Pharmacology Flashcards
(40 cards)
An otherwise healthy 56 year-old female presents to your outpatient clinic after referral from her primary care physician. The patient reports a 4-month history of episodic sharp, severe, lightning-like pain in her left jaw that has become more frequent recently. She describes 10-second episodes of pain along her jawline on the left side, occasionally brought on by brushing her teeth or chewing food. She otherwise denies all symptoms. Her dentition is pristine. She has no pain over her temporomandibular joints bilaterally. You prescribe the first-line medication for her condition; what is the mechanism of action of this drug?
A Depletion of substance P
B Sodium channel inhibition
C L-type calcium channel blockade
D COX-2 inhibition
Answer: B
Explanation:
• This patient is likely suffering from trigeminal neuralgia, as evidenced by the episodic, severe, lightning-like pain in the distribution of cranial nerve V.
• It is also noted that she does not have pain over her temporomandibular joints (TMJ) and no evidence of dental caries, making TMJ pain and pain related to dental cary/abscess less likely.
• First-line treatment for trigeminal neuralgia is carbamazepine, which acts via sodium channel inhibition on neurons.
• COX-2 specific inhibitors such as meloxicam and celecoxib may act to decrease inflammation in this patient, but they are not first-line treatments for this diagnosis.
• Capsaicin works via depletion of substance P.
• Gabapentin, via L-type calcium channel blockade, can be effective in neuropathic pain but is not used first line for this condition
Which of the following is the most likely side effect of taking nortriptyline?
AInsomnia
BDiarrhea
CDry mouth
DExcessive urination
Answer: C
* TCAs such as amitriptyline and nortriptyline inhibit the reuptake of serotonin and norepinephrine. * They also have anticholinergic side effects, including dry mouth, constipation, and urinary retention. * Furthermore, sedation is a commonly reported side effect, and some patients use TCAs to improve their sleep.
A 49 year-old male with history of untreated depression, poorly controlled diabetes, and insomnia presents for evaluation of burning in bilateral feet up to the ankles. She states it began about 1 year ago with a sensation of “bee-stings” on her toes, and since that time it has gradually ascended to the level of her ankles. Electrodiagnostics reveal length-dependent peripheral neuropathy. The patient asks for medication for his symptoms. Chart review reveals allergies to multiple medications including gabapentin and duloxetine. You decide to trial amitriptyline, and warn the patient of possible side effects including all of the following except: ASomnolence BConstipation CUrinary retention DExcessive salivation
Answer: D
Explanation:
• Tricyclic antidepressants such as amitriptyline have wide-range of potential side effects, which can be attributed to the medication acting at a number of receptors and pathways.
• One of the receptors that tricyclic antidepressants block are muscarinic/cholinergic receptors; therefore, anticholinergic side effects including dry mouth (not excessive salivation), urinary retention, and constipation are all possible side effects.
• The side effect of somnolence is common; many physicians will try to use tricyclic antidepressants to treat neuropathic pain in addition to acting as a sleep-aid.
NSAIDs (nonsteroidal anti-inflammatory drugs) reduce pain by reducing the production of which of the following compounds? ANMDA receptors BLeukotrienes CProstaglandins DCOX enzyme
Answer: C
Explanation:
• NSAIDs inhibit the COX enzyme, which reduces COX’s production of prostaglandins.
• Prostaglandins mediate inflammation. Thus, inflammatory pain is reduced by using NSAIDs.
A 40 year-old female presents to you with the chief complaint of feeling an intensely uncomfortable urge to get out of bed at night and walk around. She feels only marginally better when she gets back into bed. What is an appropriate treatment for this patient?
A All of the listed choices are correct
B Levodopa-carbidopa
C Ropinirole
D Pramipexole
Answer: A
Explanation:
• All of the above are dopaminergic agents, which are indicated in the pharmacologic treatment of Restless Legs Syndrome (RLS).
• Be sure to rule out iron deficiency as a cause of RLS before initiating treatment.
A 42 year-old female is evaluated in your inpatient rehabilitation unit. Therapists are concerned that her tremors are interfering with her functional progress. On examination, you notice no tremor at rest, but when you ask her to point to different pictures on a board in front of her, her aim is poor and she often misses her target, overshooting and undershooting it. The therapists have tried wrist weights, and these have not benefited her. What is the next best step for treating her tremor?
A Clonazepam
B Deep brain stimulator
C Elbow-wrist-hand orthosis
D Reassurance
Answer: A
Explanation:
• This patient presents with tremor during coordination of limbs, notably with attempting to accurately point to a spot in space, and demonstrating dysmetria in the process.
• This is known as an intention tremor and is associated with cerebellar dysfunction.
• Failing conservative therapy, oral medications should be initiated to treat intention tremor.
• Clonazepam has been shown in the literature to be effective for cases of intention tremor.
Zolgensma (onasemnogene abeparvovec-xioi) is an FDA-approved gene therapy to treat which of the following conditions?
A Spinal muscular atrophy (SMA)
B Friedreich ataxia
C Becker muscular dystrophy
D Duchenne muscular dystrophy
Answer: A
Explanation:
• Zolgensma (onasemnogene abeparvovec-xioi) was FDA-approved on 5/24/2019 as gene therapy for patients under 2 years age with SMA.
• This medication is given once intravenously, and is intended to replace the mutated SMN1 gene in these patients, creating functional SMN protein and improving motor function while preventing disability progression.
Which of the following medications functions as an N-methyl-D-aspartate receptor (NMDA receptor) antagonist?
A Methadone
B Oxycodone
C Morphine
D Fentanyl
Answer: A
Explanation:
• Of the listed medications (all opioids), methadone also functions as an NMDA antagonist, which helps to treat pain in addition to its opioid activities.
Tizanidine’s mechanism of action includes which of the following?
A Alpha-2 antagonist
B Alpha-2 agonist
C Alpha-1 antagonist
D Alpha-1 agonist
Answer: B
Explanation:
• Tizanidine stimulates alpha-2 receptors; this stimulation then inhibits the spinal reflex arc, and is useful for treating spasticity.
Which of the following receptors, when stimulated, increases presynaptic chloride influx into the neuron?
A Alpha-2
B GABA-B2
C GABA-B1
D GABA-A
Answer: D
Explanation:
• The GABA-A receptor causes presynaptic chloride influx into the axon.
• The GABA-B1 receptor inhibits presynaptic calcium influx into the neuron.
• GABA-B2 increases postsynaptic potassium conductance out of the neuron.
• All of these effects serve to reduce synaptic transmission of action potentials.
• Tizanidine binds to alpha-2 receptors to stimulate them, which inhibits the spinal reflex arc.
Mirabegron promotes urine storage in the bladder by stimulating which of the following receptors?
A Beta-3
B Beta-2
C Alpha-2
D Alpha-1
Answer: A
Explanation:
• Mirabegron is a Beta-3 receptor agonist, which is theoretically very selective for the bladder wall, and promotes urine storage.
A 34 year-old male presents to your movement disorders clinic for neck pain. On examination you note his head and neck are always drooping, directed down at the floor. When asked to raise his head, he says, “I can’t. It hurts.” You attempt to extend his neck and meet a great deal of passive resistance in his muscles, although you are slowly able to correct his posture. What is the next best step in management?
A Botulinum toxin injections
B Baclofen
C Dantrolene
D Physical therapy
Answer: A
Explanation:
• This patient presents with cervical dystonia manifesting as a “head drop”, which is the result of bilateral sternocleidomastoid (SCM) dystonic contraction.
• Botulinum toxin injections are first-line therapy for cervical dystonia and should be trialed in this patient to improve his pain and head/neck posture.
Which of the following medications would be most appropriate to increase arousal and attention in a patient with a history of traumatic brain injury and post-traumatic epilepsy? ADonepezil BAmantadine CMethylphenidate DModafinil
Answer: C
Explanation:
• Methylphenidate has the best evidence for NOT lowering the seizure threshold (i.e. not increasing seizure risk) when used as a neurostimulant.
A 52 year-old female presents with bilateral knee pain of gradual onset for the past 7 months. She has felt fatigued with occasional fever. She also notes 90 minutes of knee stiffness when she wakes up. Knee x-rays reveal symmetric medial and lateral compartment narrowing. Which of the following is the next best step in treatment?
A Infliximab
B NSAIDs
C Corticosteroids
D Physical therapy
Answer: A
Explanation:
• Disease-modifying antirheumatic drugs (DMARDs) are the key, most important treatment in rheumatoid arthritis in order to prevent longterm sequelae and disability from the disease. The only DMARD listed here is infliximab. Other DMARDs are methotrexate, hydroxychloroquine, sulfasalazine, etanercept, and adalimumab. NSAIDs, corticosteroids, and PT are very useful in rheumatoid arthritis, but the initial key treatment should be a DMARD.
Which of the following medications is FDA-approved to treat diabetic peripheral neuropathic pain?
A Duloxetine
B Amitriptyline
C Tramadol
D Gabapentin
Answer: A
Explanation:
• Duloxetine and Pregabalin are FDA-approved to treat pain due to peripheral neuropathy in diabetes.
A 52 year-old male who was previously active and healthy begins to notice muscle twitching and difficulty swallowing salivary secretions over the course of 2 months. He then begins to notice some weakness in his right arm and left leg. Electrodiagnostic studies reveal probable amyotrophic lateral sclerosis. He is started on riluzole by his neurologist. At his initial consultation with you, he asks you about the mechanism of riluzole. You respond with:
A Riluzole blocks glutamate action in the central nervous system
B The mechanism is unknown
C Riluzole is an anticholinesterase
D Riluzole is a dopamine agonist
Answer: A
Explanation:
• Amyotrophic lateral sclerosis (ALS) is a progressive disease of upper and lower motor neurons. The median survival rate is 2-3 years after diagnosis, however the median survival rate is 1 year after diagnosis in those with bulbar symptoms.
• Treatment consists of physical therapy and submaximal exercise in addition to consideration of assisted ventilation and early nutritional intervention to supplement calories.
• Riluzole is an antiglutamate medication that has been shown to slow disease and prolong ventilator time.
Which of the following medications stimulates the bowel wall to induce peristalsis?
A Lactulose
B Polyethylene glycol
C Senna
D Docusate
Answer: C
Explanation:
• Docusate is a stool softener. Senna is a stimulant that stimulates the bowel wall to induce peristalsis. Polyethylene glycol and lactulose are osmotic laxatives.
Which of the following medications enhances endogenous dopamine release in the brain?
A Amantadine
B Bromocriptine
C Modafinil
D Methylphenidate
Answer: A
Explanation:
• All of the listed medications are useful in serving as neurostimulation in patients with decreased arousal, and all of them act to increase dopaminergic effects in the brain.
• Amantadine potentiates endogenous dopamine release in the brain in order to achieve this.
• Methylphenidate is a norepinephrine-dopamine reuptake inhibitor.
• Modafinil’s mechanism is not entirely understood, but it may be related to dopamine reuptake inhibition.
• Bromocriptine is a D2 receptor agonist.
As a new PM&R resident, you are rounding with your attending, an upper-level resident, and a medical student. You stop outside of a patient’s room who complains of significant numbness and tingling in a stocking-glove fashion. Chart review reveals significant peripheral neuropathy findings on EMG, believed to be a result of uncontrolled diabetes. The patient has tried and had side effects with typical oral medications for neuropathic pain including gabapentin, pregabalin, duloxetine, and amitriptyline. The patient is interested in trialing a medicine his friend recommended, topical capsaicin, but wants to know more about its mechanism of action; your attending asks you to explain the mechanism of action to the patient. You respond with:
A Capsaicin inhibits PLA-2 enzyme
B Capsaicin depletes substance P, thereby decreasing pain transmission
C Capsaicin blocks L type calcium channels in the central nervous system
D Capsaicin inhibits sodium channels on neurons
Answer: B
Explanation:
• It is important to not only understand the indications for certain medications, but also how they work.
• Capsaicin acts by depleting substance P from nerve endings; substance P is a neuropeptide that has many roles, one of which is functioning as a neurotransmitter and modulator of pain.
• Carbamazepine’s mechanism of action is inhibition of sodium channels on neurons.
• L type calcium channel blockade in the central nervous system is the mechanism of gabapentin (and pregabalin, which is structurally very similar).
• Inhibition of Phospholipase A-2 (PLA2) enzyme is accomplished by corticosteroids.
Which of the following is the correct mechanism of action for gabapentin?
A Sodium channel antagonist
B L-type calcium channel antagonist
C Serotonin-norepinephrine reuptake inhibitor
D NMDA receptor antagonist
Answer: B
Explanation:
• Gabapentin functions as an L-type calcium channel antagonist in the central nervous system (CNS).
Which of the following enzymes produces prostaglandins which protect the stomach lining?
A PLA-2
B PLA-1
C COX-2
D COX-1
Answer: D
Explanation:
• COX-1 produces protective prostaglandins for the stomach lining.
• Thus, inhibition of the COX-1 enzyme by NSAID drugs (such as ibuprofen) can increase the risk of gastric ulcer development.
• Selective inhibition of COX-2 (meloxicam, celecoxib) is theorized to reduce inflammation, but also protect the stomach lining by preserving COX-1 function.
Which of the following medications has been shown to improve survival by a few months in patients with amyotrophic lateral sclerosis (ALS)?
A Riluzole
B Pramipexole
C Amantadine
D Pyridostigmine
Answer: A
Explanation:
• Riluzole is indicated for ALS in order to improve survival by a few months.
A 43 year-old male is admitted to the ICU with a traumatic brain injury (TBI). Neurosurgery has placed an intraventricular ICP catheter to monitor his intracranial pressure. The patient’s ICP is consistently noted at 30 mm Hg, despite elevating the head of the bed combined with forced hyperventilation and hypothermia protocols. What is the next best step?
A IV propranolol
B IV labetalol
C IV enalapril
D IV mannitol
Answer: D
Explanation:
• Initial pharmacologic therapy for reducing intracranial pressure (ICP, goal < 20 mm Hg) is an IV hypertonic solution such as IV mannitol.
• IV diuretics such as acetazolamide would also be indicated.
Approximately how long is the expected duration of action for botulinum toxin injections?
A 6 months
B 3 months
C 2 months
D 1 month
Answer: B
Explanation:
• Botulinum toxin injections typically last approximately 3 months.
• Thus, injections are frequently scheduled every 3 months.
