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Flashcards in CNS Stimulants Deck (26):
1

Main clinical uses of CNS Stimulants

ADHD and Narcolepsy

2

Methylxanthine, competitive antagonist of Adenosine receptors

Caffeine

3

What does caffeine inhibit at higher doses?

cAMP Phosphodiesterase --> increases cAMP, induces the release of Ca from intracellular stores (responsible for benefit to asthmatics)

4

Pharmacological actions of caffeine

CNS stimulant: increases alertness, attention, decreases fatigue/drowsiness, can cause nervousness, restlessness, tremors, at high doses stimulates medullary respiratory and CV centers, can get tachycardia Peripheral effects: Positive inotropic and chronotropic on myocardium, dilates coronary/systemic bv, constricts cerebral bv, diuretic, increases gastric secretions, modest bronchodilation

5

Weak base, potent inhibitor of reuptake of NE, serotonin and dopamine

Cocaine

6

What is cocaine's specific mechanism of action?

Binds transporter itself and inhibits the binding of ntm --> reinforcing effects from increased dopamine in synapse; Also increases activity of tyrosine and tryptophan hydroxylases

7

What are the pharmacological effects of cocaine?

1. Peripheral sympathomimetic effects --> Vasoconstriction, tachycardia 2. Increase alertness/vigilance 3. Euphoria, elation, feeling of well-being --> d/t inhibition of Dopamine reuptake in the mesolimbic circuit (high abuse liability)

8

Toxic Effects of Cocaine

Tolerance/physical dependence Mild withdrawal symptoms Neurotoxicologic effects d/t damage of dopaminergic neurons OD --> seizures, CV effects Effects developing fetus Profound psychological dependance

9

Therapeutic use of cocaine

Local anesthetic in URT, also decreases BF

10

Structurally similar to NE, weak bases, well-absorbed orally, metabolized to benzoic acid and excreted unchanged, relatively long 1/2 life

Amphetamine and Methamphetamine

11

Mechanism of action of Amphetamines

1. Release NE, DA and 5-HT from neurons 2. Block reuptake of NE, DA and 5-HT 3. Partial agonist of alpha-receptors 4. MAOI at high doses

12

Pharmacological Properties of Amphetamines

Arousal, wakefulness, decreased fatigue; Enhance athletic/intellectual performance; Elevated mood, increased self-confidence; Respiratory stimulant, decreases appetite, peripheral sympathomemetic

13

Clinical uses of amphetamines

ADHD, Narcolepsy

14

Side Effects of amphetamines

Insomnia, abdominal pain, anorexia, weight loss, suppression of growth, high body temp, facial tics

15

Mixture of stereoisomiers; active form is dextroamphetamine

Amphetamine

16

Not technically an amphetamine but structurally and mechanistically simliar

Methylphenidate

17

Gets into brain better; higher abuse liability

Methamphetamine

18

Prodrug of dextroamphetamine

Lisdextroamfetamine

19

Toxicity of Amphetamines (At much higher doses than used for ADHD)

Acute toxicity --> Psychosis --> Neurotoxicity --> Meth mouth --> Abuse Liability

20

Agonist of nicotinic cholinergic receptors

Nicotine

21

What are the two mechanisms of action of Nicotine?

NMJ: initially activates muscle contraction, but then desensitizes Autonomic ganglia: sympathetic --> release of epinephrine from adrenal; parasympathetic --> GI effects

22

Where are nicotinic receptors in the CNS?

Nucleus accumbens--> monovalent cation channels, activation leads to membrane depolarization and neuronal excitation

23

What are the pharmacological effects of Nicotine?

CNS stimulant, increases alertness, increases dopamine release in limbic reward centers, muscle relaxant, activates chemoreceptor zone--> nausea (1st exposure)

24

Withdrawal symptoms of Nicotine

Irritability, hostility, impatience, anxiety, depression, difficulty concentrating, increase appetite, weight gain

25

Partial agonist of Nicotinic receptors; reduces craving by activation nACh Receptor, will not desensitize like nicotine, also blocks effects of nicotine if the person smoked (partial antagonist)

Varenicline

26

Antidepressant; Reduces cravings and some of the nicotine withdrawal symptoms; SE: dry mouth, insomnia; moderately effective

Bupropion