Neuro drugs I

Question 1

How do opioid analgesics work?

Answer 1

act at mu opiod receptors. alter synaptic transmission by opening K channels and closing Ca2+ channels. this decreases synaptic transmission and inhibits the release of ACh, norepinephrine, 5-HT, glutamate, and substance P

Question 2

Apart from pain, what are some uses of opioids?

Answer 2

cough suppression (dextromethrophan), diarrhea treatment (loperamide), acute pulm edema

Question 3

How do you treat opioid toxicity?

Answer 3

naloxone or naltrexone, which are opioid receptor antagonists

Question 4

What is butorphanol?

Answer 4

this is a PARTIAL mu opiod receptor agonist. It is a kappa opioid receptor agonist. it produces anagesia but causes less resp depression than full opioid agonists. However, it can cause opioid withdrawal in a patient who is also taking a full opioid agonist, and can’t be easily reversed with naloxone

Question 5

What should I know about opioid receptor types?

Answer 5

mu: morphine
delta: enkaphalin
kappa: dynorphin

Question 6

What is the mechanism and toxicities for tramadol?

Answer 6

weak opiod agonist. also inhibits serotonin and NE reuptake. good for chronic pain. toxicities: decreases seizure threshold and can cause serotonin syndrome

Question 7

How do barbiturates work?

Answer 7

facilitate GABA action by increasing the DURATION of Cl channel opening. neuron firing decreases.

Question 8

Toxicities and contraindications of barbiturates?

Answer 8

contraindicated in porphyria. can cause respiratory and CV depression

Question 9

How do benzodiazepines work?

Answer 9

facilitate GABA-A action by increasing the frequency of Cl channel opening. decreases REM sleep. many have long half-lives and active metabolites (but not triazolam, oxazeam, midazolam- so these three have greater addictive potential)

Question 10

Which benzos are used for status epilepticus?

Answer 10

lorezepam and diazepam

Question 11

How do you treat benzo toxicity?

Answer 11

flumazenil (competitive antagonist at the GABA benzo receptor)

Question 12

What are the non-benzodiazepine hypnotics and how do they work? treatment of toxicity?

Answer 12

zolpidem (ambien), zaleplon, (eszopiclone)
work by binding the BZ1 subtype of GABA receptor, and may be reversed by flumazenil
used for insomnia

Question 13

What are the inhaled anesthetics and what is a major complication? Effect on blood flow to the brain?

Answer 13

halothane, enflurane, methoxyflurane, nitrous oxide, among others. increase cerebral blood flow
all but nitrous oxide can cause malignant hyperthermia- inhaled anesthetics and succinylcholine induce fever and muscle contractions.

Question 14

Thiopental: class, uses, effect on blood flow

Answer 14

highly potent, high lipid solubility, rapid entry to bran. used for induction of anesthesia and short procedures. decreases cerebral blood flow. effect terminated by rapid redistribution to the tissues

Question 15

Midazolan: class, uses

Answer 15

most common drug for endoscopy. may cause severe post-op resp depression, decrease BP (treat OD with flumazenil), and anterograde amnesia

Question 16

Ketamine: class, function, effect on blood flow

Answer 16

PCP analogues. block NMDA receptors. act as CV stimulants. cause disorientation, hallucination, and bad dreams. increase cerebral blood flow

Question 17

What is propofol? uses, MOA

Answer 17

used for sedation in ICU, rapid anesthesia induction, and short procedures. less post-op nausea than thiopental. potentiates GABA-A