Psychostimulants

Question 1

Effects of psychostimulants

Answer 1

• Mood elevation
• Locomotor stimulation – increase in activity
• Alertness / wakefulness / decreased fatigue
• Increased ability to concentrate – Levels that are too high may cause paradoxical fixation on one small detail and lose concentration on big picture.
• Decreased appetite

Question 2

General mechanism of psychostimulants

Answer 2

Inhibit uptake via monoamine transporters (NE, 5HT, and DA; not selective like SSRI’s), evoke monoamine release, or both

Question 3

Uses of psychostimulants

Answer 3

ADHD, narcolepsy, prevention of fatigue, and appetite suppression

Question 4

Most common population / age for ADHD

Answer 4

More common in males. Peaks around age 10-12.

Question 5

Amphetamine
Brand name
Effects
Use
Mechanism
What time of day is it taken?
What helps w/ excretion?
Adverse rxns
Precautions

Answer 5

• Adderall
• Increases physical and mental performance
• Use – 1st line for ADHD. Narcolepsy. Off-label for obesity.
• Mechanism – Inhibits NE, DA, and 5HT uptake transporters. Also evokes monoamine release.
• Taken in morning to avoid sleep disturbance later in the day.
• Acidic urine pH promotes excretion in urine
• Adverse rxns –
• CNS: insomnia, restlessness, anorexia
• CV: tachycardia, angina
• Overdose may produce anxiety, agitation, biting, delirium, hallucinations, paranoia, psychosis, tremor, diaphoresis, flushing or pallor, hyperthermia, labile blood pressure and heart rate (hypotension or hypertension), palpitations, tachypnea, mydriasis, blurred vision
• Precautions
• CNS: severe anxiety, tension, agitation, psychosis, anorexia nervosa
• CV: advanced arteriosclerosis, coronary artery disease, HTN, cardiac structural abnormalities
• MAOI’s
• Hyperthyroidism
• Glaucoma; amphetamine can ↑ IOP

Question 6

Methylphenidate
Brand name
Use
Mechanism
Pharmacokinetics of reinforcement
2 types of drug
Adverse rxns
Precautions

Answer 6

• Ritalin
• Use – Most common drug for ADHD. Also used for narcoepsy. Less motor stimulation than amphetamine.
• Mechanism – More central DA uptake blockade than catecholamine release activity. Reinforcement occurs at DAT occupancy greater than 60%. Depends on speed of DAT blockade and rate of DA accumulation.
• Immediate release form may cause a crash at midday. Controlled delivery avoids trough and less likely to interfere w/ sleep at night.
• Adverse rxns – frequent but mild. Same as amphetamine.
• CNS: insomnia, restlessness, anorexia
• CV: tachycardia, angina
• Overdose may produce anxiety, agitation, biting, delirium, hallucinations, paranoia, psychosis, tremor, diaphoresis, flushing or pallor, hyperthermia, labile blood pressure and heart rate (hypotension or hypertension), palpitations, tachypnea, mydriasis, blurred vision
• Precautions – same as amphetamine minus hyperthyroidism
• CNS: severe anxiety, tension, agitation, psychosis, anorexia nervosa
• CV: advanced arteriosclerosis, coronary artery disease, HTN, cardiac structural abnormalities
• MAOI’s
• Glaucoma; amphetamine can ↑ IOP

Question 7

Modafinil
Type of drug
Use
Mechanism
Adverse rxns
Precaution

Answer 7

• Nonamphetamine stimulant
• Use – Promote wakefulness for narcolepsy, shift-related sleep disorder, and OSA. May be useful for treating cocaine dependence. Not ADHD.
• Mechanism – Unclear
• Adverse rxns
• CNS: headache, restlessness, euphoria, and altered mood
• GI: nausea / diarrhea
• CV: increased HR and BP
• Precaution – Not approved for use in pediatric pxs

Question 8

Atomoxetine
Use
Mechanism
Adverse rxns
Precaution

Answer 8

• Use – 1st nonstimulant drug for ADHD.
• Mechanism – NE reuptake inhibitor (NRI).
• Adverse rxns – usually diminish after 1 month.
• CNS: fatigue, emotional lability, insomnia, headache, restlessness, decreased libido
• CV: chest pain, tachycardia, hypertension
• GI: upper GI pain, NV, anorexia, constipation
• UG: problems with ejaculation, urinary hesitation
• Precaution – black box warning for slight increase in risk of suicidal ideation