Convulsants / Stimulants Flashcards Preview

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Flashcards in Convulsants / Stimulants Deck (39):
1

What are convulsants used for?

  • Provacative diagnosis of epilepsy
  • Keeps people awake as well 

2

What drugs can we use as convulsants?

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

3

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

strychnine

4

What are stimulants used for?

As an antidote for depression = "analeptics"

no one drug is very effective

Primarily used to reverse respiratory, cardiac and CNS depression

5

What are the primary classes of stimulants?

  • Xanthenes
  • Sympathomimetics (centrally acting)
  • Convulsants

6

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

Xanthenes

  • Theophylline
  • Aminophylline
  • Caffeine

7

What are the pharmacologic effects of xanthenes?

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

8

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

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

9

What are some of the effects of xanthenes?

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

10

What is more potent theophylline or caffeine?

Theophylline

11

What do xanthenes do to cardiac muscle?

Increase the output, stimulation (Beta 1)

12

Does caffeine cause hypertension or hypotension?

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

13

What do xanthenes do to smooth muscles?

Relaxation (beta2), bronchial dilation

 

14

What xanthene is a popular asthma medication?

Theophylline

15

What can caffeine do to skeletal muscles?

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

16

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

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


  • CNS - caffeine = theophylline 



  • BloodVolume - theophylline


  • Heart - theophylline 




  • Smooth muscles - theophylline 






  • Skeletal muscles - caffeine 








  • Diuresis - theophylline











     

17

What are the 3 ways xanthenes act as diuretics?

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

18

What are the adverse reactions of xanthenes?

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

19

What dose of caffeine is required to produce toxicity?

300 mg (6 cups of tea)

20

How much caffeine a day produces physical dependence?

600 mg/day > 6 cups of coffee

21

When does withdrawal syndrome begin with caffeine?

within 24 hours of discontinuance

headahce, lethargy, irritability, anxiety

Tolerance develops

22

What are the therapeutic uses of xanthenes?

  • 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

23

What's the mechanism of action for amphetamines?

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

24

What type of drug are amphetamines?

CNS sympathomimetics

25

What effects do CNS sympathomimetics have?

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

26

What are the indications/therapeutic use of CNS sympathomimetics?

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

27

What are the adverse effects of CNS sympathomimetics?

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

28

What's the mechanism of action for cocaine?

  • 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

29

What does cocaine do?

Increases peripheral resistance, increases cardiac output, energy expenditure

30

What types of drugs are there for ADHD?

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

31

How does Ritalin work?

Blocks reuptake of dopaminergive neurons, avoid vasoconstrictors

32

How does Dexadrine work?

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

33

How does atomoxetine (Straterra) work?

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

use vasoconstrictor with caution

34

What is ephedrine (Pretz-D) used for?

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

35

Which amphetamines have been pulled from the market?

  • 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

36

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

Administering local anesthetics with vasoconstrictors 

37

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

doxapram (Dopram)

38

What is one of the most addicting substances known?

Nicotine

39

What do low/high doses of nictone do?

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