10. Pharmacology of CNS Stimulants

Question 1

What are the 2 categories of ADHD medications?

Answer 1

1. Stimulants (amphetamines)
2. Non-stimulants

Question 2

Types of amphetamines

Answer 2

1. Amphetamine (d & l) and dextroamphetamine (methamphetamine)
2. Lisdexamfetamine (pro-drug)
3. Methylphenidate (d & l) and dexmethylphenidate

Question 3

Types of non-stimulants

Answer 3

1. Atomoxetine
2. Guanfacine
3. Clonidine

Question 4

MOA of the stimulants used for ADHD?

Answer 4

1. Block presynaptic reuptake of catecholamines and DA.
2. Interfere with VMAT
3. ↑ in NT release —> NE => DA => 5-HT, each at ↑ dose

Question 5

Which isomers of AMP/MPH have more CNS activity?

Answer 5

D-isomers of AMP/MPH

Question 6

What is methylphenidate’s main activity (MOA)?

Answer 6

• Inhibition reuptake of DA and other NT pre-synaptic reuptake
• Does NOT stimulate release of NT’s

Question 7

What must you always assess for before prescribing stimulants for ADHD?

Answer 7

Structural cardiac abnormalities, to prevent sudden cardiac death, strokes and MI

Question 8

Other RARE SE of stimulants

Answer 8

1. Chemical Leukoderma (w/ Daytrana patch)
2. Priapism
3. Seizures

Question 9

Describe what the following abbreviations mean:

1. IR
2. ER/XR
3. LA
4. CD
5. ODT

Answer 9

1. Immediate release
2. Extended release
3. Long-acting
4. Controlled delivery
5. Oral disintegrating tablet (ODT)

Question 10

What cautions are there when using stimulants?

Answer 10

1. ↑ anxiety/agitation
2. Caution in pts with
   
   1. Ineffectively-treated bipolar (mania)/psychosis)
   2. CV disease and moderate-to-severe HTN
   3. Glaucoma
   4. Motor tics/Tourettes
   5. Poorly-controlled seizures
   6. Hx of drug abuse

Question 11

What is the onset of activity for stimulants in most patients?

Answer 11

24 hours

Question 12

How are stimulants administered?

Answer 12

Stimulants are controlled substances (1 month supply only, no refills, no samples); some states, like MO, allow 3 months of Rxs (future-dating)

Question 13

What is the duration of action of the IR [amphetamine-based stimulants]?

Answer 13

4 - 6 hours

Question 14

IR [Amphetamine Stimulants]

Answer 14

1. Adderall (Dextroamphetamine/AMP)
2. Zenzidi (Dextroamphetamine)
3. ProCentra (Dextroamphetamine Sulfate)
4. Evekeo (Amphetamine Sulfate)

Question 15

Which IR amphetamine stimulant comes in a liquid form?

Answer 15

ProCentra (Dextroamphetamine Sulfate)

Question 16

Which IR amphetamine stimulant comes in a capsule?

Answer 16

Evekeo (Amphetamine Sulfate)

Question 17

ER [Amphetamine Stimulants]

Answer 17

1. Adderall XR (Dextroamphetamine)
2. Dexedrine (Dextroamphetamine)
3. Dyanavel XR (Amphetamine)
4. Mydayis (Amphetamine/Mixed Salts)
5. Vyvanse (Lisdexamfetamine)

Question 18

What is the ONLY liquid ER [amphetamine], while all of the other ones are capsules?

Answer 18

Dyanaval XR (Amphetamine)

Question 19

Which XR amphetamine stimulant comes in a capsule and has the longest duration (16 hrs)?

Answer 19

Mydayis (Amphetamine/Mixed Salts)

Question 20

What is the XR-ODT (oral disentegrating tablet) used for ADHD?

Who is it given to?

Answer 20

• Adzenys XR- ODT (d,l- amphetamine)
  
  • 3:1 ratio of d-amphetamine:l-amphetamine.
  • 50% IR and 50% XR
  • Approved for: > 6YO without water q.d (once/day)

Question 21

3 IR Methylphenidates

Answer 21

1. Focalin (Dexmethylphenidate)
2. Methylin Oral Solution (Methylphenidate)
3. Ritalin (Methylphenidate)

Question 22

IR Methylphenidates in tablet

Answer 22

1. Focalin (Dexmethylphenidate)
2. Ritalin (Methylphenidate)

Question 23

IR Methylphenidates in liquid

Answer 23

1. Methylin oral solution (Methylphenidate)

Question 24

2 Sustained Release Methylphenidates

Answer 24

1. Ritalin-SR (Methylphenidates)
2. Desoxyn (Methamphetamine)

Both are tablets that last 4-8 hours.

Question 25

Which XR methylphenidate stimulant comes in a transdermal patch?

Answer 25

Daytrana (Methylphenidate Transdermal)

Question 26

Which XR methylphenidate stimulants comes in a liquid and has formulas that last 8, 10, and 12-hours?

Answer 26

Quillivant XR (Methylphenidate)

Question 27

Which ER/XR Methylphenidate comes in a chewable tablet?

Answer 27

QuilliChew (Methylphenidate HCl)

Question 28

Which 4 XR Methylphenidate stimulants come in a capsule; which has the longest duration of action?

Answer 28

1. Aptensio XR (Methylphenidate): 12 hours
2. Focalin XR (Dexmethyphenidate HCl)
3. Metadate (Methylphenidate HCl)
4. Ritalin LA (Methylphenidate HCl ER)

Question 29

What is the (MOA) of the non-stimulants used for ADHD: Atomoxetine, Guanfacine and Clonidine?

Answer 29

Enhance NT transmission by:

1. Atomoxetine: inhibits pre-synaptic reuptake of NE.
2. Guanefacine/Clonidine: α-2A-R AGO

Question 30

What is the onset of activity for the non-stimulants used for ADHD?

Answer 30

1 - 4+ weeks

Question 31

How are NON-stimulants administered and why?

Answer 31

• Non-scheduled refills and samples that can be given up to 1 year.
• Useful for patients intolerant/resistant to stimulants.

Question 32

Atomoxetine (Strattera)

1. Form
2. Duration of action
3. How to use
4. Warnings

Answer 32

1. Capsule that lasts 24 hours
2. Q.D for ppl > 6YO
3. Warnings:
   
   1. Do not open the capsule => ocular irritant
   2. Metabolized by CYP2D6 (poor metabolizers/inhibitors)

Question 33

Which non-stimulants are ANTI-HYPERTENSIVES approved for ADHD?

Form? Duration of action?

Answer 33

1. Kapvay ER (Clonidine)
2. Intuniv ER (Guanfacine)

​Both are tablets and last 12-24 hours.

Question 34

What are common for both Guanfacine and Clonidine?

Answer 34

1. Do not crush, chew or break tablets.
2. Approved for > 6YO
3. Take once/day (Q.D)
4. When DQ, downwardly titrate over 1+ week, depending on dose due to risk of rebound HTN.