Chapter 13 Central Nervous System Stimulants and Related Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc

Chapter 13

Central Nervous System Stimulants and Related Drugs

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Drugs that stimulate a specific area of the brain or spinal cord

Sympathomimetic drugs

CNS Stimulants

2Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Classified according to: Chemical structural similarities

or Site of therapeutic action in the central nervous

system (CNS)

or Major therapeutic uses (attention deficit hyperactivity

disorder [ADHD], narcolepsy, obesity, migraine, and respiratory depression syndromes)

Classification


ADHD amphetamine (Dexedrine, Adderall) methylphenidate (Concerta, Ritalin, Metadate CD) atomoxetine (Strattera)

• Nonaddictive

• May cause suicidal thinking and behavior

lisdexamfetamine (Vyvanse)• Prodrug for dextroamphetamine

Drugs for ADHD and Narcolepsy


Drugs for ADHD and Narcolepsy (cont’d)

Narcolepsy modafinil (Provigil) armodafinil (Nuvigil)


Amphetamines Stimulate areas of the brain associated with mental

alertness CNS effects

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

Mechanism of Action and Drug Effects


Mechanism of Action and Drug Effects (cont’d)

Respiratory effects Relaxation of bronchial smooth muscle Increased respiration Dilation of pulmonary arteries


Wide range, dose-related Tend to “speed up” body systems Common adverse effects include:

Palpitations, tachycardia, hypertension, angina, dysrhythmias, nervousness, restlessness, anxiety, insomnia, nausea, vomiting, diarrhea, dry mouth, increased urinary frequency, others

Adverse Effects


Classroom Response Question

A teenaged boy will be receiving atomoxetine (Strattera) as part of treatment for attention deficit hyperactivity disorder (ADHD). Which statement about this drug therapy is accurate?

A. Strattera is highly addictive.

B. Psychotherapy is rarely helpful in cases of ADHD.

C. The patient should be monitored for possible suicidal thoughts and behavior.

D. Strattera is used to treat narcolepsy as well as ADHD.


Used to treat obesity Anorexiants

benzphetamine (Didrex) methamphetamine (Desoxyn) phentermine (Ionamin) orlistat (Xenical)

• Lipase inhibitor, not a CNS stimulant

• Also used to treat obesity

• May cause fecal incontinence

Anorexiants


Suppress appetite control centers in the brain Increase the body’s basal metabolic rate Mobilization of adipose tissue stores Enhanced cellular glucose uptake Reduce dietary fat absorption

Mechanism of Action



A patient wants to take orlistat (Xenical) to assist in her weight loss program, but she is wary of its unpleasant adverse effects. What measure can be suggested to reduce these effects?

A. Restrict dietary intake of fat

B. Restrict dietary intake of fiber

C. Increase intake of dairy products

D. Avoid intake of carbonated beverages


Adverse Effects

Possible elevated blood pressure and heart palpitations

Anxiety Agitation Dizziness Headache


Antimigraine (serotonin agonists; also called triptans) almotriptan (Axert) eletriptan (Relpax) frovatriptan (Frova) naratriptan (Amerge) rizatriptan (Maxalt) sumatriptan (Imitrex) zolmitriptan (Zomig)

Antimigraine Drugs


Ergot alkaloids ergotamine dihydroergotamine mesylate (D.H.E. 45) (Migranal) ergotamine tartrate with caffeine (Cafergot)

Antimigraine Drugs (cont’d)



Prior to administering a serotonin agonist, it is most important for the nurse to assess the patient for a history of

A. hypertension.

B. allergy to penicillin.

C. chronic bronchitis.

D. cataracts.


Mechanism of Action and Drug Effects

Triptans Stimulate 5-HT receptors in cerebral arteries, causing

vasoconstriction and reducing headache symptoms Reduce the production of inflammatory neuropeptides

Ergot alkaloids Narrow or constrict blood vessels in the brain


Triptans Vasocontstriction Irritation at injection site Tingling, flushing

Ergot alkaloids Nausea and vomiting Cold or clammy hands and feet Muscle pain Dizziness Others

Adverse Effects


Used less frequently Still used for neonatal apnea Examples:

doxapram (Dopram) Methylxanthines, such as aminophylline, theophylline,

and caffeine

Analeptics


doxapram (Dopram) Treatment of respiratory depression associated with

anesthetic drugs and drugs of abuse, COPD-induced hypercapnia

Monitor deep tendon reflexes, in addition to vital signs and heart rhythm, to prevent overdosage of this drug

Analeptics (cont’d)


Caffeine Found in:

• Over-the-counter drugs

• Combination prescription drugs

• Foods and beverages

Use with caution in patients with a history of:• Peptic ulcer

• Recent myocardial infarction

• Dysrhythmias

Analeptics (cont’d)


Mechanism of Action

Stimulate areas of CNS that control respiration Methylxanthines

Inhibit phoshodiesterase, leading to buildup of cyclic adenosine monophosphate (cAMP)

Caffeine Antagonizes adenosine receptors


Adverse Effects

Vagal Stimulation of gastric secretions, diarrhea, and reflex

tachycardia Vasomotor

Flushing, sweating Respiratory

Elevated respiratory rate Musculoskeletal

Muscular tension and tremors


Assess for: Potential contraindications Potential interactions, including herbal therapies Conditions such as abnormal cardiac rhythms,

seizures, palpitations, liver problems For children, assess baseline height and weight

Nursing Implications


Drugs for ADHD 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 Drug “holidays” may be ordered Instruct parents to keep a journal to monitor child’s response to

therapy Monitor child for continued physical growth, including height and

weight

Nursing Implications (cont’d)



A patient is prescribed an anorexiant. Which statement will the nurse include in patient teaching?

A. “Take the medication with your evening meal.”

B. “You will need to take this drug for at least 2 years.”

C. “If you develop a dry mouth, stop taking the drug immediately.”

D. “Avoid intake of caffeine.”


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



SSRAs 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




Ergot alkaloids Chest pain, confusion, slurred speech, vision changes

need immediate medical attention Analeptics

Pay close attention to ABCs because of patient’s diminished sensorium


Monitor for therapeutic responses 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 Monitor for adverse effects



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Chapter 13 Central Nervous System Stimulants and Related Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc