57. Parkinson Disease Flashcards
What is the mechanism of action of entacapone?
A. Dopamine agonist
B. Dopamine replacement therapy
C. Anticholinergic
D. MAOI-B inhibitor
E. COMT Inhibitor
E. Entacapone (Comtan) inhibits the enzyme catechol-O-methyltransferase (COMT), to prevent the peripheral conversion of levodopa by this enzyme. The only reason for using entacapone is to extend the duration of action of levodopa. It should never be prescribed without concurrent levodopa therapy, and is dosed with each dose of the levodopa (such as inSinemet).
What are significant adverse reactions associated with the use of Apokyn? (Select ALL that apply.)
A. Dyskinesias
B. Extreme drops in blood pressure
C. Drowsiness
D. QT-prolongation
E. Nausea and vomiting
A, B, C, D, E. This is a poorly tolerated agent, yet it can be used in patients to provide some mobility in patients with advanced disease. The effect lasts about an hour. In addition to hypotension and severe nausea the drug is a QT-prolongating agent. To help with nausea and vomiting, administer trimethobenzamide (Tigan) 300 mg PO TID or a similar antiemetic, started 3 days prior to the initial dose of apomorphine and continued at least during the first two months of therapy. Other adverse effects of apomorphine include yawning, dyskinesias, somnolence and dizziness.
Herbert is an 88 year-old male with advanced symptoms of Parkinson’s disease. He is using maximum doses of levodopa-carbidopa and pramipexole. Yet, he is having difficulty with the drugs wearing-off and with dyskinetic side effects. The physician is asking for your advice on the use of amantadine in this patient. Your response should include the following advice:
A. Amantadine can cause toxic delirium in patients with reduced renal function.
B. Amantadine cannot be used with levodopa-carbidopa.
C. Amantadine cannot be used with pramipexole.
D. Amantadine is contraindicated in a patient that is 88 years old.
E. Amantadine is used for influenza and other viral infections, not Parkinson’s disease.
A. Amantadine (Symmetrel) is approved for treatment and prophylaxis of influenza A and Parkinson’s disease. It is used for early symptoms (tremor-predominant disease). It is not as effective as the agents the patient is currently using. Use caution in the elderly to adjust the amantadine dose for renal dysfunction; amantadine can induce delirium when overdosed.
A newer formulation of rotigotine is available in a patch formulation. Which of the following statements concerning rotigotine are correct? (Select ALL that apply.)
A. The brand name of the patch is Neupro.
B. It can be used for both Parkinson’s disease and for help with restless leg syndrome.
C. Drowsiness, nausea, dizziness/orthostasis are common side effects; some patients get peripheral edema (primarily swollen ankles).
D. It is applied once weekly; heat sources cannot be placed over the patch.
E. Unlike some other patches, this patch does not need to be removed prior to an MRI.
A, B, C. It is applied once daily (not weekly); heat sources cannot be placed over the patch. It MUST be removed prior to an MRI or it will burn the patient’s skin.
A patient who requires wound treatment has been transferred to a hospital from a skilled nursing facility. He is receiving the following medications: carbidopa-levodopa, ropinirole, amlodipine, and acetaminophen-hydrocodone, as needed. He was given two doses of ondansetron in the past few hours, due to gagging/vomiting. The patient suffers from extreme hypomobility. A feeding tube has been inserted and the medicine team has requested a pharmacist consult for medication administration. The physician inquires if the patient can be given an injection of apomorphine so they can communicate with him at the bedside. The pharmacist replies:
A. If he is given trimethobenzamide now, he can receive apomorphine in one hour.
B. After receiving the antiemetic, he should start with a 0.2 mg dose of apomorphine.
C. He can receive apomorphine now, but he will require careful monitoring of his blood pressure.
D. Apomorphine is currently contraindicated in this patient.
E. After receiving the antiemetic, he should start with a 0.1 mg dose of apomorphine.
D. Apomorphine causes severe nausea and vomiting. Profound hypotension and loss of consciousness have occurred when apomorphine was administered with ondansetron; this patient has received two doses of ondansetron in the past few hours-at present, he cannot receive apomorphine. The concomitant use of apomorphine with drugs of the 5HT3 antagonist class (ondansetron, granisetron, dolasetron, palonosetron, and alosetron) is contraindicated.
Select the correct starting dose for pramipexole immediate-release when used daily for Parkinson’s disease:
A. 1 mg TID
B. 1 mg Q AM
C. 0.125 mg three times daily
D. 1.5 mg three times daily
E. 0.25 mg three times daily
C. Pramipexole is started at 0.125 mg TID, and can be increased slowly to a (maximum) 1.5 mg TID. Alternatively, there is a once-daily XL formulation that is taken in the morning. It is important to increase the dose slowly; the dopamine-agonists can make patients suddenly sleepy. They also can cause or worsen orthostatic hypotension.
A pharmacist will counsel a patient beginning Sinemet. Which of the following are correct counseling statements? (SelectALL that apply.)
A. Do not use this medication if you are taking medicines for depression called isocarboxazid (Marplan), phenelzine (Nardil) or tranylcypromine (Parnate). These drugs must be stopped at least 7 days before starting the Sinemet.
B. If you have an erection that is painful and lasts longer than 4 hours you will need to get emergency medical help.
C. Iron pills should be taken at a different time than this medication.
D. If you have uncontrollable movements, such as in your arms, or with your head or other areas, they could be from this medicine; contact your doctor as soon as possible.
E. This drug can cause your stool to become lighter in color; this is not considered harmful.
B, C, D. The wash-out period between the non-selective MAOIs and drugs in which they interact is 2 weeks, except if you are going from fluoxetine back to a MAOI, then it is 5 weeks. Levodopa can occasionally (rarely) cause priapism. It can cause the urine to become darker (no effect on the stool).
A patient is having a difficult time swallowing pills. He is using carbidopa-levodopa. Which of the following medications is an easier-to-swallow oral formulation of carbidopa-levodopa?
A. Parcopa RapiTab
B. Zelapar ODT
C. Symmetrel
D. Cogentin
E. Comtan
A. Parcopa RapiTab (carbidopa-levodopa) dissolves on the tongue without water. This is useful in dysphagia and can be helpful in reducing nausea.
A patient was started on fluoxetine, pramipexole and clonidine. After some time on these three medications, he began to imagine that his wife was trying to poison his food. He also noticed that the weather was getting worse and felt that he would eventually be washed out into the ocean. Which drug is likely contributing to the development of the patient’s psychosis?
A. Fluoxetine
B. Pramipexole
C. Clonidine
D. All three could be causing this.
E. It is unlikely that any of these can be causing this.
B. Psychological issues, including delusions, can occur after long-term use of levodopa, and (more commonly) with the use of the dopamine agonists ropinirole and pramipexole.
A patient is having a difficult time swallowing pills. He is using selegiline. Which of the following medications is an easier-to-swallow oral formulation of selegiline?
A. Parcopa RapiTab
B. Zelapar ODT
C. Symmetrel
D. Cogentin
E. Comtan
B. Zelapar ODT (selegiline) dissolves on the tongue without water. This is useful in dysphagia.
Benjamin is a 72 year-old male who presents to the clinic with bilateral tremor. He reports that the tremor began on his right side only, and now his writing is so “shaky” that he is having trouble keeping his checkbook. He is scared that the tremor has spread to both sides and he states he doesn’t want that “Parkinsons thing.” Which of the following symptoms would lead to a diagnosis of Parkinson disease?
A. Tremor
B. Problems walking
C. Feeling “stiff” with difficulty making simple movements.
D. Decreased muscle control
E. All of the above
E. The classic symptoms of Parkinson Disease are T-R-A-P for Tremor, Rigidity (rigid arms, legs, face), Akinesia/bradykinesia (lack of movement or slow initiation of movement) and Postural instability (poor balance, which can lead to frequent falls). Other signs that may be present include motor symptoms (freezing at initiation of movement, difficulty swallowing), autonomic symptoms (constipation, bladder incontinence, drooling, reduced eye blinking) and mental symptoms (depression, anxiety, insomnia).
A patient has been prescribed amantadine for Parkinson’s disease. The pharmacist is going to counsel her on the most likely side effects. Counseling should include the following: (Select ALL that apply.)
A. Lightheadedness
B. Seizures
C. Dizziness
D. Hypertension
E. Insomnia
A, C, E. Nausea, dizziness (light-headedness) and insomnia are the most common side effects of amantadine therapy, occurring in 5-10% of patients. A rare, but possible side effect, is livedo reticularis, which is a mottled purplish discoloration of the lower extremities. If this occurs the drug is discontinued. Amantadine can only be given at a reduced dose with impaired renal clearance.
Esther has a history of hypertension, anxiety and Parkinson’s disease (onset 6 years ago). She has just entered a skilled nursing facility. The pharmacist is planning to scan her profile to make sure that her medications are appropriate and that she is not using anything potentially harmful. Choose the medication that is most likely to worsen her movement disorder:
A. Metoclopramide
B. Pramipexole
C. Clonidine
D. Atenolol
E. Ropinirole
A. Metoclopramide (Reglan) is a dopamine blocking agent that can induce movement disorders, especially when overdosed. This is not an uncommon occurrence since the dose must be reduced in renal dysfunction (which is often not done).
Which of the following formulations are useful (and FDA-indicated) for restless leg syndrome? (Select ALL that apply.)
A. Mirapex immmediate-release
B. Mirapex extended-release
C. Requip immmediate-release
D. Requip extended-release
E. Rotigotine
A, C, E. The extended release formulations are not helpful for restless leg, which happens soon after falling asleep. However, the continous patch rotigotine can be helpful.
Select the correct starting dose for ropinirole immediate-release when used daily for Parkinson’s disease:
A. 1 mg TID
B. 1 mg Q AM
C. 0.125 mg three times daily
D. 1.5 mg three times daily
E. 0.25 mg three times daily
E. Ropinirole (Requip) is started at 0.25 mg TID, and can be increased slowly at weekly intervals. Alternatively, there is a once-daily XL formulation that is taken in the morning. It is important to increase the dose slowly; the dopamine-agonists can make patients suddenly sleepy.
