Central Nervous System Stimulants and Related Drugs

Question 1

Central Nervous System Stimulants

Answer 1

• Drugs that stimulate a specific area of the brain or spinal cord
• Neurons contain receptors for excitatory neurotransmitters, including dopamine (dopaminergic drugs), norepinephrine (adrenergic drugs), and serotonin (serotonergic drugs).
• Sympathomimetic drugs

Question 2

Classification

Answer 2

Classification according to:
- chemical structural similarities: amphetamines, serotonin agonists, sympathomimetics, and xanthines.
- site of therapeutic action in the CNS
- Major therapeutic uses: anti-attention-deficit/hyperactivity disorder, anti-narcoleptic, anorexiant, anti-migraine, analeptic drugs

Question 3

Attention-deficit hyperactivity disorder

Answer 3

Most common neurodevelopmental disorder in children, affecting 3 to 10% of school-age children
Boys affected two to nine times more often than girls are
- May be related to the underdiagnosing in girls

Question 4

Attention-Deficit Hyperactivity Disorder symptoms?

Answer 4

Primary symptom of attention-deficit/hyperactivity disorder (ADHD): inappropriate ability to maintain attention span, or hyperactivity and impulsivity. Drug therapy for both childhood and adult ADHD is the same.

Question 5

Narcolepsy

Answer 5

• Incurable neurological condition in which patients unexpectedly fall asleep in the middle of normal daily activities.
• Cataplexy: sudden acute skeletal muscle weakness
  —- Triggered by strong emotion
• Commonly knees buckle, and the individual falls to the floor while still awake.

Question 6

Obesity

Answer 6

• Approximately 7 million obese adults and
  600 000 obese school-aged children in Canada
• Associated health risks
• Expected to rise 4 to 5 % per year

Question 7

Migraine

Answer 7

Common type of recurring headache, usually lasting from 4 to 72 hours
Typical features: pulsatile quality with pain that worsens with each pulse
Most commonly unilateral but may occur on both sides of the head
Associated symptoms: nausea, vomiting, photophobia (patient avoids light), phonophobia (patient avoids sounds)
Aura

Question 8

Drugs for ADHD and Narcolepsy

Answer 8

• Amphetamines: methylphenidate (Ritalin)
• Nonamphetamine stimulant
  (Modafinil)
• Nonstimulant drugs
  (atomoxetine; also used to treat ADHD)
  lisdexamfetamine (Vyvanse®): prodrug for dextroamphetamine

Question 9

Mechanism of Action and Drug Effects - Amphetamines

Answer 9

Stimulate areas of the brain associated with mental alertness

Question 10

Mechanism of Action and Drug Effects - CNS effects

Answer 10

• Mood elevation or euphoria
• Increased mental alertness and capacity for work
• Decreased fatigue and drowsiness
• Prolonged wakefulness

Question 11

Mechanism of Action and Drug Effects - Respiratory effects

Answer 11

• Relaxation of bronchial smooth muscle
• Increased respiration
• Dilation of pulmonary arteries

Question 12

Common Adverse Effects

Answer 12

Common adverse effects include:
- Palpitations, tachycardia, hypertension, angina, anxiety, insomnia, headache, tremor, nausea, vomiting, diarrhea, dry mouth, increased metabolic rate, others

Question 13

Common Adverse Effects

Answer 13

• Wide range; dose related
• Tend to “speed up” body systems

Question 14

Principal Drugs Used to Treat ADHD and Narcolepsy

Answer 14

Atomoxetine: nonstimulant drug also used for ADHD

Question 15

Amphetamines

Answer 15

amphetamine aspartate (Adderall®): one of the most commonly prescribed drugs for ADHD

Question 16

atomoxetine hydrochloride (Strattera®)

Answer 16

• Approved for treating ADHD in children older than 6 years of age and in adults
• Health Canada has issued a warning describing cases of suicidal thinking and behaviour in small numbers of adolescent patients receiving this medication.

Question 17

methylphenidate hydrochloride (Ritalin®) does what?

Answer 17

First prescription drug indicated for ADHD
Also used for narcolepsy

Question 18

modafinil (Alertec®)

Answer 18

• Use: improvement of wakefulness in patients with excessive daytime sleepiness associated with narcolepsy and with “shift work” sleep disorder
• Less potential for misuse than amphetamines and methylphenidate
• Available with a prescription

Question 18

what does Anorexiants

Answer 18

• Used to treat obesity
• Effectiveness has not been proven
• None currently available in Canada to treat obesity
• Related drug, orlistat (Xenical®), a nonstimulant drug to treat obesity

Question 19

Adverse Effects of Orlistat

Answer 19

• Headache
• Upper respiratory infection
• Gastrointestinal (GI) distress, fecal incontinence

Question 20

Antimigraine Drugs

Answer 20

Antimigraine (serotonin agonists; also called triptans)
- sumatriptan (Imitrex®)

Question 21

Antimigraine Drugs - Ergot alkaloids

Answer 21

• Were the mainstay of treatment of migraine headaches but have been replaced by the triptans for first-line therapy
• Obtained from a fungus and cause vasoconstriction of blood vessels in the brain and carotid arteries

Question 22

Mechanism of Action and Drug Effects - Triptans

Answer 22

Stimulate 5-HT receptors in cerebral arteries, causing vasoconstriction and reducing headache symptoms
Reduce the production of inflammatory neuropeptides

Question 23

Mechanism of Action and Drug Effects - Ergot alkaloids

Answer 23

Constrict or narrow blood vessels in the brain

Question 24

Adverse Effects of Triptansand Ergot Alkaloids

Answer 24

Triptans Vasoconstriction Irritation at injection site Tingling, flushing, congestion

Question 25

Analeptics

Answer 25

Used less frequently Still used for neonatal apnea

Question 26

examples of analeptics

Answer 26

caffeine

Question 27

Analeptics - caffeine

Answer 27

Caffeine Found in: Over-the-counter drugs Combination prescription drugs: Fiorinal-C 1/2® Foods and beverages

Question 28

Mechanism of Action - caffeine

Answer 28

- antagonizes adenosine receptors

Question 29

Adverse Effects

Answer 29

Vagal Stimulation of gastric secretions, diarrhea, and reflex tachycardia Vasomotor Flushing, sweating Respiratory Elevated respiratory rate Musculoskeletal Muscular tension and tremors

Question 30

Nursing Implications

Answer 30

Assess for Potential contraindications Potential interactions, including with herbal therapies Conditions such as abnormal cardiac rhythms, seizures, palpitations, liver problems For children, baseline height and weight

Question 31

Drugs for ADHD - adverse effects

Answer 31

- Last daily dose should be given 4 to 6 hours before bedtime to reduce insomnia. - Take on an empty stomach 30 to 45 minutes before meals. - Medication-free times may be ordered. - Instruct parents to keep a journal to - Monitor the child’s response to therapy. Monitor the child for continued physical growth, including height and weight.

Question 32

Nursing Implications - Anorexiants

Answer 32

- Follow instructions for diet and exercise. - Take in the morning. - Avoid caffeine. - Fat-soluble vitamin supplementation may be needed.

Question 33

Nursing Implications - Selective serotonin receptor agonists

Answer 33

- Dissolvable wafers, nasal spray, and self-injectable forms - Provide specific teaching about correct administration. - Instruct patients to keep a journal to monitor response to therapy.

Question 34

Nursing Implications - Ergot alkaloids

Answer 34

Chest pain, confusion, slurred speech, and vision changes need immediate medical attention

Question 35

Nursing Implications - Analeptics

Answer 35

Pay close attention to airway, breathing, and circulation because of the patient’s diminished sensorium.

Question 36

Nursing Implications - Monitor for therapeutic responses.

Answer 36

ADHD: decreased hyperactivity, increased attention span and concentration Anorexiant: appetite control and weight loss Narcolepsy: decrease in sleepiness Serotonin agonist: decrease in frequency, duration, and severity of migraines