Opiate Analgesic Drugs Flashcards
Strong Opiate Agonists
Morphine
Fentanyl
Methadone
Meperidine
Oxycodone
Sufentanil
Heroin-Purdrug
Moderate Opiate Agnoists
Codeine
Hydrocodone
Propoxyphene
Opioid Antagonists
Naloxone
Naltrexone
Prototype U agnoist
Morphine
Strong lipophilic u agnoists
Fentanyl
Long duration, also used for opiate addiction
Methadone
Active metabolite can be toxic
Meperidine
Used for breakthrough pain (postsurgical pain)
Oxycodone
Strong lipophilic u agnoist
Sufentanil
(Diacetylmorphine; not approved for medical use in the US)
P-450 inhibitors can induce withdrawal in opiate addicts
Heroin-Prodrug
(Prodrug methylmorphine)
USed to treat mild-moderate pain
Codeine
Combined with acetaminophen or NSAIDs
Hydrocodone
Deadly if mixed with ETOH
Propoxyphene
Parenternal
Naloxone
Oral
Naltrexone
Opioid analgesics are used how?
Relieve moderate to severe pain
What happens when endogenous opioid peptides are released from nerve endings?
They interact with opioid receptors in the CNS, and the primary afferent neurons to modulate pain transmission
Major opioid receptor subtypes?
Mu
Delta
Kappa
All three receptors are couple to what?
G proteins (GPCR)
When opioid receptor subtypes are coupled with G proteins what happens?
Activates phospholipase C (PLC) or inhibits adenylyl cyclase (AC)
Medical term for ‘pain’
Nociception
Pain can be defined as..
Physical suffering caused by illness or injury
It can impact QOL and the ability to carry out daily tasks
Why is management of pain a challenege?
Pain is subjective
Clinicians rely on what?
Patients perception and description of pain
Acute pain
Temporarily in nature
Usually goes away when the cause of pain has been removed
Chronic pain
As neuropathic pain resulting from nerve damage lasts for months
Parimily produce pain relief
Opiates which are mu recepros agaonists in the CNS
What are opiates that are mu receptors agonists primarily used for?
Treat moderate to severe acute and chronic pain
Pain stimuli are carried to the CNS
Nociceptive fibers
Once the nociceptive impulse arrives in the dorsal horn of the SC, what occurs?
Secondary afferent neuron carries the information across the ventral white commissure to the contralateral side where the axon ascends to the brain, resulting in the feeling of pain
Opioids exert what effect?
Analgesic
Once opioids exert analgesic effects…
Decreasing the ascending (afferent) pain transmission and activating the descending (efferent) pathways that reduce pain.
Descending Pain-Inhibitory System
Comprised of descending serotonergic and noradrenergic nerve fibers that synapse upon and inhibit nociceptive input to the SC
The analgesic efficacy of opiates can be facilitated by the simultaneous use of _________ to enhance the synaptic activity of 5-HT and/or NE in the dorsal horn of the SC
adjunctive analgesics (ex: tricyclic antidepressants
How do antidepressants such as amitriptyline produce analgesics (for treating neuropathic pain)?
Inhibiting spinal NE and 5-HT uptake, these drugs enhance the action of the descending pain-inhibitory pathway
By increasing NE and 5-HT in the spinal dorsal horn, these drugs decrease the release of nocicepetive neurotransmitters like substance P and glutamate
