OPIOIDs Flashcards
Activation of u receptors cause what behavioral changes?
Analgesia
euphoria
respiratory depression
Physiological dependence
delta and kappa receptors contribute to what effect?
and at what level do they act?
Contribute to analgesia particularly at the spinal level.
mu kappa and delta receptors (all are G protein) assert functional effects on:
supraspinal analgesia
spinal analgesia
mu asserts functional effects on:
Respiratory depression Supraspinal analgesia spinal analgesia reduced GI motility Sedation
mu and delta assert functional effects on:
reduced motility
Kappa
psychotomimesis (symptoms of psychosis)*
sedation
spinal analgesia
supraspinal analgesia
mu and Kappa receptors assert functional effects on:
sedation
- At high concentrations what drug is known to cause seizures?
- What may cause the increase in concentration?
- Normeperidine a metabolite of meperidine.
2. Decreased renal function causes the accumulation of the metabolite
What are opioids converted to before they get excreted by the kidneys?
Example?
Glucuronides
example Morphine is conjugated to Morphine-3-glucuronides (M3G)- a compound with neurotoxicity.
How are esters like heroine and remifentanil hydrolyzed?
They are hydrolyzed by tissue esterases
example: Heroin is hydrolyzed to monoacetylmorphine–> morphine–>conjugated to glucuronic acid.
What happens to patients w/ decreased renal function?
accumulation of meperidine and normoperidine may occur. Causes seizures at high doses!!!
Where and what metabolizes Fentanyl?
and what are it metabolites?
CYP 3A4 in the liver.
Fentanyl has no active metabolites
100 times more potent than morphine!!.
Rapid onset short duration.!!!
Where and what metabolizes Codeine/Oxycodone and hydrocodone?
and what are it metabolites?
CYP 2D6 in the liver.
Metabolites with greater potency are formed eg. morphine from codeine.
opioid derivatives most commonly used as antitussives are:
Dextrometorphan and codeine
Most commonly used drugs to control diarrhea?
What receptors mediate actions of these drugs?
Do they have analgesic effects at their usual doses?
Loperamide (imodium) and diphenoxylate (AKA Lomotil-formulated with Atropine to reduce abuse potential) mu and delta
they lack analgesic effects!