Cns stimulants
This presentation is the property of its rightful owner.
Sponsored Links
1 / 24

CNS STIMULANTS PowerPoint PPT Presentation


  • 107 Views
  • Uploaded on
  • Presentation posted in: General

CNS STIMULANTS. SAMUEL AGUAZIM. What is the definition of a CNS stimulant?. A CNS stimulant is a drug that increases motor activity, causes excitement and decreases feelings of fatigue. CNS stimulants include the methyxanthines, nicotine, and the amphetamines. CNS stimulant.

Download Presentation

CNS STIMULANTS

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Cns stimulants

CNS STIMULANTS

SAMUEL AGUAZIM


What is the definition of a cns stimulant

What is the definition of a CNS stimulant?

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

  • CNS stimulants include the methyxanthines, nicotine, and the amphetamines


Cns stimulant

CNS stimulant

  • PSYCHOMOTOR STIMULANTS

  • CAUSE EXCITEMENT & EUPHORIA

  • INCREASE MOTOR ACTIVITY

  • PSYCHOTOMIMETIC DRUGS

  • PROFOUND CHANGES IN THOUGHT PATTERNS AND MOOD

  • FEW DRUGS USED CLINICALLY

  • IMPORTANT AS DRUGS OF ABUSE


Methylxanthines

METHYLXANTHINES

  • What are methyxanthines? A group of psychomotor stimulants include:

  • Caffeine

  • Theophylline

  • Theobromine ( found in cocoa but of little interest)


How do methyxanthines work

How do methyxanthines work?

  • Research indicates that methyxanthines increases cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) by inhibiting phosphodiesterase and blocking adenosine receptors.


Caffeine

CAFFEINE

  • What are the physiologic effects of caffeine?

  • Caffeine effects a number of organ systems within the body:

  • CNS- caffeine increases motor activity and alertness

  • Cardiovascular- caffeine increases heart rate and contractility


Caffeine1

CAFFEINE

  • Smooth muscle- caffeine and its derivatives relax the smooth muscles of the bronchioles.

  • Genitourinary- caffeine can ac as weak diuretic and increase urinary output of Na+, CI- and K+

  • Gastrointestinal – caffeine stimulates secretion from the gastric mucosa. Therefore, patients who have peptic ulcer disease should be counseled to avoid caffeine


Adverse effects of chronic caffeine use

Adverse Effects of chronic caffeine use?

  • At low doses- insomnia and agitation can occur

  • At higher doses (8-10g)- Emesis, convulsion and even cardiac arrhythmias can occur.

  • Do methyxanthines cross the placenta?

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


Theophylline

THEOPHYLLINE

  • THERAPEUTIC ROLE OF THEOPHYLLINE:

  • It can be used in the treatment of asthma, but currently it is not being used frequently because it has a very narrow therapeutic index and is not effective as the new beta agonist


Nicotine

NICOTINE

  • How are the physiological effects of nicotine related to the dose?

  • In low doses, nicotine causes ganglionic stimulation by depolarization.

  • At high doses it causes ganglionic blockade


Nicotine1

NICOTINE

  • What are the physiologic actions of nicotine on the central nervous system?

  • At low doses- arousal, relaxation and improved attention

  • At high doses- central respiratory paralysis caused by disruption of medullary function


Nicotine2

NICOTINE

  • How does nicotine affect the peripheral nervous system?

  • At low doses- increase in blood pressure and heart rate; constriction of blood vessels to the digits and impairment of flow

  • At high doses- decrease in blood pressure and in action of GI and GU tract due to ganglionic blockade

  • NOTE: NICOTINE HAS NO THERAPEUTIC USES


Nicotine3

NICOTINE

  • What is nicotine’s route of administration?

  • Absorption occurs through oral mucosa by inhalation and transdermally.

  • What are its adverse effects?

  • CNS- irritability and tremors

  • Peripheral- intestinal cramps, diarrhea, and increased heart rate and blood pressure


Nicotine4

NICOTINE

  • What withdrawal symptoms do nicotine addicts experience?

  • A craving for tobacco is accompanied by irritability, restlessness, anxiety and gastrointestinal pain.


Amphetamines

AMPHETAMINES

  • Name three examples of this drug class.

  • 1. methylphenidate ( ritalin)

  • 2. methamphetamine ( methedrine)-”speed”

  • 3. dextroamphetamine ( dexedrine)


Amphetamines1

AMPHETAMINES

  • How do these drugs work?

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


Amphetamines2

AMPHETAMINES

  • What are the physiologic actions of these drugs?

  • Euphoria

  • Decrease in fatigue

  • Increase in blood pressure

  • Increase in rate of respiration

  • Decrease in appetite


Amphetamines3

AMPHETAMINES

  • What is their clinical use?

  • Attention deficit hyperactivity disorder(ADHD)-METHYLPHENIDATE is used to alleviate this problem

  • Appetite control- amphetamines decrease appetite by blocking the receptors in the lateral hypothalamus

  • Narcolepsy


Amphetamines4

AMPHETAMINES

  • What is the route of administration? Oral

  • Where are amphetamines metabolized? In the liver

  • Does physiologic and psychological dependence occur with amphetamine use?

  • Yes- amphetamines can be very addictive


Amphetamines5

AMPHETAMINES

  • What are the adverse effects of these drugs?

  • Amphetamines like caffeine and nicotine affects multiple organ systems.

  • CNS-insomnia, irritability, convulsions; chronic use can lead to a psychotic state resembling schizophrenia

  • Gastrointestinal- anorexia, nausea, dry motuh

  • Cardiovascular- palpitations, angina, arrhythmias, hypertension


Amphetamines6

AMPHETAMINES

  • Amphetamines are contraindicated with what group of drugs?

  • The monoamine Oxidase (MAO) inhibitors

  • How is amphetamine overdose managed?

  • Chlorpromazine is beneficial in amphetamine overdose because it blocks the alpha receptors which are responsible for the CNS disturbances and hypertension


  • Login