ADHD Pharm Flashcards
Neurobiology of ADHD
- Imbalance of catecholamine (NE & DA) metabolism in the cerebral cortex
- MOA of stimulants –> blocks the re-uptake of NE & DA into presynaptic neurons, causing the release of catecholamines from storage sites at the CNS synapses; appears to stimulate the cerebral cortex & subcortical structures (speeds up the part of the brain that slows you down)
Psychotropic meds in Peds vs Adults
- differ in response to meds
- children metabolize meds more rapidly (final maintenance dosages may be higher in children than in adults)
- adults often lack hyperactivity symptoms possibly making med selection different
ADHD Specific pharm treatments
In order to effectiveness of symptom control:
- CNS stimulants (methylphenidate); covers all of the symptoms
- Strattera (atomoxetine)
- Alpha agonists (guanfacine)
- Antidepressants (TCAs, bupropion)
CNS Stimulants
Actions --> increases vigilance, attention & short-term memory; decreases motor activity, impulsiveness, emotional lability Two groups --> Methylphenidate & Amphetamine Treatment --> start with a stimulant, if it doesn't work, switch to the other class of stimulants
Methylphenidate HCl
CNS stimulant schedule 2; NDRI
Action –> may improve impulse transmission by releasing stored NE & DA and prohibiting re-uptake (possibly in the cortex or reticular activating system)
Pharm –> should be given with food to ensure proper absorption
Immediate Release Methylphenidate
- begins working within 30 minutes (rapid onset), and lasts for 3-6 hours)
- BID or TID usually required
Methylphenidate Adverse Effects
- growth suppression due to appetite suppression
- delayed sleep
- headaches, stomach aches, irritability, aggression
- anxiety/nervousness
- skin picking
- may unmask or exacerbate tic disorders (contraindicated in people with tourette’s)
- seizures (can lower the seizure threshold)
- arrhythmias, chest pain, HTN, sudden death (contraindicated in people with cardiac structural issues)
- potential for psychosis (DA excess)
Amphetimine
NDRA
- ER: should be taken every morning (contained immediate and delayed release components)
- Common side effects: loss of appetite, insomnia, weight loss, emotional lability, depression
- temporarily removed from Canadian market due to sudden death due to interactions with structural cardiac problems & existing conditions
Black box warning on stimulants
- warning for sudden death associated with cardiac structural abnormalities
- abuse & dependence
- reports of murmur, syncope, chest pain, HTN or arrhythmias
- family hx of heart disease
- psychotic or bipolar disorders
- patients with tics or tourette’s
CNS stimulant serious side effects
(less common)
- death
- adverse cardiac effects
- hallucinations (tactile & visual usually)
- seizures
- mania/hypomania
Non-stimulants
- not controlled substances
- can take longer for med to take effect & not as robust effect as stimulants
- often used as mono therapy or adjuncts to stimulants
- typically used when patient has inadequate response to stimulants, Tic/Tourette’s disorder, , patient or family hx of SUDs, or patient doesn’t want to use stimulants
Atomoxetine HCl
Selective NE re-uptake inhibitor; non-stimulant
Dosing –> dosed by weight; taken each day or BID
Side effects –> similar to TCAs but generally better tolerated; need to be given with food; increased risk for suicide in child/adolescents
Use –> focus & attentiveness (not great for hyperactivity)
Warning –> potential for severe liver injury (via induction of metabolic idiosyncrasy or autoimmune hepatitis)
Guanfacine ER
Selective alpha-2a agonist; non-stimulant
MOA –> unknown, but works on NE signals in the brain somehow
Use –> approved for children 6-17 for hyperactivity (not great for inattentive symptoms)
Common side effects –> sedation, dizziness, orthostatic hypotension, dry mouth, bradycardia irritability, sleep disturbance
Most serious side effects –> hypotension, bradycardia & syncope, sedation & somnolence
Interactions –> Valproic acid (increases depakote levels), antihypertensives, CNS depressants
Caution –> rebound HTN associated with missed doses
Monitoring –> BP, HR
TCAs
Additional med for ADHD
Use –> if stimulants aren’t effective/tolerated, coexisting anxiety or depressive disorder
-not as effective as stimulants in improving attention & concentration
Clonidine
Alpha2-adrenergic agonist
- Use –> insomnia, aggressive behaviors; decreases excessive hyperactivity - calming (doesn’t improve inattention symptoms)
- need to monitor BP
