Opioids Flashcards
What exogenous opiods (aka narcotics) are used for
Can be used for instrumental and recreational use.
Instrumental: Pain medication (chronic and acute pain)
Recreational: Street drugs
Note: High abuse potential. Can be lethal (especially fentanyl), as it can shut down the ability to breathe.
Formerly called opiates if they were derived from the opium poppy, now typically all called opioids.
Why are opioids legal if they have such high potential for abuse?
The instrumental value of opioids is too high for them to be prohibited
Naturally occuring opiods
Opium from the opium poppy has these active ingredients:
Morphine, codeine, thebaine, narcotine
Narcotine is unpleasant, it causes vomiting.
What are the five semi-synthetic opioids discussed in class?
- Diamorphine/diacetylmorphine (heroin) – from morphine
- Desomorphine (krokodil) – from codeine (people tried to make it by cooking codiene and harmed themselves)
- Buprenorphine (partial opiod receptor agonist, analgesic, weaker than morphine and has lower risk of causing breathing problems)
- Hydrocodone
- Oxycodone (aka oxycontin)
Your muscles can atrophy from the toxic byproducts in krokodil.
Buprenorphine
Partial opiod receptor agonist, analgesic, weaker than morphine and has lower risk of causing breathing problems
Desomorphine (krokodil)
Made from codeine (people tried to make it by cooking codiene and harmed themselves). Your muscles can atrophy from the toxic byproducts in krokodil.
Three fully synthetic opioids
Fentanyl
Carfentanil
Methadone
Typically, synthetic drugs are most potent.
Dextromethorphan was considered a synthetic opioid but is not classified as one anymore.
Methadone
Used in drug replacement therapy
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Drug history placeholder
Out of class during this time, fill in later
The three main forms of opioid administration
Oral - eg. methadone substitution
Inhalation - a.k.a. “chasing the dragon” (inhaling heated drug smoke through a straw)
Intravenous (IV) injection - a.k.a. “mainlining”
With opioids, potency is determined by [answer], not pharmacodynamics
Lipid solubility - how bioavailable is the drug, how well can it pass through the
(acetyl groups improve the BBB permeability)
Opioids are metabolized in the [answer]
Liver
Heroin drug tests look for [answer].
Monoacetylmorphine (heroin specific metabolite)
Endogenous neurotransmitters are large [blank] cleaved from very large [blank]
peptides, propeptides
The four endogenous opioid propeptides
- Proopiomelanocortin (POMC)
- Proenkephalin
- Prodynorphin
- Pronociceptin (weird one)
β-endorphins activate which receptors?
μ (mu) and δ (delta) receptors
Dynorphin A & B and neoendorphins activate which receptors? What effect do the type of receptors activated have?
κ (kappa) receptors, which can cause occasional hallucinogenic effects.
Robotripping
Using robitussin DM, which affects MDMA receptors, people get high. Robotussin DM is not an opioid, but is an agonist for opioid receptors and antagonist for NMDA receptors.
Nociceptin activates which receptors? What effects does it have?
It activates ORL-1 receptors, which can cause pain.
Activation of endogenous opioid receptors open [answer].
GIRKs
What are GIRKs?
G-protein-coupled inward rectifying K+ channel
In other words, these are potassium ion channels.
GIRKs
Opioid agonists: Examples and which receptors they effect
Heroin, morphine, fentanyl, etc.
Most effects are via delta and mu receptors
Opioid antagonists: Examples and uses
Naloxone (narcan): For reversing opioid
Effects of opioids
- Analgesia
- Constipation
- Decreased blood pressure
- Euphoria
- Hypothermia
- Relaxation
- Respiratory depression
Nociception
The perception of pain
Analgesia
Pain relief
The brain produces endogenous opioids for [answer].
Pain relief
Two notable regions for endogenous opioid neurons and what they do
Periacqueductal gray (PAG): Has opioid producing neurons that direct to the raphe nuclei and modulate pain.
Spinal cord interneurons: Release opiates/serotonin to prevent pain signals from reaching the brain.
Opioids and stages of euphoria
Initial rush, then high, then nod (calm, sometimes unaware of surroundings, may fall asleep), then straight (period of normalcy between cravings and euphoria).
Tolerance builds for euphoric effects, thus people have to take higher doses to get the same effects.
Opioid reward mechanisms
Opioid uses DA release from VTA to NAcc.
Seemes to increases DA release in VTA by inhibiting the inhibitory GABA neurons.
Conditioned place preference (CPP)
Different solutions administered (vehicle vs opioid) in different chambers. A rat will prefer to stay in the chamber that an addictive drug has been administered in. A rat will avoid a chamber if an aversive drug has been administered in said chamber.
Tolerance develops for which effects of opioids? How fast does tolerance build?
All effects. Tolerance builds to opioids very quickly.
Long term use of opioids can lead to reduced activity at the [answer].
Sodium-potassium pump
Opioid overdose symptoms
- Severe respiratory depression
- Weakness
- Inability to speak
- Bluish lips and skin
- Unconsciousness
Name several
Symptoms of opioid withdrawal
Incredibly adverse effects:
- Pain
- Irritability
- Panting/yawning
- Dysphoria, depression
- Restlessness/insomnia
- Diarrhea
- Pupil dialation
- Hyperthermia
- Tearing, runny nose
- Spontaneous ejaculation
- Chilliness and “gooseflesh”
What percent of heroin users started on prescription opioids?
75%
