Parkinson’s Disease and Dopaminergic Agents

1. Scenario: A 68-year-old male newly diagnosed with Parkinson’s disease is

started on carbidopa/levodopa. However, he reports significant nausea after
taking the medication. How can this be managed?
o Answer: Carbidopa/levodopa should be taken with food
to minimize nausea, or a lower dose of carbidopa can be
considered to reduce peripheral breakdown of levodopa.
Additionally, a dopamine antagonist like domperidone
may be prescribed for nausea.

2. Scenario: A 70-year-old female with Parkinson’s disease who has been on

levodopa for several years begins to experience involuntary movements
(dyskinesias). What adjustments in her treatment regimen can be made?
o Answer: The levodopa dose should be reduced, or the
frequency of doses adjusted. Adding amantadine may
help reduce dyskinesias, as it has antidyskinetic
properties. Consideration of other dopaminergic agents
like dopamine agonists or a COMT inhibitor may also
help.

3. Scenario: A 74-year-old male with Parkinson’s disease develops

hallucinations and confusion while on long-term carbidopa/levodopa therapy.
What changes should be made in his treatment plan?
o Answer: The dose of levodopa should be adjusted, and
a switch to a dopamine agonist like pramipexole may be
considered, as it may cause fewer cognitive side effects.
Alternatively, adding a medication like pimavanserin (an
atypical antipsychotic) can be considered to manage
psychosis without worsening motor symptoms.

4. Scenario: A 60-year-old patient with early-stage Parkinson’s disease wishes

to delay the onset of motor complications. What medication might be
preferred over levodopa?
o Answer: A dopamine agonist such as pramipexole or
ropinirole may be preferred to delay motor fluctuations
and dyskinesias that typically develop with long-term
levodopa use.

5. Scenario: A 78-year-old female with Parkinson’s disease experiences

"wearing off" between doses of levodopa. What adjunctive treatment could
help?
o Answer: Entacapone, a COMT inhibitor, can be added to
help prolong levodopa’s effects and reduce "wearing
off." Alternatively, the dose of levodopa could be
adjusted, or a longer-acting form of levodopa could be
considered.
Monoamine Oxidase Type B (MAO-B) Inhibitors

6. Scenario: A 72-year-old male with Parkinson’s disease is prescribed

rasagiline. What advantage does rasagiline offer over levodopa in terms of
motor control?
o Answer: Rasagiline provides neuroprotective benefits
by inhibiting MAO-B, thereby preserving dopamine levels
in the brain. It can improve motor symptoms and may
be used early to delay the need for levodopa, which is
associated with motor complications over time.

7. Scenario: A 68-year-old female patient reports insomnia after starting

selegiline for Parkinson’s disease. Why might selegiline cause this, and what
adjustments can be made?
o Answer: Selegiline inhibits both MAO-A and MAO-B at
higher doses, leading to increased levels of
norepinephrine and serotonin, which may cause
insomnia. Reducing the dose or switching to a different
MAO-B inhibitor like rasagiline may alleviate this side
effect.

8. Scenario: A patient with Parkinson’s disease asks if dietary restrictions are

necessary while on selegiline. What advice should you give?
o Answer: Patients taking selegiline should avoid foods
containing high levels of tyramine (e.g., aged cheeses,
cured meats, soy products), as the combination could
lead to a hypertensive crisis due to the interaction of
tyramine with the drug.

Catechol-O-Methyltransferase (COMT) Inhibitors

9. Scenario: A 75-year-old male with Parkinson’s disease experiences "wearing

off" and is started on entacapone. What effect will this medication have on
levodopa?
o Answer: Entacapone inhibits COMT, an enzyme that
breaks down levodopa in the peripheral tissues. This
increases the bioavailability and duration of action of
levodopa, helping to reduce "wearing off" effects.

10. Scenario: A 70-year-old female patient on tolcapone for Parkinson’s disease

develops signs of liver dysfunction. What should be done?

 Answer: Tolcapone has a risk of hepatotoxicity, so it should

be discontinued if liver function abnormalities occur.
Alternative COMT inhibitors such as entacapone, which has a
lower risk of liver toxicity, may be considered.
 11. Scenario: A patient on levodopa develops brownish-
orange urine after starting entacapone. Is this side effect of
concern?

 Answer: This is a harmless side effect of entacapone due to

its metabolites. The discoloration of urine does not require
discontinuation of the medication.

Dopamine Agonists

12. Scenario: A 68-year-old male with Parkinson’s disease

is started on pramipexole. How does this medication compare
to levodopa in terms of motor complications?

 Answer: Dopamine agonists like pramipexole have a lower

risk of motor complications such as dyskinesias and motor
fluctuations compared to levodopa, especially when used
early in the disease.

13. Scenario: A 50-year-old female patient on pramipexole

for Parkinson’s disease develops compulsive gambling and
hypersexuality. What is the cause, and how should it be
managed?

 Answer: Pramipexole can cause impulse control disorders due

to overstimulation of dopamine receptors. The dose should be
reduced, or the medication may be discontinued. A switch to
another class of dopaminergic agents, such as levodopa, may
be necessary.

14. Scenario: An elderly patient on ropinirole develops

confusion and hallucinations. What is the likely cause, and
what changes should be made?

 Answer: Dopamine agonists like ropinirole can cause

confusion and hallucinations in elderly patients. The dose
should be reduced, or the medication may be switched to a
different dopaminergic agent, like levodopa, which may be
better tolerated in this population.

Amantadine and Anticholinergics

15. Scenario: A Parkinson’s patient develops dyskinesias

while on levodopa therapy. How might adding amantadine
help?
  Answer: Amantadine helps reduce dyskinesias by increasing
dopamine release and inhibiting its reuptake in the brain. It
also has anticholinergic effects, which can further reduce
tremors.

16. Scenario: A 72-year-old patient with Parkinson’s

disease and cognitive impairment is started on
trihexyphenidyl for tremor. Why might this be problematic?

 Answer: Anticholinergic medications like trihexyphenidyl can

worsen cognitive impairment in elderly patients, leading to
confusion, memory loss, and delirium. They should be used
cautiously or avoided in patients with cognitive decline.

Parkinson’s Nonmotor Symptoms and Other Treatments

17. Scenario: A 68-year-old Parkinson’s patient develops

REM sleep behavior disorder. Which Parkinson’s medication
might exacerbate this condition?

 Answer: Dopamine agonists such as pramipexole and

ropinirole may exacerbate REM sleep behavior disorder, as
they can alter sleep architecture and increase motor activity
during sleep.

18. Scenario: An advanced Parkinson’s patient is

experiencing "off" episodes despite optimized oral therapy.
What emergency injectable could be used?

 Answer: Apomorphine, an injectable dopamine agonist, can

provide rapid relief during "off" episodes, offering a quick on-
set effect to restore motor function.

Atypical Antipsychotics in Parkinson’s

19. Scenario: A 70-year-old male with Parkinson’s disease

develops psychosis. Why might quetiapine or pimavanserin be
preferred over traditional antipsychotics?

 Answer: Quetiapine and pimavanserin are atypical

antipsychotics that have a lower risk of worsening Parkinson’s
symptoms, as they have minimal dopamine-blocking effects
compared to traditional antipsychotics.
 20. Scenario: A patient with Parkinson’s and psychosis is
prescribed clozapine but develops agranulocytosis. What is a
safer alternative antipsychotic?

 Answer: Quetiapine or pimavanserin would be safer

alternatives as they have a much lower risk of causing
agranulocytosis and are generally well-tolerated in Parkinson’s
patients.

Antiepileptic Drugs (AEDs) and Their Mechanisms

1. Scenario: A 35-year-old female with newly diagnosed generalized tonic-

clonic seizures is prescribed valproic acid. How does valproic acid help
control her seizures?
o Answer: Valproic acid works by increasing the
availability of gamma-aminobutyric acid (GABA), an
inhibitory neurotransmitter, and by inhibiting sodium
channels, thus reducing neuronal excitability and
preventing seizure activity.

2. Scenario: A 45-year-old male with epilepsy reports experiencing drowsiness,

cognitive slowing, and difficulty concentrating after starting carbamazepine.
What might be the cause, and what adjustments should be made?
o Answer: Carbamazepine is a sodium channel blocker
that can cause sedation and cognitive side effects,
particularly in higher doses. The dose should be
reassessed, or an alternative AED with a more favorable
side effect profile, like lamotrigine, may be considered.

3. Scenario: A 60-year-old patient with focal seizures is prescribed lamotrigine.

How does lamotrigine work to prevent seizures?
o Answer: Lamotrigine inhibits voltage-gated sodium
channels, thereby stabilizing neuronal membranes and
preventing the spread of seizure activity. It is particularly
effective in focal seizures.

4. Scenario: A 22-year-old male with epilepsy is started on phenytoin. After a

few weeks, his gums become swollen and inflamed. What could be causing
this, and how can it be managed?
o Answer: Phenytoin is known to cause gingival
hyperplasia as a side effect. Maintaining good oral
hygiene, along with possible referral to a dentist for
periodontal care, may help manage this condition. In
 some cases, switching to a different AED may be
necessary if the side effects are significant.

Monotherapy vs. Polytherapy in Epilepsy

5. Scenario: A 55-year-old patient with epilepsy experiences poor seizure

control despite being on monotherapy with valproic acid. What factors should
be considered when adding a second antiepileptic drug?
o Answer: When adding a second AED, the physician
should consider drug interactions, the patient's seizure
type, and the side effect profile. Options like lamotrigine
or levetiracetam may be considered, depending on the
patient's medical history and tolerance.

6. Scenario: A 25-year-old female with generalized seizures is on polytherapy

with valproic acid and topiramate. She reports feeling increasingly fatigued
and notices cognitive impairments. What might be causing this, and what can
be done?
o Answer: Both valproic acid and topiramate can cause
cognitive side effects, including fatigue and memory
difficulties. Reducing the dose of one or both
medications or switching to a combination of drugs with
a more favorable cognitive profile may improve
symptoms. Consideration of lamotrigine or
levetiracetam might be appropriate.

Special Populations in Epilepsy Treatment

7. Scenario: A 30-year-old pregnant woman with epilepsy has been on

carbamazepine for several years. What concerns should be addressed
regarding her treatment during pregnancy?
o Answer: Carbamazepine is associated with an
increased risk of congenital malformations, particularly
neural tube defects. A review of her treatment plan
should be done, considering alternatives like
lamotrigine, which is considered safer in pregnancy, or
optimizing folic acid intake.

8. Scenario: A 70-year-old male with epilepsy has been prescribed

levetiracetam. How should his treatment be adjusted in light of his age and
renal function?
o Answer: In elderly patients, especially those with renal
impairment, the dose of levetiracetam should be
reduced, as the drug is primarily excreted by the
 kidneys. Regular monitoring of renal function is essential
to prevent toxicity.

Adverse Effects and Toxicity

9. Scenario: A 40-year-old patient with epilepsy on high-dose phenytoin

develops nystagmus and ataxia. What could be the cause of these symptoms,
and how should they be addressed?
o Answer: Nystagmus and ataxia are signs of phenytoin
toxicity, often seen at higher serum levels. The dose
should be reduced, or the medication could be switched
to another AED like lamotrigine or levetiracetam.

10. Scenario: A 50-year-old female with epilepsy on valproic acid presents with
jaundice, abdominal pain, and dark urine. What is the most likely cause, and
what should be done?

 Answer: These symptoms are concerning for valproic acid-

induced liver toxicity. Valproic acid should be discontinued
immediately, and the patient should be evaluated for liver
damage. Alternative treatments like lamotrigine or
levetiracetam may be considered.

Drug Interactions in Epilepsy

11. Scenario: A 28-year-old patient with epilepsy on

lamotrigine is started on oral contraceptives. What interaction
should be monitored?

 Answer: Oral contraceptives may reduce the effectiveness of

lamotrigine by increasing its metabolism through induction of
liver enzymes. A dose adjustment of lamotrigine may be
required to maintain seizure control.

12. Scenario: A 60-year-old male on carbamazepine for

focal seizures is prescribed clarithromycin for an infection.
What interaction should be considered?

 Answer: Clarithromycin can inhibit cytochrome P450

enzymes, increasing carbamazepine levels and potentially
leading to toxicity. Monitoring carbamazepine levels and
adjusting the dose accordingly is recommended.
Status Epilepticus

13. Scenario: A 45-year-old patient presents to the

emergency department in status epilepticus. Which first-line
treatment should be administered to stop the seizures?

 Answer: The first-line treatment for status epilepticus is

intravenous lorazepam or diazepam to terminate the seizures.
Following stabilization, long-term seizure control with drugs
like phenytoin or levetiracetam can be initiated.

14. Scenario: A patient in the emergency room with status

epilepticus is given lorazepam, but the seizures persist. What
should be the next step in management?

 Answer: If seizures persist after lorazepam, second-line

treatments such as phenytoin, fosphenytoin, or valproic acid
should be administered. If seizures continue, general
anesthesia with agents like propofol or midazolam may be
considered.

Newer Antiepileptic Drugs (AEDs)

15. Scenario: A 30-year-old female patient with focal

seizures is prescribed brivaracetam. What makes this drug
distinct from other AEDs like levetiracetam?

 Answer: Brivaracetam is similar to levetiracetam but has a

higher affinity for the synaptic vesicle protein 2A (SV2A). It
has fewer neuropsychiatric side effects, such as irritability and
mood changes, and is often better tolerated than
levetiracetam in some patients.

16. Scenario: A 50-year-old male with epilepsy is started on

eslicarbazepine. What is the mechanism of action of this drug,
and what side effects should be monitored?

 Answer: Eslicarbazepine works by inhibiting sodium channels,

stabilizing hyperactive neuronal membranes, and reducing
seizure activity. Side effects to monitor include dizziness,
somnolence, and a potential increase in liver enzymes.
Seizure Types and AED Selection

17. Scenario: A 25-year-old male presents with generalized

absence seizures. What is the drug of choice for this seizure
type?

 Answer: The drug of choice for absence seizures is

ethosuximide, which works by inhibiting T-type calcium
channels in the thalamus, reducing the hyperexcitability
associated with absence seizures.

18. Scenario: A 7-year-old child with newly diagnosed

epilepsy presents with myoclonic seizures. What AED would be
most appropriate to start?

 Answer: Levetiracetam or valproic acid are often preferred for

myoclonic seizures due to their effectiveness in treating this
seizure type. Lamotrigine may also be an option.