Chpt 15 Antiparkinson Drugs Pharmacology

A patient taking entacapone (Comtan) for the first time calls the clinic to report a dark discoloration of his urine. After listening to the patient, the nurse realizes that what is happening in this situation? a. This is a harmless effect of the drug. b. The patient has taken this drug along with red wine or cheese. c. The patient is having an allergic reaction to the drug. d. The ordered dose is too high for this patient.

A COMT inhibitors, including entacapone, may darken a patient's urine and sweat.

Which drug used for the management of the patient with PD is most likely to cause postural hypotension? a. amantadine (Symmetrel) b. selegiline (Eldepryl) c. tolcapone (Tasmar) d. entacapone (Comtan)

A Rationale: Amantadine, carbidopa-levodopa, and ropinirole are most likely to cause postural hypotension.

The patient diagnosed with PD has been started on dopaminergic replacement drug therapy with carbidopa-levodopa, it is most important for the nurse to a. assess the patient for dizziness and syncope when the patient is walking. b. administer the medication first thing in the morning. c. administer the medication on an empty stomach. d. omit protein from the patient's diet.

A Rationale: The patient may need assistance when walking because of the dizziness and possible syncope caused by these drugs. Doses are given several hours before bedtime to decrease the incidence of insomnia, a known adverse effect of these drugs. Oral doses are given with food to help minimize GI upset. It is important to make sure that the patient and family or caregivers understand that while taking carbidopa-levodopa, the patient may continue to eat high-protein foods (e.g., meat, fish, poultry, and dairy products) but with the following special instructions: use portion control (meat portion about the size of a deck of cards) and take the drug dose one-half hour before eating a protein-containing meal or one hour after.

hen assessing the medication history of a patient with a new diagnosis of Parkinson's disease, which conditions are contraindications for the patient who will be taking carbidopa-levodopa? (Select all that apply.) a. Angle-closure glaucoma b. History of malignant melanoma c. Hypertension d. Benign prostatic hyperplasia e. Concurrent use of monoamine oxidase inhibitors (MAOIs)

A, B, E Angle-closure glaucoma, a history of melanoma or other undiagnosed skin conditions, and concurrent use of MAOIs are contraindications to the use of carbidopa-levodopa. The other options are incorrect.

A patient has been taking selegiline (Eldepryl), 20 mg/day for 1 month. Today, during his office visit, he tells the nurse that he forgot and had a beer with dinner last evening, and "felt awful." What did the patient most likely experience? a. Hypotension b. Hypertension c. Urinary discomfort d. Gastrointestinal upset

B At doses that exceed 10 mg/day, selegiline becomes a nonselective monoamine oxidase inhibitor (MAOI), contributing to the development of the cheese effect, so-called because it interacts with tyramine-containing foods (cheese, red wine, beer, and yogurt) and can cause severe hypertension.

While a patient is receiving drug therapy for Parkinson's disease, the nurse monitors for dyskinesia, which is manifested by which finding? a. Rigid, tense muscles b. Difficulty in performing voluntary movements c. Limp extremities with weak muscle tone d. Confusion and altered mental status

B Dyskinesia is the difficulty in performing voluntary movements that is experienced by some patients with Parkinson's disease. The other options are incorrect.

The nurse is developing a care plan for a patient who is taking an anticholinergic drug. Which nursing diagnosis would be appropriate for this patient? a. Diarrhea b. Urinary retention c. Risk for infection d. Disturbed sleep pattern

B Patients receiving anticholinergic drugs are at risk for urinary retention and constipation, not diarrhea. The other nursing diagnoses are not applicable to anticholinergic drugs.

A patient has been diagnosed with PD. Medication therapy is started for this patient. The nurse should teaching the patient and care giver that pharmacologic therapy of PD? A. The medication should be stopped when the patient's symptoms improve. B. Alcohol, over-the-counter drugs, and herbals are to be avoided unless approved by the prescriber. C. A common side effect of anticholinergics is drooling. D. Improvements in symptoms are expected within 5 days of medication therapy.

B Rationale: Alcohol, over-the-counter drugs, and herbals are to be avoided unless approved by the prescriber. Emphasize the importance of taking the medication as prescribed and not quitting the medication. It is important for the patient and family or caregiver to understand that medication(s) must be taken at the dosage and time prescribed. Inability to adhere to or remain compliant may lead to exacerbation of symptoms and development of complications. Missing a dose by even 30 minutes may lead to an "off" period and last hours. With anticholinergics, warn the patient about the adverse effect of dry mouth. Use of artificial saliva drops or gum, frequent mouth care, fluids, and sucking on sugarless gum or hard candy may be helpful. The patient and family must understand that some antiparkinson drugs are often titrated to the patient's response and that it may take 3 to 4 weeks for a therapeutic response to become evident.

The "off-on phenomenon" that some patients with PD experience is best explained as the a. need to take a drug holiday to improve response to medications. b. variable response to levodopa, resulting in periods of good control and periods of poor control of PD symptoms. c. alternating schedule of medications needed to control PD. d. fluctuation of emotions that often occurs with PD.

B Rationale: Some patients who take levodopa on a long-term basis experience times when their PD symptoms are under control and other times when symptoms are not well controlled.

A patient has been given a prescription for levodopa-carbidopa (Sinemet) for her newly diagnosed Parkinson's disease. She asks the nurse, "Why are there two drugs in this pill?" The nurse's best response reflects which fact? a. Carbidopa allows for larger doses of levodopa to be given. b. Carbidopa prevents the breakdown of levodopa in the periphery. c. There are concerns about drug-food interactions with levodopa therapy that do not exist with the combination therapy. d. Carbidopa is the biologic precursor of dopamine and can penetrate into the central nervous system.

B When given in combination with levodopa, carbidopa inhibits the breakdown of levodopa in the periphery and thus allows smaller doses of levodopa to be used. Lesser amounts of levodopa result in fewer unwanted adverse effects. Levodopa, not carbidopa, is the biologic precursor of dopamine and can penetrate into the CNS.

When treating patients with medications for Parkinson's disease, the nurse knows that the wearing-off phenomenon occurs for which reason? a. There are rapid swings in the patient's response to levodopa. b. The patient cannot tolerate the medications at times. c. The medications begin to lose effectiveness against Parkinson's disease. d. The patient's liver is no longer able to metabolize the drug.

C The wearing-off phenomenon occurs when antiparkinson medications begin to lose their effectiveness, despite maximal dosing, as the disease progresses. The other options are incorrect.

The nurse is assessing the medication history of a patient with a new diagnosis of Parkinson's disease. Which condition is a contraindication for the patient, who will be taking tolcapone (Tasmar)? a. Glaucoma b. Seizure disorder c. Liver failure d. Benign prostatic hyperplasia

C Tolcapone is contraindicated in patients who have shown a hypersensitivity reaction to it, and it should be used with caution in patients with pre-existing liver disease. The other conditions listed are not contraindications.

A patient has a new order for a catechol ortho-methyltransferase (COMT) inhibitor as part of treatment for Parkinson's disease. The nurse recognizes that which of these is an advantage of this drug class? a. It has a shorter duration of action. b. It causes less gastrointestinal distress. c. It has a slower onset than traditional Parkinson's disease drugs. d. It is associated with fewer wearing-off effects.

D COMT inhibitors are associated with fewer wearing-off effects and have prolonged therapeutic benefits. They have a quicker onset, and they prolong the duration of action of levodopa.

Carbidopa-levodopa (Sinemet) is prescribed for a patient with Parkinson's disease. The nurse informs the patient that which common adverse effects can occur with this medication? a. Drowsiness, headache, weight loss b. Dizziness, insomnia, nausea c. Peripheral edema, fatigue, syncope d. Heart palpitations, hypotension, urinary retention

D Common adverse reactions associated with carbidopa-levodopa include palpitations, hypotension, urinary retention, dyskinesia, and depression. The other effects may occur with other antiparkinson drugs.

When a patient is taking an anticholinergic such as benztropine (Cogentin) as part of the treatment for Parkinson's disease, the nurse should include which information in the teaching plan? a. Minimize the amount of fluid taken while on this drug. b. Discontinue the medication if adverse effects occur. c. Take the medication on an empty stomach to enhance absorption. d. Use artificial saliva, sugarless gum, or hard candy to counteract dry mouth.

D Dry mouth can be managed with artificial saliva through drops or gum, frequent mouth care, forced fluids, and sucking on sugar-free hard candy. Anticholinergics should be taken with or after meals to minimize GI upset and must not be discontinued suddenly. The patient must drink at least 3000 mL/day unless contraindicated. Drinking water is important, even if the patient is not thirsty or in need of hydration, to prevent and manage the adverse effect of constipation.

The patient has now been ordered an oral disintegrating form of the MAO-B inhibitor drug selegiline. When administering the drug, the nurse should A. tell the patient to take the medication with liquids. B. tell the patient to take the medication with a meal. C. assess the patient for hypertension, a common side effect of this medication. D. tell the patient to place oral disintegrating dosage forms on the tongue, and do not swallow dosage form until it is completely melted.

D Rationale: The oral disintegrating dose should be placed on the tongue and should not be swallowed until it is completely melted. This dosage form is to be taken without liquids and given in the morning before breakfast. Foods and fluids are not to be consumed for 5 minutes before or after the drug is taken. Postural hypotension may be a transient problem, so the patient needs to move and change positions slowly and purposely.

When providing teaching to a patient receiving an anticholinergic for the treatment of PD, the nurse will include which information? a. Take the medication first thing in the morning. b. Limit fluid intake when taking this drug. c. The tremors you experience will be reduced within 24 hours of taking this drug. d. Do not take this medication at the same time as other medications.

D Rationale: When anticholinergics are used for the treatment of PD, these medications should not be taken at the same time as other mediations. The medications should be administered at bedtime. Fluid intake should not be restricted as they cause dry mouth, and it may take several days to weeks for the beneficial effects of the medication to become evident.

A patient has been treated with antiparkinson medications for 3 months. What therapeutic responses should the nurse look for when assessing this patient? a. Decreased appetite b. Gradual development of cogwheel rigidity c. Newly developed dyskinesias d. Improved ability to perform activities of daily living

D Therapeutic responses to antiparkinson agents include an improved sense of well-being, improved mental status, increased appetite, increased ability to perform activities of daily living and to concentrate and think clearly, and less intense parkinsonian manifestations.