What is the mechanism of action of entacapone?
A. Dopamine agonist
B. Dopamine replacement therapy
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.)
B. Extreme drops in blood pressure
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
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?
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
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?
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, 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 (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
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.
Benjamin was prescribed levodopa-carbidopa 25/100 CR mg TID. The physician told him that he can cut the dose in half if he cuts directly on the score line. He is asking the pharmacist if they sell tablet cutters. How should the pharmacist respond?
A. If he is not using the medication in full three times daily, he will still need to make sure he gets at least 70 mg of the carbidopa.
B. The pharmacist should recommend levodopa without carbidopa.
C. The pharmacist should tell him that the medication cannot be crushed, chewed or cut.
D. The pharmacist should recommend entacapone instead.
E. If he is going to cut the medication, he should do it with a knife instead.
A. Levodopa-carbidopa comes in many dosage forms to enable the prescriber to match the levodopa dose to the movement disorder, while keeping the carbidopa dose in the correct range. Common formulations include 10/100, 25/100 (often given TID for initial therapy), 25/250, and in controlled-release dosages of 25/100 and 50/200. This is one of the few medications where the controlled-release formulation can be cut-but only right down the middle at the score line. It will remain controlled-release.
Which of the following are side effects associated with levodopa/carbidopa therapy? (Select ALL that apply.)
B. Orthostatic hypotension
C. Urine discoloration
D. Dyskinetic movements, such as arm flailing
A, B, C, D. The most common side effects of levodopa therapy are dyskinesias (occasional, involuntary movements). Counsel the patient that they may experience nausea, orthostatic hypotension (a drop in blood pressure when they move from sitting to standing, which causes dizziness) and hypotension. Urine discoloration may seem harmless, but it can stain clothing and scare the patient.
A patient is taking 10/100 Sinement IR when he wakes up, and 25/250 Sinemet SR TID. Choose the correct statement:
A. This is so he can eat lunch.
B. This is not correct prescribing.
C. This is due to levodopa tolerance.
D. This is due to levodopa physiological adaptation.
E. This is so he can eat breakfast.
B. This is to have enough medicine in his system to get going in the morning, and to be able to eat his breakfast. The SR has a slower onset. This is not uncommon.
A patient is prescribed selegiline 10 mg BID for Parkinson's disease tremor. He is not using any other medications for this condition. You contact the prescriber to report the following errors: (Select ALL that apply.)
A. This medication is dosed 5 mg QAM or 5 mg with breakfast & 5 mg with lunch; the dose is too high and this could cause dangerous drug interactions and cause insomnia.
B. The brand name is Azilect.
C. He should be using metoclopramide.
D. This medication has only been shown to provide benefit when levodopa/carbidopa is used concurrently.
E. There are no errors with this prescription.
A, D. Selegiline (Eldepryl) is used as adjunctive therapy with levodopa/carbidopa in patients who exhibit a decline in response to levodopa/carbidopa therapy. Selegiline is not used alone for this condition. The drug is activating and is not given at bedtime; the correct dose is 5 mg QAM or 5 mg with breakfast & 5 mg with lunch. It should be kept at selective doses for MAO-B. Occasionally a patient is using up to 15 mg a day, which appears okay, but is not indicated.
A pharmacist receives a prescription for Requip. Which is the generic substitution?
D. The generic name of Requip is ropinirole.
Counseling for levodopa should include the following: (Select ALL that apply.)
A. Separate the medicine from other medications.
B. Separate the medicine from iron pills.
C. If possible, separate the medicine from protein-rich foods.
D. Separate the medicine from calcium supplements.
E. Always take at bedtime.
B, C. Levodopa-carbidopa (Sinemet) should be separated from iron (not calcium) supplements. Technically, the drug should also be separated from protein-but practically this is often not possible.
Mary has Parkinson Disease and uses Sinemet and Mirapex to help control her symptoms. Last night at the bridge club Mary accused her old friend of cheating. The friend's new boyfriend got upset and knocked the card table over. This unfortunate event resulted in the police being called in and poor Mary was taken to the hospital for observation. The medical resident decides that Mary should receive an antipsychotic. Which medication would carry the lowest risk of worsening her Parkinson symptoms?
C. Haloperidol (Haldol) is a strong dopamine blocker and can cause severe movement disorders. The older, typical antipsychotics all have a high risk of movement disorders. Of the newer agents, iloperidone (Fanapt) and quetiapine (Seroquel) have lowest risk [along with clozapine (Clozaril), which also has low risk but is reserved for refractive cases]. Quetiapine is the antipsychotic of choice in Parkinson's disease.
Which of the following agents must be dose-adjusted for renal insufficiency? (Select ALL that apply.)
A patient takes carbidopa-levodopa 25/250 TID. It began to wear off and the prescriber added on entacapone 200 mg daily. Is this addition correct?
A. Yes; the patient is using levodopa.
B. No, entacapone is a replacement for levodopa.
C. No, this drug can cause liver toxicity; it is safer to use tolcapone.
D. No, the dosing regimen is incorrect; it should be 200 mg with each dose of levodopa.
E. No, the dosing regimen is incorrect; it should be 300 mg with each dose of levodopa.
D. The dose is always the same: 200 mg of entacapone with each dose of levodopa, up to 8 tablets of entacapone per day (1600 mg max/day). Entacapone and levodopa-carbidopa come in a combination product called Stalevo.
A patient gave the pharmacist a prescription for Tasmar 100 mg #90. Which of the following is an appropriate generic substitution for Tasmar?
E. The generic name of Tasmar is tolcapone.
Annie is a patient with a long history of psychosis and anxiety who is presenting to the doctor’s office with a swinging, rolling motion in her neck that is causing her pain and embarrassment. Which of Annie’s medications could be contributing to the movement disorder?
B. The phenothiazines, including fluphenazine, chlorpromazine, thioridazine and prochlorperazine are dopamine-blockers which can cause movement disorders. Notice the drug names end in -azine.
Margie is a 78 year-old female who has been diagnosed with hypertension, constipation-predominant IBS and mild memory impairment. She presents to her doctor with symptoms of early Parkinson's disease. The physician wishes to avoid dopamine therapy, as he believes it will cause too many dyskinesias for the patient. He prescribes benztropine 1 mg BID. Choose the correct statements: (Select ALL that apply.)
A. This will worsen her constipation
B. This will worsen her memory impairment
C. This will worsen her hypertension
D. This will not worsen any of her existing conditions
E. This drug will cause extrapyramidal symptoms
A, B. Benztropine (Cogentin) has two indications: for adjunctive therapy in Parkinson's disease, and for prevention of extrapyramidal symptoms (painful dystonic reactions) when using antipsychotic drugs such as phenothiazines and haloperidol. Side effects from this class of drugs include peripheral anticholinergic side effects (constipation, urinary retention, blurred vision, dry mouth) and central anticholinergic side effects (drowsiness, confusion, cognitive impairment). Centrally-acting anticholinergics are not acceptable to use in eldery patients due to the side effect profile.
A patient takes levodopa-carbidopa 25/250 TID. It began to wear off and the prescriber added on entacapone 200 mg TID. However, the patient could not pay for the brand medication and the prescriber changed the entacapone to tolcapone. What lab must be monitored with the use of tolcapone?
A. BUN, serum creatinine
B. Sodium and bicarbonate
C. Tolcapone (Tasmar) is an older formulation in the same class as entacapone. It is not used much due to the risk of liver toxicity, but it has occasionally been used when the patient cannot afford entacapone (which works in a similar manner but does not have the same risk for liver damage as tolcapone.) The patient should be counseled on symptoms of liver damage. What should really happen is that the drug should be changed to entacapone, which became available as a generic recently. Or, the combination of entacapone+levodopa+carbidopa (Stalevo) is also available as a generic.
A patient is starting on pramipexole therapy. Which of the following are important counseling points? (Select ALL that apply.)
A. It is possible that you could fall asleep while doing normal activities such as driving a car, doing physical tasks, or using hazardous machinery while taking this medicine.
B. Alcohol can increase the risk of side effects while taking this agent.
C. Opioid pain relievers can help mitigate the adverse effects of this agent.
D. You may feel dizzy, nauseated, sweaty or faint, when first standing up from sitting or lying down; stand up slowly, holding onto a chair or rail.
E. The dose may need to be increased, but it will be at least a week between dose increases
A, B, D, E. These drugs require a slow (not more than weekly) dose titration due to sedation and dizziness. The risk will be higher if the patient is using other medicines that cause sleepiness, including alcohol and pain medicines.
A patient is using rasagiline therapy for early-onset Parkinson's disease. The patient should be counseled to avoid certain foods while using this medicine. These foods include:
A. Aged cheeses
B. Pickled herring, yeast extract
C. Air-dried meats, sauerkraut, soy sauce
D. Some red wines and some beers
E. All of the above
E. Hypertensive crisis (a dangerous rise in blood pressure) could occur if rasagiline is combined with any of the foods listed above; these are all high in tyramine. Foods can become high in tyramine when they have been aged, fermented, pickled or smoked.
A pharmacist receives a prescription for Requip. The patient is instructed that the dose may be increased, but at no more than weekly intervals. Why do the dopamine agonists require a slow dose titration?
A. Due to the risk of rash
B. Due to the risk of sudden sleep attacks, dizziness and syncope
C. Due to bradycardia
D. Due to the risk of acute psychosis
E. Due to the risk of a hypersensitivity reaction
B. Dopamine agonists must be carefully titrated (at no more than weekly intervals) due to the risk of excessive sedation (including falling asleep during normal activities, such as driving). Patients should not be driving a car when they start the medication, and during any dose titration, until they are sure they can drive safely.
A patient has been prescribed rasagiline for add-on benefit to the levodopa-carbidopa he has been using. The patient injured his back several years ago and has been using cyclobenzaprine and tramadol. Can the patient receive rasagiline?
A. Yes; if the dose is selective for MAO-B.
B. Yes; the rasagiline can be used alone or in combination with levodopa in this or any other patient.
C. Yes, if he has wearing off from the levodopa.
D. No, because rasagiline is contraindicated with many drugs, including cyclobenzaprine and tramadol.
E. No, because rasagiline is contraindicated with levodopa.
D. A newer monoamine oxidase inhibitors (MAOI), rasagiline has been shown to provide benefit alone, or in combination with levodopa/carbidopa. Rasagiline is contraindicated with various drugs, including, tramadol, methadone, propoxyphene, dextromethorphan, St. John's wort, cyclobenzaprine and other MAOIs. Concurrent use could result in coma and/or death.
An elderly gentleman with new-onset Parkinson's disease presents to the pharmacy with a prescription for carbidopa-levodopa 10/100 mg TID. The pharmacist contacts the physician to report the following prescribing error:
A. The dose of levodopa is too high for initial treatment.
B. The dose of levodopa is too low for initial treatment.
C. The dose of carbidopa is too low.
D. The dose of carbidopa is too high.
E. The dose of both components is fine; no call is required.
C. When prescribing carbidopa-levodopa (Sinemet), the carbidopa component should be within the range of 70-100 mg. This is important for two reasons: a minimum dose is required for effectiveness, and higher doses will cause nausea. The carbidopa prevents the peripheral (outside of the CNS) breakdown of levodopa by the enzyme decarboxylase. Carbidopa is a decarboxylase inhibitor.
A patient gave the pharmacist a prescription for Mirapex 0.125 mg TID #90. Which of the following is an appropriate generic substitution for Mirapex?
C. The generic name of Mirapex is pramipexole.
A patient gave the pharmacist a prescription for Comtan 200 mg 1 tablet by mouth with each dose of Sinemet #120. Which of the following is an appropriate generic substitution for Comtan?
C. The generic name of Comtan is entacapone.