Central Nervous System Stimulants and Related Drugs Flashcards
Central Nervous System Stimulants
- 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
Classification
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
Attention-deficit hyperactivity disorder
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
Attention-Deficit Hyperactivity Disorder symptoms?
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.
Narcolepsy
- 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.
Obesity
- 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
Migraine
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
Drugs for ADHD and Narcolepsy
- Amphetamines: methylphenidate (Ritalin)
- Nonamphetamine stimulant
(Modafinil) - Nonstimulant drugs
(atomoxetine; also used to treat ADHD)
lisdexamfetamine (Vyvanse®): prodrug for dextroamphetamine
Mechanism of Action and Drug Effects - Amphetamines
Stimulate areas of the brain associated with mental alertness
Mechanism of Action and Drug Effects - 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 - Respiratory effects
- Relaxation of bronchial smooth muscle
- Increased respiration
- Dilation of pulmonary arteries
Common Adverse Effects
Common adverse effects include:
- Palpitations, tachycardia, hypertension, angina, anxiety, insomnia, headache, tremor, nausea, vomiting, diarrhea, dry mouth, increased metabolic rate, others
Common Adverse Effects
- Wide range; dose related
- Tend to “speed up” body systems
Principal Drugs Used to Treat ADHD and Narcolepsy
Atomoxetine: nonstimulant drug also used for ADHD
Amphetamines
amphetamine aspartate (Adderall®): one of the most commonly prescribed drugs for ADHD
atomoxetine hydrochloride (Strattera®)
- 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.
methylphenidate hydrochloride (Ritalin®) does what?
First prescription drug indicated for ADHD
Also used for narcolepsy
modafinil (Alertec®)
- 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
what does Anorexiants
- 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
Adverse Effects of Orlistat
- Headache
- Upper respiratory infection
- Gastrointestinal (GI) distress, fecal incontinence
Antimigraine Drugs
Antimigraine (serotonin agonists; also called triptans)
- sumatriptan (Imitrex®)
Antimigraine Drugs - Ergot alkaloids
- 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
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
Mechanism of Action and Drug Effects - Ergot alkaloids
Constrict or narrow blood vessels in the brain
Adverse Effects of Triptansand Ergot Alkaloids
Triptans
Vasoconstriction
Irritation at injection site
Tingling, flushing, congestion
Analeptics
Used less frequently
Still used for neonatal apnea
examples of analeptics
caffeine
Analeptics - caffeine
Caffeine
Found in:
Over-the-counter drugs
Combination prescription drugs: Fiorinal-C 1/2®
Foods and beverages
Mechanism of Action - 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
Nursing Implications
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
Drugs for ADHD
- adverse effects
- 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.
Nursing Implications - Anorexiants
- Follow instructions for diet and exercise.
- Take in the morning.
- Avoid caffeine.
- Fat-soluble vitamin supplementation may be needed.
Nursing Implications - Selective serotonin receptor agonists
- 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.
Nursing Implications - Ergot alkaloids
Chest pain, confusion, slurred speech, and vision changes need immediate medical attention
Nursing Implications - Analeptics
Pay close attention to airway, breathing, and circulation because of the patient’s diminished sensorium.
Nursing Implications - 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
