Licht: CNS Stimulants Flashcards
What are the CNS effects of sympathomimetics?
Behavioral:
- Decreased fatigue
- Increased: Wakefulness, confidence, motor/speech, speed in simple tasks
* hi doeses leads to restlessess/tremor
Other
- Stimulates medullary and respiratory centers
- Decrease food consumption
What are the non-CNS effects of sympathomimetics?
Non-CNS
- Increase systolic and diatstolic BP > decreased HR
- High dose > arrythmias
What do sympathomimetics do?
- Increase release of NE and DA
- Blocks NE and DA reuptake
- Inhibit MAO
What are the toxic affects of amphetamine?
Acute
CVS: HA, arrthymias, palpitations, anginal pain, hypterthermia
CNS: Dizziness, agitation, confusion, insomnia, seizures, coma
What is the treatment for acute toxicity or amphetamine overdose?
- Antipsychoctic
- Acidify the pts urine!
Giving htem ammonium chloride takes the urine from pH 5-2. Amphetamines are BASES. You give them an acid to IONIZE the drug so it CAN’T cross the plasma membrane and instead is secreted by urine.
What are the chronic toxic affects of amphetamines?
- Vivid hallucinations, paranoid delusions, compulsions
- marked weight loss
tx: Drug screen, symptoms usually resolve in 7-10 days
How are sympathomimetics therapeutically used?
Good uses:
ADHD, Narcolepsy
Bad uses:
Fatigue, weight loss, Analeptic
Which is more potent, cocaine or Amphetamine?
Cocaine!
1 mg cocaine = 10 mg amphetamine
What is the mechanism of Cocaine?
Blocks reuptake of NE- motor
Blocks reuptake of DA- euphoria
ALSO has local anesthetic properties
What are the toxic effects of cocaine?
- Cardia arrhythmias, coronary/cerebral thrombosis
- Impairs in utero brain development–> small brain and neurological problems
How is MMDA unique and unliek other amphetamines?
It has VERY rapid entry into the brain.
DIRECTLY stimulates 5HT2 autoreceptors
Stimulates the release of 5HT and inhibits reuptake.
Direclty affets other NTs like: histamine, GABA, ACh, DA receptors, binds to NE transport protein
What is the mechanism of MMDA (ecstasy)?
Stimulates release and inhibits uptake of:
E
NE
DA
What are bath salts?
Salts you commonly used in a bath!
Contain amphetamine-like chemicals: methylendioypyrovalerone, mephedrone (not DEA regulated drugs)
Why are bath salts bad?
They act in the brain like stimulant drugs!
Used as cocaine substitutes and present a high abuse and addiction liability.
AE: Chest pains, increased BP and HR, agitation, hallucinations, extreme paranoia, delusions
What are CNS efects for methylxanthines?
Stimulate the **cerebral cortex! **
Clear flow of thought, less fatigue, improved manual dexterity.
Stimulates the medullary centers–> increased respiration, and activates the vasomotor centetr.
Large doses–> spinal cord
What are the clincal uses of mehtylxanthines?
Cardiac stimulatin in CHF
Dilates coronary arteries
Increased blood flow
Increased O2 demand by heart
Ergot alkaloids for migraine
Bronchial asthma
Vasoconstriction of cerebral vasoculature
What are the adverse effects of methylxanthines?
CNS
Insomnia, excitement, mild delirium, sensory disturbances, convulsions
CVS
Increased HR, extra systoles, increased respiratory rate, decreased cloting time, increased gastric secretions
What is the mechanism of action of methylxanthines?
Translocation of Ca from SR
Inhibtion of phosphodiesterase
Elevated levels of second messenger cAMP
Non-selective adenosine receptor antagonist
inhibits sleepiness
What is the difference in tolerance between amphetamines, cocaine and caffeine?
Amphet: Tolerance effects appetite and mood
Cocaine: tolerance may develope, but some cocaine users can take the SAME dose EVERY day
Caffeine: Some users develop tolerance to sleep disturbing effects
What is the difference in dependence between Amphetamines, Cocaine and Caffeine?
Amphet: Mainly psychological though there is some evidence of physical dependence. Abrupt w/drawal leads to physical cravings, prolonged sleep, fatigue, excessive eating/depression
