Question 1

A patient with Parkinson disease is taking levodopa/carbidopa [Sinemet]. The prescriber orders bromocriptine [Parlodel] to treat dyskinesias. The nurse notes that the patient is agitated, and the patient reports having frequent nightmares. The nurse will contact the provider to discuss:

Accepted Answer

Bromocriptine is used to treat levodopa-induced dyskinesias and has dose-dependent psychologic side effects. The nurse should suggest reducing the dose of this drug to minimize these side effects. Adding an antipsychotic medication is not indicated. Cabergoline is not approved for this use. Reducing the dose of levodopa/carbidopa is not indicated.

Question 2

A nursing student wants to know why a patient who has been taking levodopa [Dopar] for years will now receive levodopa/carbidopa [Sinemet]. The nurse explains the reasons that levodopa as a single agent is no longer available. Which statement by the student indicates a need for further education?

Accepted Answer

Adding carbidopa to levodopa does not reduce the incidence of dyskinesias or psychosis. In fact, carbidopa can increase the intensity and the speed of onset of these effects. Carbidopa inhibits decarboxylation of levodopa in the intestine and peripheral tissues, leading to more levodopa in the CNS. Carbidopa cannot cross the blood-brain barrier, so it does not have this action in the CNS. Peripheral side effects are reduced, including nausea, vomiting, and cardiovascular effects.

Question 3

The nurse provides teaching for a patient who will begin taking rotigotine [Neupro] to treat Parkinson disease. What will the nurse include in teaching?

Accepted Answer

Rotigotine is a nonergot dopamine agonist, which is given by starting with a 2-mg dose that is increased by 2 mg each week until the lowest effective dose is reached. It should not be stopped abruptly but should be decreased by 2 mg per week until tapered off. It undergoes extensive first-pass metabolism, so it is not given orally and is currently available as a transdermal patch.

Question 4

A nurse provides teaching for a patient who is newly diagnosed with Parkinson disease. Which statement by the patient indicates understanding of the drug therapy for this disease?

Accepted Answer

Levodopa combined with carbidopa is the initial drug of choice to treat motor symptoms. Amantadine is the only drug recommended to treat dyskinesias. Entacapone and rasagiline are used to treat abrupt loss of effect, or "off" times. Drug therapy does not slow the progression of the disease.

Question 5

A patient has been diagnosed with Parkinson disease (PD) and begins treatment with levodopa/carbidopa [Sinemet]. After several months of therapy, the patient reports no change in symptoms. The nurse will expect the provider to:

Accepted Answer

Patients beginning therapy with levodopa/carbidopa should expect therapeutic effects to occur after several months of treatment. Levodopa is so effective that a diagnosis of PD should be questioned if the patient fails to respond in this time frame. Adding a dopamine agonist is not indicated. The "on-off" phenomenon occurs when therapeutic effects are present. Increasing the dose of levodopa/carbidopa is not indicated.

Question 6

A hospitalized patient with Parkinson disease who is receiving apomorphine to treat "off" episodes develops nausea and vomiting. The nurse will discuss the use of which medication with the patient's provider?

Accepted Answer

Trimethobenzamide can be used as an antiemetic in patients treated with apomorphine. Serotonin receptor agonists (eg, ondansetron) and dopamine receptor antagonists (eg, prochlorperazine) cannot be used, because they increase the risk of serious postural hypotension. Levodopa only increases nausea and vomiting.

Question 7

A patient has taken levodopa [Dopar] for Parkinson disease for 2 weeks but reports no improvement in the symptoms. Which response by the nurse is correct?

Accepted Answer

A full therapeutic response with levodopa may take several months to develop. Until the True effect of the dose is seen, it is not necessary to change to another drug, increase the dose, or change the drug regimen.

Question 8

A nursing student wants to know how carbidopa can be effective for treating Parkinson disease if it prevents the conversion of levodopa to dopamine. The nurse explains that carbidopa:

Accepted Answer

Carbidopa inhibits decarboxylation of levodopa in the intestine and peripheral tissues, leading to more levodopa in the CNS. Carbidopa cannot cross the blood-brain barrier, so it does not have this action in the CNS. Carbidopa is not given with high-protein meals. Carbidopa does not have dopamine-like effects. Carbidopa does not affect abrupt loss of effect.

Question 9

A patient who has begun taking levodopa/carbidopa [Sinemet] reports feeling lightheaded and dizzy, especially when standing up from a sitting position. What will the nurse recommend?

Accepted Answer

Postural hypotension is common early in treatment and can be reduced by increasing the intake of salt and water. An alpha-adrenergic agonist, not an antagonist, can help. Amantadine is used to treat levodopa-induced dyskinesias. Drug holidays are used when adverse effects increase with long-term use of levodopa; the drug holiday allows beneficial effects to be achieved with lower doses, which reduces the incidence of side effects.

Question 10

A patient with Parkinson disease is taking levodopa/carbidopa [Sinemet] along with amantadine [Symmetrel] 400 mg/day to treat dyskinesias. The patient reports having increased dyskinesias several months after beginning the amantadine. The nurse will contact the provider to discuss which action?

Accepted Answer

When amantadine is added to therapy to treat dyskinesias associated with levodopa, it often loses effectiveness after several months. If the effects diminish, they can be restored by either increasing the dosage or by interrupting treatment for several weeks. The maximum dosage of amantadine is 400 mg/day, so it is incorrect to increase the dose. Altered renal function would result in drug toxicity, not ineffectiveness of the drug. It is not necessary to order another drug until determining whether the effectiveness can be restored.

Question 11

A patient who is newly diagnosed with Parkinson disease is prescribed levodopa [Dopar]. The patient asks the nurse about drugs to prevent disease progression. What will the nurse tell this patient?

Accepted Answer

To date, there is no definitive proof that any drug can protect dopaminergic neurons from progressive degeneration. Levodopa has shown neuroprotective effects, but studies have demonstrated toxic effects in the doses required for this purpose. MAO-B inhibitors have shown benefits, but only in animal studies. Vitamin E was once theorized to offer this protection, but recent studies have provided good evidence that this is not the case.

Question 12

A nurse is discussing motor symptoms with a patient with Parkinson disease who has been taking levodopa/carbidopa [Sinemet] for 9 months and who is now having regular tics. Which statement by the patient indicates understanding of this symptom?

Accepted Answer

Levodopa can cause movement disorders, generally within the first year of therapy. If they occur, a lower dose of levodopa may be required to alleviate them. Clozapine is an antipsychotic used to treat levodopa-induced psychoses. Movement disorders generally occur as the dose of levodopa increases. Surgery is a last option for treating movement disorders, after amantadine fails.

Question 13

A patient newly diagnosed with Parkinson disease has been taking levodopa/carbidopa [Sinemet] for several weeks and complains of nausea and vomiting. The nurse tells the patient to discuss what with the provider?

Accepted Answer

Because levodopa activates the chemoreceptive trigger zone (CTZ) of the medulla, causing nausea and vomiting (N/V), the patient may need to take a lower dose temporarily until tolerance develops. A meal helps slow absorption to minimize this side effect. A high protein intake contributes to abrupt loss of effect, so meals should be low in protein. Taking a dose on an empty stomach increases absorption and also N/V. An increased dose with a high-protein snack increases N/V and also abrupt loss of effect. Dopamine increases N/V, because it activates the CTZ of the medulla.

Question 14

A nurse is teaching a group of nurses about Parkinson medications. The nurse is correct to state that one side effect associated with pramipexole [Mirapex] that is less likely to occur with other dopamine agonists is:

Accepted Answer

A few patients taking pramipexole have experienced sleep attacks, or an overwhelming and irresistible sleepiness that comes on without warning. Dizziness, hallucinations, and dyskinesias are listed as side effects of pramipexole and other dopamine agonists.

Question 15

A patient with Parkinson disease is taking levodopa/carbidopa [Sinemet] and reports occasional periods of loss of drug effect lasting from minutes to several hours. The nurse questions the patient further and discovers that these episodes occur at different times related to the medication administration. The nurse will contact the provider to discuss:

Accepted Answer

This patient is describing abrupt loss of effect, or the "off" phenomenon, which is treated with entacapone or another COMT inhibitor. Amantadine is used to treat dyskinesias. A direct-acting dopamine agonist is useful for gradual loss of effect, which occurs at the end of the dosing interval as the dose is wearing off. Shortening the dosing interval does not help with abrupt loss of effect.

Quiz 21: Drugs for Parkinson Disease