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Questions and Answers
Which contraindication is NOT associated with the use of anorexiants?
Which contraindication is NOT associated with the use of anorexiants?
Anorexiants should be taken in the evening to avoid insomnia.
Anorexiants should be taken in the evening to avoid insomnia.
False
What dietary fat intake percentage should be restricted to reduce gastrointestinal adverse effects while using obesity treatments?
What dietary fat intake percentage should be restricted to reduce gastrointestinal adverse effects while using obesity treatments?
Less than 30%
Orlistat can lead to ______ incontinence as a side effect.
Orlistat can lead to ______ incontinence as a side effect.
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Match the adverse effects of anorexiants with their descriptions:
Match the adverse effects of anorexiants with their descriptions:
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What is the primary function of levodopa in the brain?
What is the primary function of levodopa in the brain?
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Carbidopa can cross the blood-brain barrier.
Carbidopa can cross the blood-brain barrier.
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Name one potential adverse effect of levodopa therapy.
Name one potential adverse effect of levodopa therapy.
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Levodopa is often given in combination with __________ to enhance its effectiveness.
Levodopa is often given in combination with __________ to enhance its effectiveness.
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Match the following medications with their roles:
Match the following medications with their roles:
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What is the primary effect of anorexiants?
What is the primary effect of anorexiants?
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Serotonin agonists can increase the frequency and duration of migraines.
Serotonin agonists can increase the frequency and duration of migraines.
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What should you monitor in patients taking antiepileptic drugs?
What should you monitor in patients taking antiepileptic drugs?
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Anorexiants are used for __________ control.
Anorexiants are used for __________ control.
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Match the medical condition with its primary treatment:
Match the medical condition with its primary treatment:
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What is a nursing implication for the administration of oral antiepileptic drugs?
What is a nursing implication for the administration of oral antiepileptic drugs?
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It is safe to use any type of fluid with intravenous phenytoin (Dilantin).
It is safe to use any type of fluid with intravenous phenytoin (Dilantin).
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What is the mechanism of action of Levetiracetam?
What is the mechanism of action of Levetiracetam?
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Study Notes
Central Nervous System (CNS) Stimulants and Related Drugs
- The CNS is a complex system in the human body
- CNS activity is regulated by a "checks-and-balances system"
- Excessive stimulation of excitatory neurons or blockade of inhibitory neurons can occur
- Receptors in the CNS are affected
- CNS stimulant drugs stimulate excitatory neurons in the brain
- Neurons contain receptors for excitatory neurotransmitters
- Dopamine, norepinephrine, and serotonin are excitatory neurotransmitters
- Drugs that affect these neurotransmitters are involved in treatment
- Drugs are classified by chemical structural similarities (amphetamines, serotonin agonists, sympathomimetics, xanthines)
- Drugs are also categorized by their site of therapeutic action in the CNS
- Major therapeutic uses include those for attention deficit disorder, antinarcoleptic, anorexiant, antimigraine, and analeptic drugs
Attention Deficit Hyperactivity Disorder (ADHD)
- ADHD is the most common psychiatric disorder in children
- Affecting 4% to 10% of school-age children, approximately 6% are treated with medication
- Boys are affected more often than girls (there are differences in presentation in girls)
- Primary symptoms include inappropriate ability to maintain attention span and presence of hyperactivity and impulsivity
Narcolepsy
- Narcolepsy is an incurable neurologic condition
- Patients unexpectedly fall asleep in the middle of normal daily activities
- These "sleep attacks" are reported to cause car accidents in 70% or more of patients
Drugs for ADHD and Narcolepsy
- CNS stimulants are first-line drugs for both ADHD and Narcolepsy
- Amphetamines, such as methylphenidate, are common
- Atomoxetine is a nonstimulant drug also used to treat ADHD
Mechanism of Action and Drug Effects (Amphetamines)
- Amphetamines increase the effects of norepinephrine and dopamine in the CNS synapses
- This is accomplished by increasing release and blocking reuptake
- Noriepi & Dop are in contact with their receptors longer, extending the duration of action
- Stimulates areas of the brain associated with mental alertness
- Effects include mood elevation, euphoria, increased mental alertness, decreased fatigue, and prolonged wakefulness
- Respiratory effects include relaxation of bronchial smooth muscle, increased respiration, and dilation of pulmonary arteries.
Indications/Contraindications
- Indications: ADHD, narcolepsy, obesity
- Contraindications: known drug allergy, cardiac structural abnormalities, recent MAOI usage
Adverse Effects
- Wide range of adverse effects are dose-related
- Tend to "speed up" bodily systems
- Common effects include palpitations, tachycardia, hypertension, angina, dysrhythmias, nervousness, restlessness, anxiety, insomnia, nausea, vomiting, diarrhea, dry mouth, and increased urinary frequency
Principal Drugs Used to Treat ADHD and Narcolepsy (Examples)
- Amphetamines: methylphenidate
- Amphetamine sulfate (Adderall): Commonly prescribed for ADHD
- Nonamphetamine stimulants: atomoxetine (nonstimulant drug also used for ADHD)
Atomoxetine (Strattera)
- Approved for ADHD in children over 6 and adults
- Not a controlled substance
- Lacks addictive properties
- FDA warning (September 2005): suicidal thinking and behavior in some adolescent patients
Methylphenidate (Ritalin)
- First prescription drug indicated for ADHD
- Also used for narcolepsy
- Extended-release dosage forms (e.g., Ritalin SR, Concerta, Metadate CD)
Nursing Implications (ADHD, Narcolepsy, similar conditions)
- Last dose should be given 4-6 hours before bed to reduce insomnia
- Take on an empty stomach 30-45 minutes before meals
- Monitor for continued physical growth (height/weight)
- Instruct patients/parents to keep a journal to monitor the child's response
Obesity
- 35% of Americans are obese and nearly two-thirds are overweight
- More than 78 million obese adults
Anorexiants
- Any substance that suppresses appetite
- Used to treat obesity
- Benzphetamine (Regimex) and Methamphetamine (Desoxyn) are examples
- Only approved for treatment of obesity
Mechanism of Action (Anorexiants)
- Suppress appetite control centers in the brain
- Increase the body's basal metabolic rate
- Mobilize adipose tissue stores
- Enhance cellular glucose uptake
- Reduce dietary fat absorption
Other Drugs to Treat Obesity (Examples)
- Orlistat (Xenical)
Indications/Contraindications (Anorexiants)
- Used to treat obesity in conjunction with diet and exercise, specifically higher risk patients
- Contraindications: drug allergy, severe cardiovascular disease, uncontrolled HTN, hyperthyroidism, eating disorders, MAOI usage
Adverse Effects (Anorexiants)
- Possible elevated blood pressure and heart palpitations, anxiety, agitation, dizziness, headache
- Orlistat: Oily spotting, flatulence, fecal incontinence.
Nursing Implications (Anorexiants)
- Follow instructions for diet and exercise plans (start small)
- Take in the morning. Avoid caffeine.
- Monitor for fat-soluble vitamin supplementation needs
Migraine
- Common type of recurring headache, lasting 4 to 72 hours (3 hrs)
- Typical features include: pulsatile quality with pain worsening with each pulse
- Most commonly unilateral but can occur on both sides of the head
- Associated symptoms such as nausea, vomiting, photophobia (avoidance of light), and phonophobia (avoidance of sound)
- Aura can occur
Migraine Symptoms (Potential)
- Headache, dizziness, nausea, vomiting, frequent yawning, neck stiffness, moodiness, constipation, blurred vision, lack of sleep, sensitivity to weather, sound, smell, and light; thirst
Antimigraine Drugs (Examples)
- Anti-migraine drugs (serotonin agonists or triptans): sumatriptan (Imitrex), almotriptan (Axert)
Mechanism of Action (Triptans)
- Stimulate 5-HT receptors in cerebral arteries causing vasoconstriction
- Reduce inflammatory neuropeptides
Adverse Effects (Triptans)
- Vasoconstriction, irritation at injection site, tingling, flushing
Serotonin Receptor Agonists (Sumatriptan (Imitrex))
- Original prototype drug in this class, seven triptans
- Effects are comparable overall
- Relief from moderate to severe migraines within 2 hours
- Stimulate 5-HT1 receptors; causes vasoconstriction
- Reduces production of inflammatory neuropeptides
- Available in various forms (oral, sublingual tablets, SC injection, and nasal sprays)
Nursing Implications (Triptans)
- Provide specific instruction about correct administration
- Instruct patients to keep a journal to monitor response to therapy
Monitor (Different Conditions: General)
- Monitor for response to drug therapy
- Monitor for adverse effects
- Include focus, grades, attention span, appetite control, weight loss, sleepiness, seizure frequency, severity & duration, etc...
Antiepileptic Drugs (AEDs) (Anticonvulsants)
- Control or prevent seizures for optimal quality of life
- Minimize AED-induced adverse effects & toxicity
- Therapy is usually lifelong, seizure free for 1-2 years for a period of time
- Combination of drugs may be used
Mechanism of Action (AEDs)
- Exact mechanism unknown, less excitable cell membranes, reduces nerve ability to be stimulated, suppresses neural impulse transmission, decreases nerve conduction speed
Indications (AEDs)
- Prevention/control of seizure activity, long-term maintenance therapy for chronic/recurring seizures, acute treatment of convulsions/status epilepticus, other uses
Adverse Effects (AEDs)
- Numerous adverse effects (varying by drug) (often necessitates a change in medication), black box warning (2008): suicidal thoughts and behaviors. Long-term therapy with phenytoin (Dilantin): gingival hyperplasia, acne, hirsutism, and Dilantin facies.
Interactions (AEDs)
- Numerous drug interactions (many antiepileptic drugs interact with each other), induce hepatic metabolism, reduction of other drug effects, and interfere with birth control
- Avoid grapefruit with carbamazepine
Antiepileptic Drug Listing (Examples)
- Valproic acid
- Gabapentin (Neurontin)
- Lamotrigine (Lamictal)
- Levetiracetam (Keppra)
- Topiramate (Topamax)
- Pregabalin (Lyrica)
Hydantoins: Phenytoin (Dilantin)
- First-line drug for many years
- Adverse effects: gingival hyperplasia, acne, hirsutism, Dilantin facies, osteoporosis
- Therapeutic drug levels: 10-20 µg/mL
- Highly protein bound
Hydantoins: Fosphenytoin (Cerebyx)
- Injectable prodrug of phenytoin
- Water-soluble phenytoin derivative
- Intramuscular or intravenous administration without burning on injection
- Adverse effects
Levetiracetam (Keppra)
- Adjunct therapy for partial seizures
- Contraindication: known drug allergy
- Mechanism of action: unknown
- Generally well tolerated
- No significant drug interactions
Safety (Look-alike/Sound-alike Drugs)
- Be careful with drug names
- Use both trade and generic names
Parkinson's Disease (PD)
- Chronic, progressive, degenerative disorder
- Affects dopamine-producing neurons in the brain
- Caused by an imbalance of dopamine and acetylcholine
- Symptoms appear when approximately 80% of the dopamine stored in the substantia nigra is depleted
- Includes progressive conditions, rapid swings (on-off phenomenon) when too little dopamine is present, dyskinesia when too much dopamine is present, and others (i.e.; dementia)
Parkinson's Disease Symptoms (Examples)
- Stooped posture, masked face, back rigidity, flexed elbows and wrists, forward tilt of trunk, reduced arm swing, tremors in legs, hand tremor, slightly flexed hips/knees, shuffling gait, short steps
Dyskinesia
- Difficulty in performing voluntary movements
- Two common types: chorea (irregular, spasmodic, involuntary movements), dystonia (abnormal muscle tone)
Treatment of Parkinson's Disease (General)
- Full explanation of disease to patients
- Treatment centers on drug therapy for Parkinson's Disease
- PT, OT, speech therapy important for patients with Parkinson's Disease
- Severe cases might require deep brain stimulation.
Pharmacology Overview (PD)
- PD is thought to be caused by an imbalance of dopamine and acetylcholine, primarily a deficiency of dopamine in certain brain areas.
- Drug therapies aim to increase dopamine levels or antagonize acetylcholine's effects
- Unfortunately, current drug therapy does not slow the progression of the disease, but slows progression of symptoms.
Indirect-Acting Dopaminergic Drugs: Monoamine Oxidase Inhibitors (MAOIs)
- MAOIs break down catecholamines in the brain
- Selegiline (Eldepryl) and rasagiline (Azilect) are selective MAO-B inhibitors.
- Cause an increase in levels of dopaminergic stimulation in the brain
- Do not elicit the "cheese effect" of nonselective MAOIs
Dopamine Modulator: Amantadine (Symmetrel)
- Causes release of dopamine from storage sites in presynaptic nerve cells.
- Blocks reuptake of dopamine
- Higher levels of dopamine in the synapses between nerves, improving dopamine neurotransmission
- Used early in treatment; effective possibly for 6-12 months
- Often used for dyskinesia associated with levodopa therapy
- Mild side effects (dizziness, insomnia, nausea)
- Increased anticholinergic adverse effects if taken with anticholinergic drugs
Dopamine Replacement Drugs (e.g., Levodopa, Carbidopa/Levodopa)
- Levodopa: biological precursor of dopamine required by the brain for dopamine synthesis; crosses the blood-brain barrier and is converted to dopamine
- Carbidopa: given with levodopa, does not cross the blood-brain barrier, prevents levodopa breakdown in periphery
- Consequently: more levodopa crosses the blood-brain barrier and converts to dopamine
Levodopa Therapy
- Levodopa is taken up by dopaminergic terminals, converted into dopamine, and released
- Controlled nerve terminal impairment enables effective neurotransmitter balance
- Eventually, levodopa loses control (5 to 10 years post-initiation)
- Contraindicated in those with angle-closure glaucoma requires caution in open-angle glaucoma
- Potential adverse effects: cardiac dysrhythmias, hypotension, chorea, muscle cramps, GI distress
Carbidopa-Levodopa (Sinemet)
- Sinemet CR increases "on" time, reduces "off" time
- Best taken with food to minimize GI upset
Anticholinergic Therapy
- Anticholinergics block acetylcholine (ACh) effects
- Used to treat muscle tremors and rigidity in PD (symptoms relating to excessive cholinergic activity)
- Does not relieve bradykinesia (extremely slow movement)
Anticholinergic Therapy (Cont.)
- SLUDGE: increased salivation, lacrimation (eye tearing), urination, diarrhea, increased GI motility, and possible emesis
- Anticholinergics have the opposite effect: dry mouth, decreased salivation, urinary retention, decreased GI motility (constipation), dilated pupils, and smooth muscle relaxation
Anticholinergics and Other Drugs Used for Treatment of PD (Examples)
- Benztropine (Cogentin): anticholinergic drug for PD and extrapyramidal symptoms in antipsychotic therapy; Caution w/ hot weather/exercise (hyperthermia)
- Adverse effects: tachycardia, confusion, disorientation, toxic psychosis, etc...
- Avoid alcohol.
Nursing Implications (PD Medications - General)
- Thorough assessment: nursing history, medication history, CNS, GI and GU tracts
- Assess for signs and symptoms of PD (mask-like expressions, speech problems, etc...)
- Assess for conditions that may be contraindications to meds
- Administer drugs carefully as directed by the manufacturer
- Teach/educate patient about PD, meds, therapy and expected effects
Nursing Implications (PD Medications - Cont.)
- Inform patient not to take other medications with PD meds unless checked with physician.
- Assist patient with ambulation when starting dopaminergic medications due to possible dizziness
- Administer meds with food for GI upset.
- Encourage patient to increase daily fluid intake to 3000 mL/day unless contraindicated.
- Avoid taking levodopa with MAOIs; risk of hypertensive crisis.
Nursing Implications (PD Medications - Cont II)
- Monitor for response to therapy; improved well-being/mental status, appetite increase, ability to perform ADLs, concentration and think.
- Monitor for adverse effects: parkinsonian manifestations, tremors, shuffling gait, muscle rigidity, involuntary movements
- Discuss the need to continue medication lifelong unless condition is reversed.
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Description
Test your knowledge on the use of anorexiants and levodopa in pharmacology. This quiz covers contraindications, dietary recommendations, adverse effects, and the primary functions of these medications. Ideal for students studying pharmacology or nursing.
