OPIOIDS Flashcards
(48 cards)
Tolerance is used to describe when
patients require increasing dosages of opioids to have the same clinical effect.
Dependence can be either
It is the presence of withdrawal symptoms when the drug is withheld. May be physical or psychological.
Types of Opioids
agonists, antagonists, or mixed agonists/antagonists.
What are the different types of Opioids receptors?
Mu1, Mu2, Kappa , Delta
Principal mechanism of action of all opioids
Through Mu receptor agonism
Principal mechanism of action of all opioids
Through Mu receptor agonism
Opiates mimics endogenous peptides such as endorphins
Effects of opioids is based on
Depends on which G-COUPLED receptors to which receptor they bind to
Metabolism of most opioids? What do you have to consider?
Most undergo biotransformation in the liver. Consider reducing the dose for patients with liver and kidney failure
Metabolites opioids and kidney failure
May accumulate with kidney failure patients.
Endogenous opioids
Peptide endorphins are the naturally occurring ligands for opioid receptors.
Where are the opioids receptors located? the the
– sensory neuron of the peripheral nervous system;
– dorsal horn (layers 4 and 5 of the substantia gelatinosa) of the spinal cord, which inhibits the transmission of nociceptive information;
– brainstem medulla, which potentiates descending inhibitory pathways that modulate ascending pain signals; and the
–cortex of the brain, which decreases the perception and emotional response to pain
Opioid receptor activation inhibits the
presynaptic release and postsynaptic response to excitatory neurotransmitters
Excitatory neurotransmitters are
Glutamate
Acetylcholine
Substance P
2 highly lipids soluble opioids and their implications
The highly lipid-soluble opiates, such as fentanyl and Sufentanil, have a rapid onset and short duration of action
Metabolites of mophine and meperidine and their implications?
morphine and meperidine, have metabolites—morphine-6-glucoronide and normeperidine, respectively—that are equally active as the parent compound.
Opiods of CBF, CMRO2, ICP
Opioids can reduce cerebral metabolic O2 requirements, cerebral blood flow, and intracranial pressure if alveolar ventilation is unchanged in a healthy patient;
Opiods with patients with TBI
May increase ICP with patients with TBI even with controlled ventilation.
Opioids and GI
an cause contraction of the sphincter of Oddi. This contraction can mimic biliary colic, but it is responsive to antagonism of the opioids or the use of glucagon.
Opioids and Respiratory
decreases minute ventilation by decreasing the respiratory rate (as opposed to decreasing the tidal volume)
Opioids and Respiratory : CO2
Producing a dose-dependent depression of the ventilatory response to CO2.
Opioids and the The apnea threshold
The apnea threshold, defined as the highest PaCO2 without ventilatory effort, is increased with the use of opioids.
2 Can cause histamine-induced bronchospasm
morphine and meperidine
Opioids and MUSCULOSkeletAL
Opioids can produce generalized skeletal muscle rigidity, a phenomenon associated with the more potent opiates (e.g., fentanyl, sufentanil, carfentanil).
Musculoskeletal changes that can occur with the administration of opioids?
Loss of chest wall compliance and contraction of the laryngeal and pharyngeal muscles can be severe, resulting in ventilatory difficulty, even with positive-pressure ventilation.
