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
