Ch 17 - CNS Stimulants - DONE

Question 1

What is the definition of CNS stimulants?

Answer 1

A CNS stimulant is a drug that increases motor activity, causes excitement, and decreases the feelings of fatigue.

Question 2

Give examples of CNS stimulants:

Answer 2

• Methylxanthine
• Nicotine
• Amphetamine

Question 3

What are Methylxanthines?

Answer 3

A group of psychomotor stimulants including:

• Caffeine
• Theophylline
• Theobromine (found in cocoa)

Question 4

How do Methylxanthines work?

Answer 4

Methylxanthines increase cGMP and cAMP by inhibiting phosphodiesterase and blocking adenosine receptors

Question 5

What are the physiological effects of caffeine?

CNS

Answer 5

Caffeine increases motor activity and alertness

Question 6

What are the physiological effects of caffeine?

Cardiovascular

Answer 6

Caffeine increase the heart rate and contractility

Question 7

What are the physiological effects of caffeine?

Smooth muscle

Answer 7

Caffeine and its derivatives relax the smooth muscle of the bronchioles

Question 8

What are the physiological effects of caffeine?

Genitourinary

Answer 8

Caffeine can act as weak diuretics and increase urinary output of Na+, Cl-, and K+

Question 9

What are the physiological effects of caffeine?

GI

Answer 9

Caffeine stimulates secretion of HCL from the gastric mucosa. Therefore patients who have peptic ulcer disease should be counseled to avoid caffein

Question 10

What are the adverse effect of chronic use of caffeine?

Answer 10

• at low doses: insomnia and agitation can occur

- at higher doses: emesis, convulsion, and even cardiac arrhythmias can occur

Question 11

Do the Methylxanthines cross the placenta?

Answer 11

Yes, and they are secreted into the mother´s milk. Patients should be advised to avoid them during pregnancy and while nursing.

Question 12

What is the therapeutic role of Theophylline?

Answer 12

Theophylline can be used in the treatment of asthma, but currently it is not being frequently used because it has a very narrow therapeutic index and is not as effective as the new β agonists

Question 13

How are the physiological effect of nicotine related to the dose?

Answer 13

• low doses: nicotine causes ganglionic stimulation by depolarization
• high doses: nicotine causes ganglionic blockade

Question 14

What are the physiologic actions of nicotine on the CNS at low doses?

Answer 14

• arousal
• relaxation
• improved attention

Question 15

What are the physiologic actions of nicotine on the CNS at high doses?

Answer 15

central respiratory paralysis caused by disruption of medullary function

Question 16

How does the nicotine affect the peripheral nervous system at low doses?

Answer 16

• increase in BP and HR

- constriction of blood vessels to the digits and impairment of flow

Question 17

How does the nicotine affect the peripheral nervous system at high doses?

Answer 17

decrease in BP and in action of GI and GU tract due to ganglionic blockade

Question 18

GU tract =

Answer 18

genitourinary tract

Question 19

What are nicotine´s therapeutic use?

Answer 19

As an ingrediant of a transdermal patch or chewing-gum, low-dose nicotine is used to help with smoking cessation

Question 20

Name three amphetamines:

Answer 20

1. methylphenidate
2. methamphetamine
3. dextroamphetamine

Question 21

How do amphetamine work?

Answer 21

Amphetamines work by releasing neuronal stores of catecholamines, especially norepinephrine and dopamine

Question 22

What are the physiological action of amphetamine?

Answer 22

• euphoria
• decrease in fatigue
• increase in BP
• increase in rate of respiration
• decrease in appetite

Question 23

What is the clinical use of amphetamine?

Answer 23

• ADHD
• Appetite control
• Narcolepsy

Question 24

What is used to treat ADHD?

Answer 24

methylphenidate (an amphetamine)

Question 25

What is used to control the appetite?

Answer 25

Amphetamines decrease appetite by blocking the receptors in the lateral hypothalamus

Question 26

What is used to treat narcolepsy?

Answer 26

Amphetamines

Question 27

What is the route of administration of Amphetamines?

Answer 27

oral

Question 28

where are Amphetamines metabolised and excreted?

Answer 28

- metabolised in the liver | - excreted in the urine

Question 29

Does physiological and psychological dependence occur with Amphetamines use?

Answer 29

Yes, Amphetamines can be very addictive

Question 30

Amphetamines AE: | CNS

Answer 30

- insomnia - irritability - convulsions - chronic use can lead to a psychotic state resembling Schizophrenia

Question 31

Amphetamines AE: | GI

Answer 31

- anorexia - nausea - dry mouth

Question 32

Amphetamines AE: | Cardiovascular

Answer 32

- palpitations - angina - arrhythmias - hypertension

Question 33

With what group of drugs are Amphetamines CI with?

Answer 33

The monoamine oxidase (MAO) inhibitors

Question 34

How is Amphetamines overdose managed?

Answer 34

Chlorpromazine in beneficial in Amphetamines overdose because it blocks the α receptors which are responsible for the CNS disturbances and hypertension