Stimulants

Chapter 17: Stimulants

CNS Stimulants

• Medically Approved Uses:

  • Attention-deficit/hyperactivity disorder (ADHD)

  • Narcolepsy

  • Reversal of respiratory distress

• Categories of CNS Stimulants:

  • Amphetamines:

  • Mechanism: Act on cerebral cortex

  • Analeptics (e.g., caffeine):

  • Mechanism: Act on brainstem and medulla

  • Anorexiants:

  • Mechanism: Act on satiety center in hypothalamic and limbic areas

Attention-Deficit/Hyperactivity Disorder (ADHD)

• Pathophysiology:

  • Dysregulation of neurotransmitters:

  • Serotonin

  • Norepinephrine

  • Dopamine

• Epidemiology:

  • Usually identified in children before the age of 7 years

  • More prevalent in boys

• Characteristics:

  • Inattentiveness and inability to concentrate

  • Restlessness and hyperactivity

  • Impulsivity and inability to complete tasks

  • Poor coordination

  • Note: Intelligence is generally unaffected; however, possible learning disabilities may be identified.

Characteristics of Narcolepsy

• Definition:

  • Recurrent attacks of drowsiness and sleep during normal waking activities

  • Inability to control sleep

• Examples:

  • Falling asleep while:

  • Driving

  • Talking

  • Eating

  • Standing

• Additional Symptoms:

  • Sleep paralysis

Amphetamines

• Mechanism of Action:

  • Stimulate the release of norepinephrine and dopamine

  • Inhibit the reuptake of norepinephrine and dopamine

• Physiological Effects:

  • Tachycardia

  • Palpitations

  • Hypertension

  • Restlessness, irritability

  • Confusion and euphoria

  • Insomnia and blurred vision

  • Dysrhythmias and tremors

  • Anorexia, dry mouth, weight loss

  • Diarrhea and constipation

  • Erectile dysfunction

  • Excessive use may lead to psychosis

  • Advisory: Avoid over-the-counter products containing caffeine or pseudoephedrine.

Amphetamine-Like Drugs for ADHD

• Examples:

  • Amphetamine Sulfate (Adderall)

  • Dextroamphetamine Sulfate (Dexedrine)

  • Lisdexamfetamine Dimesylate (Vyvanse)

  • Methylphenidate (Ritalin/Daytrana)

  • Dexmethylphenidate (Focalin)

• Uses:

  • Increase attention span and cognitive performance (memory, reading)

  • Decrease impulsiveness, hyperactivity, and restlessness

Amphetamine-Like Drugs for Narcolepsy

• Examples:

  • Methylphenidate (Ritalin)

  • Modafinil (Provigil)

• Action:

  • Not fully understood

• Uses:

  • Both drugs enhance wakefulness in patients with sleep disorders

Methylphenidate (Ritalin)

• Mechanism:

  • Modulates serotonergic pathways by affecting changes in dopamine transport

• Uses:

  • Treats ADHD and narcolepsy; increases attention span

• Interactions:

  • Caffeine may increase effects.

  • Increases effects of: oral anticoagulants, barbiturates, anticonvulsants, tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs)

  • Decreases effects of antihypertensives

  • May alter insulin effects

  • Warning: Use of Ritalin and MAOIs may cause a hypertensive crisis.

Side Effects/Adverse Reactions of Methylphenidate

• Physiological Reactions:

  • Tachycardia, palpitations, hypertension, dysrhythmias

  • Restlessness, sleeplessness, tremors, irritability

  • Dizziness, headache, blurred vision

  • Euphoria and confusion

  • Anorexia, dry mouth, diarrhea, constipation, weight loss

  • Seizures, erectile dysfunction

  • Adverse effects include growth suppression and thrombocytopenia

Nursing Process: Methylphenidate

• Assessment:

  • Monitor vital signs for future comparison.

• Nursing Diagnoses:

  • Health behavior, risk-prone (impulsiveness, short attention span, distractibility) that interferes with peer relationships, learning, and discipline.

• Planning Goals:

  • Increase the patient’s attention span.

  • Assist the patient in behaving in a calm manner.

• Nursing Interventions:

  • Instruct patient to take medication before meals (preferably before breakfast or lunch).

  • Advise avoidance of caffeinated foods.

  • Report any irregular heartbeat.

  • Record height, weight, and growth in children.

  • Advise against alcohol and caffeine.

  • Recommend sugar-free gum to relieve dry mouth.

  • Caution against abrupt cessation; taper off to avoid withdrawal symptoms.

  • Counseling is also important.

  • Keep medication secure.

• Evaluation:

  • Ongoing assessment of effectiveness and side effects.

Anorexiants

• Mechanism:

  • Cause a stimulant effect on hypothalamic and limbic areas to suppress appetite.

• Precautions:

  • Should not be given to children under 12.

• Side Effects/Adverse Reactions:

  • Nervousness, irritability, insomnia

  • Tachycardia, hypertension

  • Palpitations, seizures

Analeptics

• Examples:

  • Caffeine, theophylline

• Uses:

  • Stimulate newborn respirations for conditions like neonatal apnea.

  • Doxapram: Used for postanesthesia respiratory depression.

• Common Side Effects:

  • Palpitations, tachycardia, dysrhythmias

  • Insomnia, nervousness, restlessness

  • Tremors, seizures

Practice Questions

• Question #1:
  What would indicate to the nurse that the child taking methylphenidate requires more education?

  • A. The child is seen drinking a cola product.

  • B. The child checks his weight twice a week.

  • C. The child takes the drug 45 minutes before a meal.

  • D. The child takes the drug before breakfast and lunch.

• Question #2:
  A child has been diagnosed with ADHD. Which drug does the nurse anticipate the health care provider will prescribe?

  • A. Zolmitriptan

  • B. Doxapram

  • C. Benzphetamine

  • D. Methylphenidate

• Question #3:
  Methylphenidate should not be taken by patients with a history of which condition?

  • A. Renal failure

  • B. Glaucoma

  • C. Hypothyroidism

  • D. Mental depression

• Question #4:
  When providing teaching to a group of parents regarding ADHD, which information will the nurse include?

  • A. Children with ADHD have low intelligence.

  • B. Children with ADHD have an infection in their spinal fluid.

  • C. EEG results are typically normal in children with ADHD.

  • D. Learning disabilities are often present in the child who has ADHD.