Narcotics and Abuse Flashcards
Opioid mechanism of action
receptors in brain, spinal cord, and peripheral nerves, inhibit the release of substance P and its transmission from the dorsal horn
Opioid receptors and how opioids block signaling
GCPRs, the increase K+ efflux and inhibit Ca influx-> inhibits cAMP production
Op receptor subtypes, which is most targeted
Mu, delta, kappa: Mu is most targeted
Actions of Mu receptors
analgesia, decreased respiration, decrease GI motility, Increased appetite, sedation, decrease release of ACh and DA, miosis
Op tolerance
desensitization, receptor internalization
Bolus effect
effects could wear off before next dose because of its short half life, could make the patient appear to be drug seeking
Morphine
two major active metabolites, M6 is most active
Codeine
low receptor affinity, converted to morphine; because it is metabolized by CYP2D6, some caucasians may not be able to convert
Tramadol
synthetic codeine analog, less effective for severe pain but less constipation and less addicting
Fentanyl
very potent, long half life, patch for long term effect, be careful when changing dose
methadone
treat chronic pain and heroine users, very long half life and inexpensive
Oxycodone
very effective, oral agent, long acting, wide spread abuse and overdose
Meperidine
no longer recommended
Opioid antagonists
naloxone and nalmefene (opioid toxicity), naltrexone (alcoholism)
Caution with acetaminophen
most opioids are given in combination with acetaminophen, counsel patients
Fomepizole
blocks alcohol dehydrogenase; methanol or ethylene glycol poisoning
CNS Stimulants
Cocaine, amphetamines
Cocaine
- Neurotransmitter
- Mechanism and effect
- toxicity
- withdrawal
CNS stim
- NE, DA, and 5HT
- block NT reuptake and local anesthetic: increased HR, RR, BP, contractility, mydriasis
- arrhythmias, ischemia, psychosis, delirium, convulsion, hyperpyrexia, death
- craving, severe depression, anhedonia, anxiety
Amphetamine
- NT
- Mech and effect
- toxicity
- withdrawal
CNS stim
- NE and DA
- block reuptake, release NTs from mobile pools and inhibit MAOs: psychosis, paranoia, hallucinations, sympathomimetics
- same as coke
- same as coke
Benzos
- NT
- Mechanism and effect
- toxicity
- reversal
- withdrawal
CNS depressant
- GABA
- helps GABA bind better, faster, and longer: mild to moderate CNS depression
- sedation, anterograde amnesia
- flumazenil
- rebound insomnia and anxiety
Barbituates and Ethanol
- NT
- Mechanism and effect
- toxicity
- withdrawal
CNS depressant
-GABA
-prolong GABA action and mimic GABA at high concentrations: Severe CNS depression
-No limit to CNS depression, fatal
- agitation, anxiety, seizures
for alcohol there is delusion, hallucinations, delirium tremens
Opioids
- NT
- examples
- Mechanism and effect
- toxicity
- reversal
- withdrawal
analgesics, sedative
- All of them.
- morphine, heroin, methadone, fentanyl, hydrocodone
- activate Mu receptors: euphoria, analgesia, sedation, constipation, miosis
- severe respiratory depression, nausea, vom
- naloxone
- SLUDGE, pain, muscle cramping, diarrhea
Hallucinogens
- examples
- NT
- mechanism and effect
- toxicity
- withdrawal
- LSD, mescaline, psilocybin
- 5HT
- 5HT2A agonist in Raphe nucleus, partial DA agonist: hallucinations
- flashbacks, anxiety, paranoia, psychosis
- irritable, anxiety
PCP
- mechanism
- effects
- toxicity
NMDA- receptor antagonist
- nystagmus, paranoia, rhabdomyolysis, super strength
- violent, coma, seizure, psychosis
