Chapter 19: Parkinson’s Drugs

Question 1

Parkinsons disease

Answer 1

progressive degenerative disorder affects 1 million people making it the second only to Alzheimer’s as the most common degenerative disease of neurons. It develops in consequence of the break down or death of neurons in the brain. The loss of neurons causes the dopamine levels to drop and an imbalance of dopamine to acetylcholine.

Question 2

s/sx of parkinsons disease

Answer 2

stooped postre, masked face, back rigity, forward tilt of trunk, flexed elbows and wrists, tremors in the legs, reduced arm swing, hand tremor, slightly flexed hip and knees, shffling short steppped gait

Question 3

therpuetic goals of parkinsons disease

Answer 3

1. Drugs can only provide symptomatic relief, they do not cure PD!
2. Drug dose and selection are determined by the extent to which PD interferes with work, walking dressing, eating bathing, and other activities. Drugs benefit the patient primarily by improving bradykinesia, gait disturbance and postural instability.

Question 4

6 main classes of drgs that hae antiparkinsian activity

Answer 4

1. Dopamine replacement (levodopa/cardopa).
2. Dopamine agonists (Apomorphine, Pramipexole, Ropinirole, Rotigotine)
3. Monoamine oxidase type B (MAO B inhibitors) (Rasegiline, Selegiline)
4. COMT Inhibitors (Entacapone, Tolcapone)
5. Amantadine
6. Anticholenergics

Question 5

levodopa/cardopa

Answer 5

most effective agent for control of motor symptoms but also require the most frequent dosing. If a patient does not respond to Leva dopa/cardopa a PD diagnosis should be questioned. May take several months to develop full therapeutic results. MOA: Leva dopa crossed BBB and is taken up and converted to dopamine, it s active form. This helps restore the adequate balance of dopamine and acetylcholine. Cardopa blocks destruction of levodopa in the periphery and allows for the absorption of dopamine

1. Levodopa/Carbidopa (Sinemet)
   MOA: increases dopamine

Use: Is the most commonly prescribed and most effective drug for controlling the symptoms of Parkinson’s disease, particularly bradykinesia and rigidity.

SE: it is associated with risks of long-term side effects, such as involuntary movements (dyskinesia), restlessness, confusion, or abnormal movements.

Question 6

dopamine agonists

Answer 6

Also first line in the treatment of PD. MOA: Direct activation of Dopamine receptors

Question 7

MAO B inhibitors

Answer 7

Also first line treatment but the benefits are modest. Often combined with levodopa. MOA: inactivates dopamine deactivation. These drugs inhibit the deactivation of dopamine increasing it in the blood.

Question 8

COMT inhibitors

Answer 8

inhibits levadopa metabolism when given with levadopa.

Question 9

amanadine

Answer 9

Inhibits dopamine uptake

Question 10

Anticholinergics

Answer 10

MOA: Blocks muscarinic receptors thereby improving the balance of dopamine with acetylcholine. Used as a second line therapy for tremor. Often avoided in the elderly due to anticholenergic side effects.

Question 11

Oter tx options for parkinsons

Answer 11

If medications are not sufficiently effective, new, highly effective and safe surgical treatments are also available.

Question 12

prescribing considerations for levodopa/carbiddopa

Answer 12

• It is generally recommended that patients take levodopa/cardopa on an empty stomach, at least 30 minutes before, or one hour after meals.
• Monitor vital signs
• Evaluate the effects
• Minimize Side effects (watch drug type and dose).