 activation depresses brain

how do opioids cause potential cardio depression


what causes constipation with opioids


how do opioids inhibit urination


where are opioids metabolized and excreted


what about the pharmacokinetics limits oral availability of opioids


what are uses of opioids


what are the adverse effects and contraindications of opioids


which opioids have short lived analgesia


which opioid has the longest lasting analgesia


which opioids are weaker analgesics


why is buprenorphine difficult to reverse


why are full agonists less effective after using butorphanol or buprenorphine


which opioids are used as emetics


which opioids are used as antitussives


which opioids are used as antidiarrheals


which opioids cause histamine release and what route of administration is more likely to cause histamine release


how are most opioids given


which opioids are most commonly given orally (to send home as analgesics or cough suppr)


which opioid agonists (full, partial, mixed) are more potent (greater receptor binding affinity) than morphine


which opioid has a spasmolytic effect on sm m


which opioid has a vagolytic effect rather than an increased vagal effect


what opioid is very lipid soluble and therefore is quick-acting and short-lasting


which drug is fentanyl combined with and sold as innovar vet (neuroleptoanalgesic)


what are the pharmacological effects of innovar vet


what are the therapeutic uses effects of innovar vet


what are the adverse effects of innovar vet


what breed is resistant to innovar vet but more sensitive to side effects


how can salivation and bradycardia be controlled when using innovar vet


what is a reported reversal agent for innovar vet


how long does it take the fentanyl patch to work in cats, dogs, horses


how long does the fentanyl patch work


what are some precautions with the fentanyl patch


which opioid may also inhibit serotonin and NE uptake


for which type of analgesia is butorphanol best


for which opioid should naloxone not be used


if an opioid is more potent, does that mean it provides better analgesia


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