pharmacology OSPE cases CNS

Case 1

Ahmed is a 60-year old architect who designs buildings. His drawings are very detailed and they must be drawn to a specific scale. During the past month he has developed a slight tremor in his right hand that causes some embarr assment but does not interfere with function. He has, however, noticed that his writing and drawing have gotten much smaller, causing problems with his work. His primary care physician has referred him to a neurologist for evaluation. On examination, the neurologist notes some motor rigidity in the right arm. He also observes a slight slowing in the patient’s walk and a reduction in the swing of his arms as he walks.

Q1:What is the diagnosis?

Q2:How should the patient be treated?

Diagnosis .Parkinson’s disease

Lines of treatment

1-Dopamine precursor :L-dopa + Carbidopa

2-COMT inhibitors: Entacapone

3-Dopamine releaser: Amantadine

4-MAO-B inhibitors: Selegiline

5-Dopamine Agonist: - Bromocriptine & Pergolide -Ropinirole &Pramipexole Minor

Approach: Muscarinic Antagonist: Benztropine & Trihexyphenidyl

Case 2

A 72-year-old woman with Parkinson’s disease is taking a medication that is mainly antiviral agents. In Parkinson disease it acts by increasing release of dopamine and blockade of cholinergic receptors.

A. Name this drug ?

B. Name other use/s of this drug?

Amantadine

Other uses

2- anti viral Off lable uses

3- autism

4- ADHD

Case 3

A 58-year-old man with Parkinson’s disease presents to the clinic for follow-up. Recently, he has experienced an increase in his resting tremors. He was wondering if there is a medication that could help these symptoms.

Q1:What is the most appropriate treatment?

Q2:Name common side effect?

Case 3

Benzotropine

Possible side effects of anticholinergics include:

Poor coordination,Dementia,Decreased mucus production in the nose and throat; consequent dry, sore throat,Dry-mouth with possible acceleration of dental caries Cessation of sweating; consequent decreased epidermal thermal dissipation leading to warm, blotchy, or red skin,

Increased body temperature ,Pupil dilation; consequent sensitivity to bright light (photophobia) Loss of accommodation (loss of focusing ability, blurred vision – cycloplegia)

Double-vision Increased heart rate Tendency to be easily startled Urinary retention Urinary incontinence while sleeping Diminished bowel movement, sometimes ileus (decreases motility via the vagus nerve) Increased intraocular pressure; dangerous for people with narrow-angle glaucoma

Case 4

A 62-year-old man complained to his physician of facial grimacing, lip smacking, and rocking of the trunk that occurred1 to 2 hours after taking his prescribed medication. The man, who suffered from Parkinson disease, had been receiving an antiparkinsonian drug for 3 years.

Q1:Which drug most likely caused the adverse effects reported by the patient?

Q2:Name other side effects?

Q3:What are possible drug interactions of this medication?

Case 4

l.dopa

CNS Delusions • Hallucinations • Confusion side effect • Sleep disturbances (insomnia), psychosis Dyskinesia (involuntary movements occurs in 40 to 90% of patients) → due to • fluctuating plasma levels of levodopa. • The dyskinesia can be reduced by lowering the dosage; however, the symptoms of parkinsonism may then reappear. • On-off phenomenon (On= improved mobility & Off=Akinesia or hypomobility) GIT Anorexia, nausea, vomiting (due to stimulation of CTZ) Cardiac arrhythmias (withdraw the drug). • Orthostatic hypotension

Non Desirable interaction

•High protein meal

• Pyridoxine (VitaminB6)

Drug interactions

• Non Selective MAO inhibitors (Phenelzine,Tranylcypromine)→Hypertensive crisis

Desirable

1-Carbidopa Benefits of L-dopa + carbidopa combination:

o Lowers the effective levodopa dose

o Increase availability of levodopa to CNS.

o Reduce dose of levodopa and side effects.

2-COMT inhibitor

Case 5

A 51-year-old woman complained of a resting tremor in her left hand, difficulty in writing, and a distressing sensation of inner restlessness. After careful neurologic examination, a diagnosis was made, and an appropriate therapy was ordered that included a drug acting as an agonist at dopamine D2 receptors in the brain.

Q1:Name 2 drugs acting as dopamine receptor agonist?

Q2:Enumerate adverse effects of such medications?

Bromocryptine , pramipexole

Side effect

CNS Delusions

• Hallucinations

• Confusion

• Sleep disturbances (insomnia),

psychosis

GIT

Anorexia, nausea, vomiting (due to stimulation of CTZ

CVS

Cardiac arrhythmias (withdraw the drug).

• Orthostatic hypotension

Case 6

A 75-year-old diabetic man with Parkinson disease complained of worsening of his tremor and rigidity in his arms and legs. His Parkinson disease had been responding well to a treatment with levodopa/carbidopa and amantadine, and his diabetes had been controlled by glyburide and metformin. Recently, metoclopramide was prescribed to manage diabetic gastroparesis.

Q1:Explain why combination of carbidopa with L dopa is a good combination?

Q2: is it wise to prescribe metoclopramide for this patient?

1- Explain why combination of carbidopa with L-dopa is a good combination? E.g Carbidopa ,

to inhibit peripheral conversion of L-dopa to dopamine in GIT and other peripheral tissues.

Thus, increasing T1\2. Benefits of L-dopa + carbidopa combination:

o Lowers the effective levodopa dose

o Increase availability of levodopa to CNS.

o Reduce dose of levodopa and side effects -

2- is it wise to prescribe metoclopramide for this patient?

No, because it block dopamine receptor

Case 7

Mr. A, a 65-year-old male with a 12-year history of Parkinson’s disease, presents to the neurology clinic with severe “off” episodes despite being on long-term levodopa/carbidopa therapy. His wife reports that during these episodes, he suddenly becomes rigid, immobile, and unable to speak or walk, lasting for about 30–60 minutes. Increasing levodopa doses caused disabling dyskinesias.The neurologist considers adding apomorphine to his treatment plan.

Q1:Which of the following best explains the rationale for using apomorphine in this patient?

Q2 : List route of adminesteration of this drug?

Q3: List side effect of this drug ?

Answer:

B.

It is a dopamine agonist used as a rescue therapy for sudden “off” episodes --- Explanation: Apomorphine is a potent dopamine D1/D2 receptor agonist.

It is administered subcutaneously due to poor oral bioavailability. Its main indication is “rescue therapy” for sudden, severe, and unpredictable “off” episodes in advanced Parkinson’s disease when oral drugs fail to work quickly. Onset of action: within 10 minutes, making it useful for immobility attacks.

Side effects include severe nausea/vomiting (therefore pretreatment with antiemetics like domperidone is recommended), orthostatic hypotension, and somnolence.

Case 1

A 53-year-old man comes to clinic for depression. He has had decreased interest and a depressed mood for the past 6 months. He also smokes half a pack of cigarettes a day and thinks that if he could quit, that would help his mood as well. What is the most appropriate treatment for his depression and cessation of smoking?

Q1: What is the mechanism of action of this drug?

Q2:When drug cosider fail in treatment ?

bupropion

norepinephrine and dopamine reuptake inhibtor when two or more drugs from different classes have been tried at this point

Case 2

A 43-year-old woman with a history of breast cancer and depression presents to her physician for treatment. She complains of feeling sad and worthless and loss of appetite

Q1: Which drug would be best for this patient?

Q2: Advantges of this drug?

antidepressant in cancer patient :

Mirtazapine Because

1-It improves appetite.

2-↓ nausea & vomiting (by 5-HT3 blocking).

3- ↑ body weight (5-HT2C blocking effect).

4- Sedation (H1 blocking effect).

5- Less sexual dysfunction (by 5-HT2 blocking).

6- Has no anti-muscarinic effect

Case 3

A 43-year-old man went to his physician complaining of difficulty in maintaining an erection during intercourse. Past history of the patient was significant for an episode of ventricular tachycardia 1 year earlier. He was recently diagnosed with major depressive disorder and started a drug treatment 2 weeks ago

Q1:Which drugs most likely caused the symptom reported by the patient?

Q2:How can doctor do in this case ?

TCA,SSRIS , SNRIs

Doctor must change to another drug as mirtazpine , add sildenafil

Case 4

A 34-year-old man suffering from a major depressive disorder had started a therapy with paroxetine, but 1 month later his symptoms were minimally improved, and his psychiatrist decided to add a drug to the treatment. The prescribed drug has a complex molecular mechanism of action that includes a blockade of presynaptic α2 receptors.

Q1:Which drug was most likely given?

Mirtazapine

Case 5

A 17-year-old girl was admitted to an eating disorder clinic with a 3-month history of binge eating and vomiting and purging episodes occurring from twice per week to four times a day. After physical examination and lab tests, psychotherapy and a drug treatment were prescribed.

Q1:Which drug appropriate for this patient?

Q2:List other uses of this drug?

Q1:Which drug appropriate for this patient? Fluoxetine

Q2:Name other uses of this drug? Obessisive compulsive, depression ,panic attack, premature ejaculation

Case 6

A 43-year-old woman with a history of fibromyalgia and depression presents to her primary care physician for treatment. She complains of feeling sad and worth- less in addition to multiple somatic complaints.

Q1:Which drugwould be best for this patient?

Q2:What is mechanism of action?

Q1:Which drugwould be best for this patient? Duloxetine

Q2:What is mechanism of action? Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs)

Case 7

A 47-year-old woman with depression develops severe muscle rigidity, hyperthermia, hypertension, and confusion after taking fluoxetine with another antidepressant.

Q1:What is the likely condition?

Q2: Enumerate lines of treatment ?

Serotonin syndrome Explanation: Combination of SSRIs with MAO inhibitors or other serotonergic drugs can cause serotonin syndrome (triad: neuromuscular hyperactivity, autonomic instability, mental status change).

Ttt : stop drug , symptomatic ttt , diazepam

Case 1

A 22-year-old woman is brought in the emergency department via ambulance because of a suicide attempt. she called her boyfriend saying that she took ahandful of sleeping tablets. On examination, she appears lethargic, but moves all her extremities to painful stimuli. Her blood pressure is 110/70 mm Hg, heart rate is 80 bp/m, and oxygen saturation is 99 percent. Her pupils are of normal size,she was given an intravenous bolus of dextrose and an ampoule of naloxone without response. Her boyfriend brings in the bottle of sleeping medication which reads “lorazepam.”

Q1. What is the danger of an overdose with this class of medication?

Q2. What is the cellular mechanism of action of this class of medication? .

Q3.What pharmacologic agent can be used to treat this patient, and what is its mechanism of action?

Q1. What is the danger of an overdose with this class of medication? respiratory and cardiac depression.

Q2. What is the cellular mechanism of action of this class of medication? binding toBZreceptorsin the brain→ enhance GABA action on the brain→ chloridechannels opening→ ↑chloride influx to the cell→ hyperpolarization→ more difficultto depolarize→reduction of neural excitability.

Q3.What pharmacologic agent can be used to treat this patient, and whatisitsmechanism of action? Flumazenil → It is Selective, benzodiazepine receptor antagonist. bind competitively to GABAreceptors replacingBDZ

Case 2

A 70-year-old man consults his family physician for the problem of failing to fall asleep occasionally (3-4 times in a month) for the past few months. He usually sleeps well and has a 6-7 hour sleep duration. However, on certain nights he keeps lying in bed for 2-3 hours before getting sleep. Such episodes are unpredictable, and he cannot relate them to any disturbance, anxiety, worry or physical illness. He has tried relaxing, getting up and walking around or reading, but nothing helps. As a result, next day he feels lethargic, impaired, unable to concentrate and has poor creativity. He requests a sleeping pill that he can take occasionally when he fails to fall asleep.

Q1:Can he be prescribed a hypnotic for occasional use?

Q2: If so, which drug would be suitable for late night intake without next morning sedation?

Q1-Since this patient does not require a hypnotic on regular basis, there is no identifiable cause of occasional sleep onset difficulty and he has tried non-drug measures, he can be prescribed a hypnotic to be kept handy for use when required. Because there is only sleep onset difficulty, and he will take the drug only later at night (after going to bed as usual), he needs a short acting hypnotic which would be free of residual effect next morning.

Q2-Zaleplon would be suitable for this patient, as it has a short t½ (1 hour), does not cause next morning drowsiness, day time anxiety or rebound insomnia. Tolerance is unlikely to develop, because use is going to be occasional.

Case 3

A 42-year-old man recently diagnosed with generalized anxiety disorder had started a treatment with sertraline, but the drug caused some sexual dysfunction, and the psychiatrist decided to switch to a short course of alprazolam.

Q1:What is molecular actions alprazolam in the patient’s disorder?

Q2 :What is most common of side effect of this drug ?

Alprazolam works by enhancing GABA, a brain chemical that calms nerve activity, easing anxiety.

Its most common side effect is drowsiness or sedation, but it can also cause dizziness and, less often, memory issues.

Case 4

A 63-year-old woman complained to her physician of difficulty in falling asleep. She denied nocturnal insomnia or early awaking. The doctor prescribed ramelteon, one tablet at bedtime.

Q1:What is the molecular actions most likely mediated the therapeutic effect of the drug?

Q2:Name main side effect of this drug ?

Ramelteon is a melatonin receptor agonist. It selectively binds to MT₁ and MT₂ receptors in the suprachiasmatic nucleus (SCN) of the hypothalamus. MT₁ activation → promotes sleep onset. MT₂ activation → regulates circadian rhythm (sleep–wake cycle). Unlike benzodiazepines and Z-drugs, it does not act on GABA-A receptors, so it has no dependence or abuse potential.

Side Effects Most are mild and uncommon: CNS: dizziness, fatigue, somnolence. Endocrine: increased prolactin levels, decreased testosterone. GI: nausea, diarrhea. Others: headache, worsening depression in susceptible patients (rare).

Case 5

A 49-year-old woman complained to her physician that she could get to sleep when she went to bed but woke up several times during the night and never felt refreshed in the morning. The woman had no medical problems and took no medications.

Q1:Which drugs would be most appropriate for this patient?

Q2: Mechanism of action of this drug?

The patient wakes up multiple times at night and never feels rested.

. The most appropriate drugs are non-benzodiazepine hypnotics like eszopiclone or zolpidem, which help improve sleep maintenance.

These drugs work by enhancing GABA-A receptor activity, increasing inhibitory neurotransmission to promote sleep.

Case 6

A 40-year-old woman with chronic insomnia also has depression.heavy smooker.

Q1 which drug is more appropriate in this case ?

Q2 Explain ?

Answer: Use sedating antidepressant (e.g., trazodone, mirtazapine).

Explanation: In depressed patients with insomnia, sedating antidepressants are preferred since they treat both depression and sleep disturbance without risk of dependence.

Case 7

A 50-year-old man with chronic insomnia takes clonazepam every night. He reports daytime sedation and poor concentration at work.

What is the most appropriate mangment and why ?

Answer: Switch to a shorter-acting hypnotic (temazepam, zolpidem) or taper off completely.

Explanation: Long-acting benzodiazepines cause residual daytime drowsiness → unsuitable for working individuals.