42: CNS Stimulants and ADHD Flashcards
psychoactive drugs that stimulate the activity of CNS and PNS and temporarily enhance mental or physical functions
psychostimulants “uppers”
majority of CNS stimulants are chemically similar to…
NE
stimulate the flight or fight system
“sympathomimetics”
what do CNS stimulants increase?
alertness and awakeness productivity and motivation arousal, locomotion, HR, BP euphoria nervousness and anxiety
what do CNS stimulants decrease?
requirements for sleep and food intake
respiratory stimulant used to counteract postanesthetic respiratory depression
doxapram
binds to carotid a. chemoreceptors and medullary respiratory centers to increase tidal volume and respiratory rate
clinical use for caffeine
primary treatment for apnea of prematurity (breathing cessation in premature infants)
clinical use for theophylline
relaxes bronchial smooth muscle –> tx for COPD and asthma
MOA atomoxetine
NE reuptake inhibitor
what is the metabolism of CNS stimulants? why is that clinically important?
-peripheral degradation by MAOa/b and liver degradation via p450s
** avoid MAOi and SSRI agents (increase levels of drugs)
MOA analeptic stimulants
depression of inhibitory neurotransmission
GABAa and glycine antagonist –> decreased chloride influx and hyperpolarization
MOA methylxanthines
inhibition of CNS suppressant
reduce adenosine activity by A1 receptor antagonism
MOA amphetamines
enhancement of excitatory transmission
increase pre-synaptic release of catecholamines from vesicles/ decreases reuptake
MOA cocaine
enhancement of excitatory transmission
- inhibition of monoamine uptake via blockade of DA and NE and 5HT transporters
clinical use methylphenidate
ADHD
narcolepsy treatment
modafinil
CNS stimulant used to treat obesity
amphetamine
used for appetitie-suppressing properties
clinical use orlistat
weight loss
lipase inhibitor - decreases fat absorption
GI side effects of steatorrhea, fecal incontinence, flatulence
can SSRIs be used for weight loss?
weight loss in first 6-12 mo, long term lead to weight gain :(
3 legal uses of amphetamine
narcolepsy
ADHD
short-term weight loss
what area of the brain is associated with reward and affected by cocaine?
VTA ventral tegmental area
home of DA neurons
MOA cocaine
inhibits DAT and increases synaptic DA
MOA amphetmaine
competitively inhibits DAT and increases synaptic DA
also interferes with VMAT to release DA cytoplasmically and synaptically
CNS side effects of psychomotor stimulants
euphoria/dysphoria insomnia irritability tremor headache loss of appetite
cardiovascular side effects of CNS stimulants
Mi
stroke
endocrine side effects of psychomotor stimulants
anorexia, severe weight loss
ADHD criteria for diagnosis
inattention and impulsivity/hyperactivity
six or more from a list present for 6 months for both categories
areas of brain most affected by ADHD
- dorsolateral prefrontal cortex
- dorsal anterior cingulate cortex
- caudate and putamen
dopamine deficit hypothesis of ADHD
dorsal lateral prefrontal cortex lacks DA
PFC projects to anterior cingulate cortex –> integration of inattentiveness and regulation of emotions
- supported by Da enhancing treatments
FDA approved ADHD treatment with no abuse potential
atomoxetine
MOA clonidine
alpha2 agonist
tx for ADHD - increases blood flow to prefrontal cortex
MOA modafinil
activates histamine neurons in TMN of hypothalamus (promotes attention and awakeness) – sleep disorders
common side effects in ADHD treatment with CNS stimulants
decreased appetite and weight loss
insomnia
