Sherpath: Drugs Used In The Management Of Specific Neurodegenerative Disorders

Dopaminergics include

Carbidopa-levodopa

Enteral Suspension Carbidopa-Levodopa

2000 mg/day over 16 hours

Baseline data needed before Carbidopa-Levodopa administration

Vital signs Laboratory tests: Complete blood count (CBC), liver function test (LFT), prolactin level, pregnancy test Symptoms: Current motor symptoms and any impairment to ADLs

Catechol-o-methyl transferase (COMT) Inhibitors include

Entacapone, tolcapone

Match the class of drugs used to treat Parkinson's disease with its mechanism of action. A. Affect dopamine content of the brain B. Stimulate dopamine receptors of nerve cells in the brain C. Inhibit activity of acetylcholine D. Inhibit activity of monoamine oxidase (MAO)

A. Dopaminergics B. Dopamine agonists C. Anticholinergics D. MAO-B inhibitors

Dopamine Agonists

Act directly on the dopamine receptors of nerve cells in the brain by stimulating them. Exact mechanism of action is not understood.

Side Effects and Adverse Effects of Rivastigmine RESP

Adverse effects: ***Life threatening: Respiratory depression with overdose

Side Effects and Adverse Effects of Carbidopa-Levodopa HEMA

Adverse effects: **Life threatening: Thrombocytopenia, hemolytic anemia, agranulocytosis**

Dopaminergics

Affect the dopamine content of the brain. Levodopa is converted into dopamine by nerve cells in the brain. When combined with carbidopa, more levodopa is permitted to reach the brain and a lower dose is required.

Dopamine Agonists include

Amantadine, bromocriptine, pramipexole, ropinirole HCl

Through which route is carbidopa-levodopa excreted? A. Liver B. Urine C. Bile D. Saliva

B. Urine

Catechol-o-methyl transferase (COMT) Inhibitors

Block COMT, an enzyme that breaks down dopamine, and prolongs the effect of levodopa. With a higher concentration in the brain, a lower dose of levodopa is required.

Laboratory Tests for Carbidopa-Levodopa

Blood urea nitrogen (BUN), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) levels could show an increase.

Which statement correctly explains the action of rivastigmine? A. Interferes with the breakdown of dopamine B. Breaks down acetylcholine in the neuron receptors C. Increases availability of acetylcholine in the neuron receptors D. Reverses clinical manifestations of Alzheimer's disease

C. Increases availability of acetylcholine in the neuron receptors

Which route of administration for rivastigmine results in a peak concentration between 8 and 16 hours? A. Oral B. Intravenous C. Transdermal D. Subcutaneous

C. Transdermal

Drug and Food interactions with Carbidopa-Levodopa

Drug: Anticholinergics and antipsychotics may reduce the effect of levodopa. Tricyclic antidepressants (TCAs) may cause dyskinesia and hypertension. Methyldopa may cause psychosis. MAO inhibitors can result in severe hypertension. MAO inhibitors may trigger melanoma; monitor skin for changes. Patients with heart disease or mental disorders or those on MAO-B inhibitor therapy should use with caution. Food: Foods high in protein may reduce levodopa absorption from the intestine.

Patient teaching: side effects of Rivastigmine

Common: Nausea, vomiting, diarrhea, anorexia, abdominal pain, and weight loss ***Report immediately: Severe nausea/vomiting, increased salivation, diaphoresis, bradycardia, hypotension, respiratory depression, and seizures Teach patients to rise slowly to avoid orthostatic hypotension. Explain to patients the importance of regular liver tests because hepatotoxicity can occur.

Contraindications and cautions with rivastigmine

Contraindications: History of reactions to rivastigmine at application site; hypersensitivity to drugs with similar compounds (carbamate derivatives) Cautions: Liver/renal disease Simultaneous nonsteroidal antiinflammatory drug (NSAID) use Peptic ulcers Urinary obstruction Sick sinus syndrome, bradycardia, or supraventricular defects COPD, asthma Patients under 50 kg (110 lb) Seizure disorders Urinary retention

Contraindications and Interactions with Carbidopa-Levodopa

Contraindications: Glaucoma, malignant melanoma Cautions: History of myocardial infarction (MI), dysrhythmias, asthma, emphysema, renal/hepatic impairment, pulmonary impairment, seizure disorder, peptic ulcer disease, depression

Which statement explains the action of carbidopa-levodopa? A. Carbidopa decreases symptoms of parkinsonism. B. Carbidopa inhibits the breakdown of dopamine at the synapses in the brain. C. Carbidopa inhibits the catechol-o-methyltransferase (COMT) enzyme, increasing the concentration of levodopa. D. Carbidopa prevents levodopa decarboxylation in the periphery, resulting in more levodopa being transported to the brain.

D. Carbidopa prevents levodopa decarboxylation in the periphery, resulting in more levodopa being transported to the brain.

Drug and Herb interactions with rivastigmine

Drug: Effects of theophylline and general anesthetics are increased. TCAs decrease effects of rivastigmine. Cimetidine increases effects of rivastigmine. NSAIDs increase GI effects. Tobacco increases rivastigmine clearance. Herb: Cholinergic effects may be increased with gingko biloba.

Side effects of Carbidopa-Levodopa to tell pts about

Inform patients that discolored urine or dark perspiration may occur. Instruct patients that dyskinesia (involuntary muscle movement) should be reported. Teach patients that side effects may include GI disturbances, orthostatic hypotension, and mental disturbances.

Diet on Carbidopa-Levodopa

Inform patients that if GI problems occur, they can take the medication with food; patients should be aware that this will decrease the rate of absorption. Inform patients taking selegiline that eating foods high in tyramine (red wine, yogurt, bananas, and aged cheese) can result in a hypertensive crisis. Advise patients to eat a low-protein diet because protein can interfere with the drug reaching the brain, thus decreasing effectiveness.

General Patient Teaching for Rivastigmine

Inform patients that rivastigmine may improve symptoms but will not stop the disease progression. Take the medication with meals. Swallow whole; do not chew. Ensure patients or care providers are aware of when medication is due and when the dose should be increased. Explain safety techniques (keeping paths clear to avoid injury when a patient may wander). Inform family members that there are support groups available to them, such as the Alzheimer's Disease and Related Disorders Association. Notify family members about specific foods to prepare that may help with consumption and tolerance during this therapy.

Anticholinergics;Antiparkinsonian agents

Inhibit or reduce the activity of acetylcholine. Acetylcholine is balanced by dopamine and becomes excessive when dopamine is depleted; this contributes to the motor symptoms seen with parkinsonism.

Monoamine oxidase (MAO)-B Inhibitors

Inhibit the actions of monoamine oxidase, which is an enzyme that breaks down dopamine. With this enzyme stopped, dopamine is available to be reabsorbed by neurons and saved for later use.

Lab tests when on rivastigmine

May result in higher levels of ALT and AST

Immediate Release

PO: three to four times a day No more than eight tablets or 80 mg carbidopa/800 mg levodopa (80/800 mg) per day Initial dose: One tablet of 10 or 25 mg carbidopa/100 mg levodopa Maintenance: 25/250 mg

Extended-Release Capsules Carbidopa-Levodopa

PO: two times a day No more than 1600 mg/day Initial dose: 50 mg carbidopa/200 mg levodopa

Medical hx to note with rivastigmine

Renal or liver disease, peptic ulcer, chronic obstructive pulmonary disease (COPD), asthma, or urinary obstruction

Monoamine oxidase (MAO)-B Inhibitors include

Selegiline HCl, rasagiline

Side Effects and Adverse Effects of Rivastigmine CV

Side effects: Bradycardia, hypotension with overdose Adverse effects: ***Life threatening: MI, heart failure

Side Effects and Adverse Effects of Rivastigmine INTEG

Side effects: Diaphoresis with overdose Adverse effects: ***Life threatening: Stevens-Johnson syndrome

Side Effects and Adverse Effects of Rivastigmine CNS

Side effects: Dizziness, headache, insomnia Adverse effects: ***Life threatening:*** Suicidal ideation, Seizures

Side Effects and Adverse Effects of Carbidopa-Levodopa CNS

Side effects: Involuntary movements of face, tongue, arms, and upper body; depression; anxiety Adverse effects: Involuntary movements, psychosis, depression with suicidal tendencies

Side Effects and Adverse Effects of Carbidopa-Levodopa GI

Side effects: Nausea, vomiting, anorexia, dry mouth, flatulence Adverse effects: Urinary retention

Side Effects and Adverse Effects of Rivastigmine GI/GU

Side effects: Nausea, vomiting, diarrhea, abdominal pain, anorexia, dyspepsia Adverse effects: ***Life threatening: HepatotoxicityIncreased salivation, severe nausea/vomiting with overdose

Side Effects and Adverse Effects of Carbidopa-Levodopa CV

Side effects: Orthostatic hypotension Adverse effects: Palpitations **Life threatening: Cardiac dysrhythmias

acetylcholinesterase (AChE) (or cholinesterase) inhibitors MOA

Stops the breakdown of acetylcholine, allowing more to be available to the neuron receptors

General teaching for pts taking Carbidopa-Levodopa

Teach patients that if the medication is stopped abruptly, an increase in parkinsonism symptoms may occur. Inform patients that symptoms may persist for weeks or months before a therapeutic goal is reached and they are controlled. Warn patients that extended-release tablets should not be crushed or chewed.

Anticholinergics;Antiparkinsonian agents include

Trihexyphenidyl, benztropine, biperiden

acetylcholinesterase (AChE) (or cholinesterase) inhibitors are used to treat

alzheimer's disease

acetylcholinesterase (AChE) (or cholinesterase) inhibitors include

rivastigmine, tacrine, and donepezil