Analgesic, Sedative and Anesthetic Pharmacology

Question 1

What is the mechanism of opioid analgesics?

Answer 1

Act as agonists at opioid receptors to modulate synaptic transmission (open K+ channels, close Ca²⁺ channels to decrease synaptic transmission)

Inhibit release of ACh, NE, 5-HT, glutamate and substance P

Question 2

Clinical use of opioid analgesics

Answer 2

Pain

Acute pulmonary edema

Question 3

Which opioid class drug is used for cough suppression?

Answer 3

Dextromethorphan

Question 4

Which opioids are used for diarrhea?

Answer 4

Loperamide

Diphenoxylate

Question 5

Which opioid is used for maintenance programs for addicts?

Answer 5

Methadone

Question 6

Toxicity of opioids

Answer 6

Addiction

Respiratory depression

Constipation

Miosis

Additive CNS depression with other drugs

Tolerance does not develop to miosis and constipation

Question 7

Tx for opioid toxicity

Answer 7

Naloxone

Naltrexone

Opioid receptor antagonists

Question 8

Mechanism of butorphanol

Answer 8

Mu-opioid receptor PARTIAL agoinst and kappa-opioid receptor agonist

Question 9

Clinical use of butorphanol

Answer 9

Severe pain (migraine, labor, etc)

Causes less respiratory depression than full opioid agonists

Produces analgesia

Question 10

Toxicity of butorphanol

Answer 10

Can cause opioid withdrawal symptoms if patient is also taking full opioid agonist (competition for opioid receptors)

Overdose not easily reversed with naloxone

Question 11

Mechanism of tramadol

Answer 11

Very weak opioid agonist

Also inhibits serotonin and NE reuptake (works on multiple neurotransmitters – "tram it all" in with tramalol)

Question 12

Clinical use of tramadol

Answer 12

Chronic pain

Question 13

Toxicity of tramadol

Answer 13

Similar to opioids

Decreases seizure threshold

Question 14

Mechanism of phenytoin

Answer 14

Use-dependent blockade of Na+ channels; inhibition of glutamate release from excitatory presynaptic neurons

Question 15

Clinical use of phenytoin

Answer 15

Tonic-clonic seizures

Also a class 1B antiarrhythmic

Question 16

Toxicity of phenytoin

Answer 16

Nystagmus

Diplopia

Sedation

SLE-like syndrome

Induction of Cyt P-450

Chornic use produces gingival hyperplasia, peripheral neuropathy, hirsutism, and megaloblastic anemia

Teratogenic

Question 17

What class of drugs are phenobarbital, pentobarbital, thiopentla and secobarbital?

Answer 17

Barbiturates

Question 18

Mechanism of phenobarbital, pentobarbital, thiopentla and secobarbital (barbiturates)?

Answer 18

Facilitate GABA^A action by increasing duration of Cl^- channel opening

Thus decreases neuron firing

Question 19

Contraindication for phenobarbital, pentobarbital, thiopentla and secobarbital (barbiturates)?

Answer 19

Porphyria

Question 20

Clinical use of phenobarbital, pentobarbital, thiopentla and secobarbital (barbiturates)?

Answer 20

Sedative for anxiety

Seizures

Insomnia

Question 21

Which barbiturate is used for induction of anesthesia?

Answer 21

Thiopental

Question 22

Toxicity of phenobarbital, pentobarbital, thiopentla and secobarbital (barbiturates)?

Answer 22

Respiratory and cardiovascular depression (can be fatal)

CNS depression

Dependence

Drug interactions (induces P-450)

Question 23

Tx for phenobarbital, pentobarbital, thiopentla and secobarbital (barbiturates) overdose

Answer 23

Overdose treatment is supportive (assist respiration and maintain BP)

Question 24

Mechanism of benzodiazepines

Answer 24

Facilitate GABAA action by increasing frequency of Cl^- channel opening

Decrease REM sleep

Most have long half lives and active metabolites

Question 25

Clinical use of benzodiazepine

Answer 25

Anxiety spasticity Detoxification (esp alcohol withdrawals) Night terrors Sleepwalking General anesthetic Hypnotic

Question 26

Toxicity of benzodiazepine

Answer 26

Dependence Additive CNS depression effects with alcohol Less risk of respiratory depression and coma than with barbiturates

Question 27

Tx of benzodiazepine overdose

Answer 27

Flumazenil (competitive antagonist at GABA benzodiazepine receptor)

Question 28

Which benzodiazepine drugs are used for status epilepticus?

Answer 28

Lorazepam Diazepam

Question 29

What drug class do these belong to? Midazolam Chlordiazepoxide Alprazolam

Answer 29

Benzodiazepine

Question 30

What class of drugs are these? Zolpidem Zaleplon Eszopiclone

Answer 30

Nonbenzodiazepine hypnotics

Question 31

Mechanism of Nonbenzodiazepine hypnotics

Answer 31

Act via BZ1 receptor subtype of the GABA receptor

Question 32

Clinical use of Nonbenzodiazepine hypnotics

Answer 32

insomnia

Question 33

Toxicity of Nonbenzodiazepine hypnotics

Answer 33

Ataxia Headaches Confusion Short duration because of rapid metabolism by liver enzymes Unlike older sedative-hypnotics, cause only modest-after psychomotor depression and few amnestic effects Lower dependence risk than benzodiazepine

Question 34

What class of drugs is halothane, enflurance and isoflurane?

Answer 34

Inhaled anesthetics

Question 35

What class of drugs is methoxyflurane and nitrous oxide?

Answer 35

Inhaled anesthetic

Question 36

Mechanism of inhaled anesthetics

Answer 36

Mechanism unknown

Question 37

Effects of inhaled anesthetics

Answer 37

Myocardial depression Respiratory depression Nausea/emesis Increased cerebral blood flow (decreased cerebral metabolic demand)

Question 38

Toxicity of inhaled anesthetics

Answer 38

Malignant hyperthermia (all but nitrous oxide; inherited suceptibility)

Question 39

Toxicity of halothane

Answer 39

Hepatotoxicity

Question 40

Toxicity of methoxyflurane

Answer 40

Nephrotoxicity

Question 41

Toxicity of enflurane

Answer 41

Proconvulsant

Question 42

Toxicity of nitrous oxide

Answer 42

Expansion of trapped gas in a body cavity

Question 43

What are 5 classes of IV anesthetics?

Answer 43

Barbiturates Benzodiazepines Arylcyclohexylamines (Ketamine) Opioids Propofol "BB King on OPIOIDS PROPOses FOOLishly"

Question 44

Which barbiturate is used as an IV anesthetic and describe its kinetics?

Answer 44

Thiopental High potency (high lipid solubility) Rapid entry into brain

Question 45

What is the use of thiopental in IV anesthetic? How are its effects terminated

Answer 45

Used for induction of anesthesia and short surgical procedures Effects terminated by rapid redsitribution into tissue and fat

Question 46

Which benzodiazepine is most often used for endoscopy?

Answer 46

Midazolam

Question 47

What other drugs must benzodiazepines be used with for IV anesthetic?

Answer 47

Used adjunctively with gaseous anesthetics and narcotics

Question 48

Toxicity of benzodiazepine use in IV anesthetics?

Answer 48

May cause severe post-op respiratory depression, decreased BP and amnesia

Question 49

What is ketamine a derivative of?

Answer 49

PCP analog

Question 50

What is the clinical use of ketamine?

Answer 50

Dissociative anesthetic Cardiovascular stimulant

Question 51

Mechanism of ketamine

Answer 51

Block NMDA receptors

Question 52

Use of opioids in IV anesthetic

Answer 52

Used with other CNS depressants during general anesthesia

Question 53

What are propofol anesthetic uses?

Answer 53

Sedation in ICU Rapid anesthesia induction Short procedures

Question 54

Mechanism of propofol

Answer 54

Potentiates GABA^A

Question 55

What are the two classes of local anesthetics?

Answer 55

Esters (procaine, cocaine, tetracaine) Amides (amides have two I's in their name; i.e. lidocaine, mepivacaine, etc)

Question 56

Mechanism of local anesthetics

Answer 56

Block Na channels by binding to specific receptors on inner portion of channel Preferentially binds to activated Na channels so most effective in rapidly firing neurons Tertiary amine local anesthetics penetrate membrane in uncharged form then bind to ion channels as charged form

Question 57

Clinical use of local anesthetics

Answer 57

Minor surgical procedures Spinal anesthetic

Question 58

Toxicity of local anesthetics

Answer 58

CNS excitation Severe cardiovascular toxicity (bupivacaine) HTN Hypotension Arrhythmias (cocaine)