Drugs Affecting The CNS

Question 1

What are the drugs that effect the CNS? And how it affects it?

Answer 1

Sedative drugs, these drugs exert their effects by interacting with neurotransmissions, by effecting neurotransmitter release, metabolism, uptake or by acting at primary or modifying receptors, or transport proteins.
To sum up,
Release
Metabolism
Uptake
Action at receptor site
Transport protein

Question 2

What are the clinical effect of CNS drug?

Answer 2

Depends on the localization of specific neurotransmitters in specific brain areas.

Question 3

What is the main side effect of CNS drugs?

Answer 3

CNS is complex, main cause of the side effect of CNS drug is their interaction in diffuse brain areas.

Question 4

What are clinical & side effects of CNS drugs?

Answer 4

Function
Mood
Perception of pain
Anxiety
Sleep
Memory

Question 5

What is anxiolytics?

Answer 5

They are minor tranquilizers. These drugs are used to treat anxiety disorders and insomnia. Most common class of anxiolytics is benzodiazepines.

Question 6

Which is the most common class of anxiolytics?

Answer 6

Most common class of anxiolytics is benzodiazepines.

Question 7

What is the indication of anxiolytics (benzodiazepines)?

Answer 7

Outpatient and inpatient.
Outpatient includes daily or sporadic anxiety.
Inpatient includes pre-procedure for anxiety, procedural sedation and amnesia, terminate seizures or increase threshold.

Question 8

Drug name for anxiolytics (benzodiazepines)

Answer 8

Outpatient-
alprazolam
Diazepam
Lorazepam
Inpatient
Midazolam- IV- GIVEN FOR SEDATION, remember we are talking about CNS sedative drugs.

Question 9

Specific antagonist for benzodiazepines?

Answer 9

Flumazenil- to reverse overdose.

Question 10

What is the MOA for Benzodiazepines?

Answer 10

1. Depress the nerve synapse in RAS
2. Bind to receptors within GABA complex on the neuron.
   3.increase chloride channel permeability leading to hyperpolarization(lack of repolarization
3. Results in decrease or inhibits neurotransmission or decrease neuronal function.

Question 11

What is the side effect of benzodiazepines?

Answer 11

Decrease consciousness and psychosis

Question 12

Which drug is widely replaced with benzodiazepines?

Answer 12

Barbiturates.
It depress the neuron activity, but has high risk of addiction and abuse.

Question 13

What are analgesics?

Answer 13

Drugs that provide pain relief. It can be subdivided into narcotics and non-narcotics.

Question 14

How is pain experience based on?

Answer 14

1. Pain sensation- input from the CNS pain receptors
2. Suffering- Negative emotional response to pain.

Question 15

What are the types of pain?

Answer 15

1.Nociceptive pain-tissue damage
Pain arising from the stimulation of nerve cells due to thermal(hot pan), chemical(spicy chicken) or mechanical stimulation(dropping of pan on your toe).

2. Neuropathic pain- nerve pain
   Damage or disease affecting any part of nervous system
   Peripheral neuropathic pain is the burning, tingling or pins and needles(neuropathy)
3. Psychogenic- pain caused, increased or prolonged by mental, emotional or behavioral factors

Question 16

Name the 3 categories under analgesics/anti-pyretics

Answer 16

NSAIDS, Opioids, Local anesthetics.

Question 17

What is the MOA for NSAIDS(Aspirin, parasol, ibrufen)?

Answer 17

1. Inhibits inflammatory mediators(prostaglandins, cyclooxygenase) at peripheral pain stimulus (reduces pain and inflammation).
2. Inhibit production of pyrogens to prevent adjustment of body temperature in the hypothalamus (reduced fever)
3. Inhibit breakdown of arachidonic acid.

Question 18

What is the indication for Aspirin/ acetylsalicylic acid?

Answer 18

Anti-inflammatory- to reduce inflammation
Anti-pyretic- to reduce pain
Analgesic-
Anti-platelet (baby dose)

Question 19

Side effect of Aspirin?

Answer 19

Caution with asthmatics- samters syndrome
Caution with ulcers/GI bleed- most common
Caution with children- Reye’s syndrome
Overdose= metabolic acidosis due to kussmaul breathing

Question 20

What is indication for acetaminophen/parasol/tylenol?

Answer 20

Anti-pyretic(for fever)
Analgesic(for pain)

Question 21

What is the category of acetaminophen?

Answer 21

Aniline derivatives

Question 22

What are the side effects of acetaminophen?

Answer 22

Minimal to no anti inflammatory or anti platelet action

Question 23

What does drug overdose lead to when taking acetaminophen?

Answer 23

It means panadol, it leads to hepatic toxicity.

Question 24

What is indication for ibrufen and naproxen?

Answer 24

Anti-inflammatory
Analgesic
Anti-pyretic

Question 25

What are the side effects of ibrufen and naproxen?

Answer 25

Gastric irritation Caution with asthmatics Less tolerated than paracetamol and has higher drug interaction

Question 26

Ibrufen and naproxen is what derivative?

Answer 26

Propionic acid derivative

Question 27

What are Opiods/analgesics?

Answer 27

They are narcotics derived from opium.

Question 28

Name endogenous and exogenous opiods

Answer 28

Endogenous- endorphins and enkephalins Exogenous(narcotics)- opium

Question 29

Indication for opioids

Answer 29

For Moderate to severe pain Used along balanced anesthetics(paired with a muscle relaxant and induction agent)

Question 30

ROA for opiods

Answer 30

IV (Peripheral, PCA and epidural), topical, PO, Inhalation

Question 31

MOA for opiods

Answer 31

1. Act on the opioids receptors in the brain, spinal cord, some other areas to close calcium channels 2. Creates hyperpolarization 3. Decreases neuronal cell excitability 4. Reduces transmission of impulses related to pain but cause CNS depressing effects.

Question 32

what is morphine/analgesics?

Answer 32

Main therapeutic use is analgesics, sedation(balanced anesthesia or combination), vasodilator (MI, CHF)

Question 33

What are the main side effects of Morphine?

Answer 33

Histamine release- asthma Hypotension Emesis(vomiting) Constipation Respiratory depression

Question 34

What is fentanyl?

Answer 34

Main therapeutic use is • fentanyl is synthetic derivative of Morphine so similar uses • 80-100 times the potency of morphine(strong) • Shorter half life than morphine (huge benefit) • Chest rigidity may occur affecting ventilation prior to intubation

Question 35

Antagonist for narcotics

Answer 35

Naloxone, is a narcotic antagonist that competes with narcotics at opioid receptors, has high affinity but no efficacy. It’s therapeutic use is to reverse the unintended respiratory depression

Question 36

ROA for Naloxone

Answer 36

IV, TOPICAL through nares for immediate response, IM for sustained.

Question 37

What is indication of Local anesthetics?

Answer 37

• localized pain control (stiches, cyst removal, dental procedures) • Epinephrine often added for vasoconstriction, slowing absorption • terminating cardiac conduction abnormalities • suppress irritant tracheal cough response (bronchoscopy and others)

Question 38

MOA for local anes

Answer 38

Interrupt nerve signals (pain) from damaged area by blocking Na+ channels along nerve cells

Question 39

Drug name for local anes

Answer 39

Lidocaine, also given in inhalation/nebulization form to suppress gag in bronchoscopy

Question 40

Indication for epidural anes

Answer 40

Birth, awake surgery or post surgical pain control. It comprises of local anes + opioid+ combo anes= injected or infused into the epidural space.

Question 41

Side effect of epidural

Answer 41

Reduced or eliminated feeling Spinal damage

Question 42

What are IV anesthetics(white milk)

Answer 42

They are used to induce anesthesia or absence of perception, they are dose dependent, they are combined with analgesics and muscle relaxant in critical care. They can be used short term- bolus when intubation, procedural or conscious sedation, or long term- infusion to maintain anesthesia when on MV for instance.

Question 43

Benzodiazepines & Barbiturates “ can” be considered induction agents, but they are not commonly used for IV anesthetics or as induction agents. True or false

Answer 43

True, Midazolam are considered induction agents but not commonly used.

Question 44

Why is IV anesthetics given?

Answer 44

They are inducing anesthesia, when during procedure. Half life is short. Sedation is minimal(short half life), moderate, and deep (quick).

Question 45

Key comparison between etomodate, propofol and ketamine.

Answer 45

All of them are for sedations: Etomodate: also given for hypotension but not better than ketamine, however it is better than propofol. It reduces seizure threshold(side effect) Propofol: stops seizure, cerebral protective. vasodilation, reduces C.O and reduces BP, pain at the site of injection are all side effects. Ideal situation: status epilepticus. Ketamine: only sedative which is sympathomimetics. Therefore, increases heart rate, BP and bronchodilation. Ketamine is given for severe hypotension patients to put them to sleep. Increases ICP. Causes hallucinations. Ideal situation: status asthmatics, anaphylaxis. Side effects: dissociative state, increase ICP, so shud be not be given to Hypertensive patient.