Term
| Opiate receptors are abundant at... (5) |
|
Definition
Dorsal horn of spinal cord
Periaqueductal greay
Rostral ventral medulla
Thalamic nuclei
Peripheral tissues |
|
|
Term
| Opiate receptor: properties (4) |
|
Definition
Structural and sterospecificity (L-isomer)
Subject to competition between and reversal of agonists and antagonists
Binding affinity correlated with efficacy
G-protein |
|
|
Term
| Mu-R binds _(3)_ and causes _(3)_ at Mu-1 and _(4)_ at Mu-2 |
|
Definition
Morphine
Synthetic opioids
Endorphins
Mu-1
Supraspinal analgesia
Euphoria
Miosis
Mu-2
Spinal analgesia
Respiratory depression
Physical dependence
Constipation |
|
|
Term
| Kappa-R binds ___ and causes ___ (3) |
|
Definition
Dynorphins
Spinal and supraspinal analgesia
Miosis
Sedation |
|
|
Term
| Delta-R binds ___ and causes ___ (2) |
|
Definition
Enkephalins
Spinal analgesia
Modulation of Mu-R |
|
|
Term
| Which receptors are responsible for supraspinal analgesia and miosis? (2) |
|
Definition
|
|
Term
| Endorphins: molecular origin, locations (3), cause for release |
|
Definition
Pro-opiomelanocortin
Pituitary, hypothalamus, 3rd and 4th ventricles
Painful episodes: released into CSF |
|
|
Term
| Dynorphins: molecular origin, properties, location |
|
Definition
Prodynorphin
Like enkephalins
CNS pain pathway nerve endings |
|
|
Term
| Enkphalins: molecular origin, locations, purpose |
|
Definition
Proenkephalin
CNS areas that perceive pain
Regulate NT release = inhibit transmission of painful stimuli |
|
|
Term
| Opiopeptins: properties (4) |
|
Definition
High affinity for opiateR
Exhibits cross-tolerance with narcotic agonists
Chronic use produces dependence
Binding reversed by narcotic antagonists, which can cause withdrawal |
|
|
Term
| Oral absorption is usually ___ and variable due to ___. |
|
Definition
Poor
First-pass metab and glucuronidation |
|
|
Term
| ___ administration is usually complete, and ___ and ___ administrations are usually effective |
|
Definition
IM
Transdermal and epidural |
|
|
Term
| Distribution to tissues is based on ___. CNS levels depend on _(4)_ |
|
Definition
Blood flow
BBB
Lipid solubility
Protein binding
Hepatic conjugation with glucuronic acid |
|
|
Term
|
Definition
Water soluble metabolites excreted in urine
Glucuronide conjugates excreted in bile |
|
|
Term
|
Definition
1. Presynaptic agonist = decreased Ca influx = decreased excitatory NT release
2. Postsynaptic agonist = increased K conductance = hyperpol and decreased responsiveness |
|
|
Term
|
Definition
Analgesia
-Interact with Mu and Kappa receptors: inhibit nociception at spinal and supraspinal sites = increased threshold for pain perception and diminished reaction to pain (even though still perceived)
-Better for continuous dull pain that intermittent sharp pain
Sedation (due to decreased anxiety?)
Euphoria or detached/floating sensation |
|
|
Term
| Opiates: respiratory effects |
|
Definition
Decrease sensitivity of respiratory chemoR to CO2
Directly decrease respiratory rhythm
Both cause dose-dependent decreased rate, minute volume, tidal exchange |
|
|
Term
| Opiates: other central effects (4) |
|
Definition
Cough suppression (direct depression of medullary cough center)
Miosis (increased parasymp activity)
Truncal rigidity (increased descending motor impulses)
n/v (direct stim of chemoR in medullary area postrema) |
|
|
Term
| Opiates: peripheral effects (3) |
|
Definition
Mostly Mu-mediated
Histamine release: flushing, itching, hypotension
Orthostatic hypotension (morphine)
Increased smooth muscle tone
-Intestines: along with decreased propulsion
-Biliary tract: increased biliary pressure
-Urinary tract: retention |
|
|
Term
| Solely Mu agonist drugs (2) |
|
Definition
|
|
Term
| Agonist for all 3 opiateR |
|
Definition
|
|
Term
| Antagonist for all 3 opiateR |
|
Definition
|
|
Term
| Mu partial agonist and Kappa agonist (3) |
|
Definition
Butorphanol
Nalbuphine
Buprenorphine = only Mu |
|
|
Term
| With repeated admin, tolerance can develop over ___ |
|
Definition
|
|
Term
| Tolerance is gained to all effects except... (3) |
|
Definition
Miosis
Constipation
Convulsions |
|
|
Term
| Cross tolerance to all opiates occurs and includes tolerance to _(4)_ effects |
|
Definition
Analgesia
Euphoria
Sedation
Respiratory depression |
|
|
Term
| Less tolerance is gained to ___ |
|
Definition
| Partial agonist/antagonists |
|
|
Term
|
Definition
| Decreased receptor-ion channel coupling |
|
|
Term
|
Definition
| Without the depressive effects of the agonist binding to the receptor, the affected processes become hyperexcitable = withdrawal |
|
|
Term
| Think twice about giving opiates to these patients (4) |
|
Definition
Pulmonary disease
Hepatic dysfunction
Head injury without assisted ventilation
Pancreatitis |
|
|
Term
| Opiate toxicity: S/E (3), tx (2) |
|
Definition
Triad
-Depressed respiration
-Pinpoint pupils
-Coma
Airway, see to the CNS depression or excitation
Narcotic antagonist |
|
|
Term
| Naltrexone is a pure ___, is ___ than naloxone, and can be ___ |
|
Definition
Antagonist at opiateR
Longer-acting
Orally administered |
|
|
Term
| Buprenorphine: indication |
|
Definition
| Decrease opiate craving (Mu-R partial agonist with long t1/2) |
|
|
Term
| Full antagonists can be used to reverse the respiratory/CNS effects as well as ___, but the problem is that ___ |
|
Definition
Orally to decrease craving and maintain sobriety
It can reverse all the beneficial effects of the agonist including the analgesia |
|
|
