Convulsants / Stimulants

Question 1

What are convulsants used for?

Answer 1

• Provacative diagnosis of epilepsy
• Keeps people awake as well

Question 2

What drugs can we use as convulsants?

Answer 2

• pentylenetetrazole (Metrazole)
• strychnine - rat poison
• picrotoxin

Question 3

What rat poison convulsant is added to heroin and causes overdose?

Answer 3

strychnine

Question 4

What are stimulants used for?

Answer 4

As an antidote for depression = “analeptics”

no one drug is very effective

Primarily used to reverse respiratory, cardiac and CNS depression

Question 5

What are the primary classes of stimulants?

Answer 5

• Xanthenes
• Sympathomimetics (centrally acting)
• Convulsants

Question 6

What stimulants are used for asthma, chronic bronchitis and COPD?

Answer 6

Xanthenes

• Theophylline
• Aminophylline
• Caffeine

Question 7

What are the pharmacologic effects of xanthenes?

Answer 7

• 50-200 mg of caffeine or theophylline is needed to increase cortical activity
• OTC stimulants have 100-200 mg

Question 8

What is the order of potency of xanthenes in their locations?

Answer 8

• Cerebral cortex - 50-200 mg
• Brain stem - >250 mg
• Spinal cord = 1000 mg can lead to convulsions, shakiness

Question 9

What are some of the effects of xanthenes?

Answer 9

• Blood vessel dilation (Beta 2 effect)
• Dilation - coronary and peripheral blood vessels
• Constriction - cerebral blood vessels (treatment for headache)

Question 10

What is more potent theophylline or caffeine?

Answer 10

Theophylline

Question 11

What do xanthenes do to cardiac muscle?

Answer 11

Increase the output, stimulation (Beta 1)

Question 12

Does caffeine cause hypertension or hypotension?

Answer 12

Hypotension - normal heart rate, will cause arrhythmias in someone who is at risk, not in normal heart

Question 13

What do xanthenes do to smooth muscles?

Answer 13

Relaxation (beta2), bronchial dilation

Question 14

What xanthene is a popular asthma medication?

Answer 14

Theophylline

Question 15

What can caffeine do to skeletal muscles?

Answer 15

Cause contractions - pain stiffness, pyschic tension in neck –> headaches

Question 16

What is more potent in the following, Theophylline or Caffeine?

• CNS
• Blood Volume
• Heart
• Smooth muscles
• Skeletal muscles
• Diuresis

Answer 16

• CNS - caffeine = theophylline
• BloodVolume - theophylline
• Heart - theophylline
• Smooth muscles - theophylline
• Skeletal muscles - caffeine
• Diuresis - theophylline

Question 17

What are the 3 ways xanthenes act as diuretics?

Answer 17

1. Increased GFR
2. Inhibits ADH
3. Increased perfusion to kidney

Question 18

What are the adverse reactions of xanthenes?

Answer 18

• CNS - dizziness, convulsions
• GI - nausea & vomiting
• CVS - hypotention, palpitations
• Habit forming

Question 19

What dose of caffeine is required to produce toxicity?

Answer 19

300 mg (6 cups of tea)

Question 20

How much caffeine a day produces physical dependence?

Answer 20

600 mg/day > 6 cups of coffee

Question 21

When does withdrawal syndrome begin with caffeine?

Answer 21

within 24 hours of discontinuance

headahce, lethargy, irritability, anxiety

Tolerance develops

Question 22

What are the therapeutic uses of xanthenes?

Answer 22

• Asthma
• Chronic bronchitis
• COPD
• Status asthmaticus - life threatening asthma attach
• Maintains wakefulness
• Migraines
• Some CNS depressent poisonings - opioids
• Acute pulmonary edema and apnea in preterm infants
• Diuretic

Question 23

What’s the mechanism of action for amphetamines?

Answer 23

• Direct alpha-1 or dopamine receptor agonists
• MAO inhibitors
• Re-uptake inhibitors
• Presynaptic releasers of endogenous catecholamines

Question 24

What type of drug are amphetamines?

Answer 24

CNS sympathomimetics

Question 25

What effects do CNS sympathomimetics have?

Answer 25

* **Decrease fatigue** * Wakefulness * Physical performance * Reduced REM sleep

Question 26

What are the indications/therapeutic use of CNS sympathomimetics?

Answer 26

* **Narcolepsy** - only good therapeutic indication * **Hyperkinetic syndromes** - ADD/ADHD * Abnormal electrical activity, helps reduce behavior problems/concentration

Question 27

What are the adverse effects of CNS sympathomimetics?

Answer 27

* **Acute toxicity** - irritability, insomnia, xerostomia, nausea, palpitations, sweating * **Chronic toxicity** - psychosis resembling paranoid schizophrenia * **Dependency/addiction**

Question 28

What's the mechanism of action for cocaine?

Answer 28

* Blocks sodium/potassium ATP-ase reuptake mechanism * Dopamine and NE remains in synapse * Crosses blood brain barrier, increases sympathetic effects * **Causes euphoria once reaches CNS**

Question 29

What does cocaine do?

Answer 29

Increases peripheral resistance, increases cardiac output, energy expenditure

Question 30

What types of drugs are there for ADHD?

Answer 30

* Adrenergic agonists = CNS stimulation * methylphenidate (Ritalin) * Stimulants * dextroamphetamine (Dexadrine) * Selective Norepinephrine Reuptake Inhibitor * atomoxetine (Straterra)

Question 31

How does Ritalin work?

Answer 31

Blocks reuptake of dopaminergive neurons, avoid vasoconstrictors

Question 32

How does Dexadrine work?

Answer 32

Blocks the reuptake of dopamine and norepinephrine - inhibits monamine oxidase, avoid vasoconstrictor

Question 33

How does atomoxetine (Straterra) work?

Answer 33

Selectively inhibits reuptake of norepinephrine with little to no activity at other reuptake or receptor sites use vasoconstrictor with caution

Question 34

What is ephedrine (Pretz-D) used for?

Answer 34

It's an amphetamine for cough and cold medications to relieve bronchial and nasal congestion

Question 35

Which amphetamines have been pulled from the market?

Answer 35

* **phenylpropanolamine (PPA)** - appetite suppressants (OTC diet pills), deaths from heart attack and stroke * **ephedra** - used to be OTC diet pills, deaths from heart attach and stroke, stimulants for performance enhancement

Question 36

What do you have to be aware/cautious about with patients using amphetamines?

Answer 36

Administering local anesthetics with vasoconstrictors

Question 37

What stimulant is sold as parenteral drug to reverse general anesthesia or drug-induced respiratory depression?

Answer 37

doxapram (Dopram)

Question 38

What is one of the most addicting substances known?

Answer 38

Nicotine

Question 39

What do low/high doses of nictone do?

Answer 39

* Low: from smoke stimulates nicotinic receptors in brain stem and cortex * High: causes convulsions, which can be fatal