high efficacy stimulants - amphetamines Flashcards
what is amphetamine?
the parent compound of a family of synthetic psychostimulants that are structurally related to dopamine (DA).
what are the similar to amphetamine plant compounds ?
- cathinone
- ephedrine
what is true about amphetamines and methamphetamines in terms of formation?
they are synthetic (MADE IN LAB)
what are the different types of amphetamines?
- L-amphetamine (Benzedrine)
- D-amphetamine (Dexedrine)
a. More potent than L-amphetamine
Narcolepsy, ADHD (Adderall)- Adderall: 3:1 mixture of D-amphetamine to
L-amphetamine!
- Adderall: 3:1 mixture of D-amphetamine to
what type of drug is amphetamines and what is its accepted medical use
schedule 2
for…
- ADHD
- Narcolepsy (can’t stay awake)
what is the physical characteristics of methamphetamine?
commonly found as an odorless, white or off-white, bitter-tasting powder
also found in pills, capsules & larger crystals.
compare amphetamines to cocaine
- longer half life
a. cocaine = 30 min
b. amphetamines = 12 hours - longer drug actions
a. up to 30 minutes
b. 10 hours - pattern of drug use
a. cocaine = binges
b. amphetamines = use every few hours for
days
what is the route of administration of amphetamine and methamphetamine?
Amphetamine: oral, intranasal, injection (IV or SC)
Methamphetamine: orally, intranasal, IV injection, inhalation (smoked)
what is the absorption of amphetamine and methamphetamine?
- water soluble so well absorbed in blood
- GI tract absorption is slow
- amphetamines are weak bases
- high doses of vitamin C (ascorbic acid) can impair amphetamine absoption cuz it makes your GI more acidic and amphetamines are weak bases
- IV/smokes is very rapid
what is the disribution of amphetamine and methamphetamine?
- Highly lipophilic, readily crosses BBB
- ~20% of amphetamine gets trapped by plasma proteins (depot binding)
- Methamphetamine gets into the brain more quickly than d-amphetamine & l-amphetamine!
-D-amphetamine more potent than l-amphetamine
where are amphetamines and metamphetamines metabolized and what enzymes do the metabolism at those sites?
liver: CYP enzymes
brain: monoamine oxidases (MAO)
are amphetamines and metamphetamines completely broken down?
no
what is metamphetmaine metabolized into?
an active metabolite called amphetamine – so it re-enters your system and produces biological actions
what is amphetamine metabolized into?
an active metabolite 9k4-hydroxyamphetamine
what does the active metabolite of amphetamine cause?
4-hydroxyamphetamine dilates pupils, possibly causes hallucinations in animal models!
what is the half life of amphetamines and metamphetamines?
10-12 hours post administration , so much longer than cocaine
what is the rate of excretion influenced by?
pH of urine
acidic (low ph) urine – drug is removed more quickly
alkaline (high ph) urine – drug is removed less quickly
what is methamphetamine excreted as?
~50% excreted unchanged
~excreted as amphetamine!
what is amphetamine excreted as?
~40% excreted unchanged
what are the ways of excretion that we can detect levels of amphetamine?
- urine (MOST COMMON)
- blood
- saliva
- nails
- hair follicles
what neurotransmitter causes the objective effects of the drugs? what are these effects?
norepinephrine
- Blood pressure and heart rate increase
- Relaxation of the bronchioles
- Activation of fat breakdown
- Arousing effects
- Appetite effects
what happens when the drugs interact with our serotonin receptors?
- Body temperature increase
- Appetite effects
what neurotransmitter causes the subjective effects of the drugs? what are these effects?
dopamine
- Locomotor activation (tics)
- Euphoria
- Effects on attention
- Reinforcement
- Addiction
what are the behavioral symptoms that increase drug seeking behavior?
- heightened concentration
- increased self confidence
- reduced appetite
- increased alertness
