Exam 2 Lecture 1 Flashcards
What is one of the most feared side effects induced by chemo
CNIV (Chemotherapy induced nausea and vomiting)
Complications that could result from CNIV
inability to deliver the intended full dose of chemotherapy.
could lead to dehydration, fatigue, depression, electrolyte abnormalities
What are some potential causes of nausea/vomiting in cancer patients
Therapy related- chemo, post surgical, radiation therapy
Gastrointestinal- constipation, gastroparesis, bowel obstruction
Neurologic- Severe chronic pain, anticipatory N/V,
Metabolic- hypercalcemia, hyperglycemia, hyponatremia
drugs- opioids, anesthetics
psychophysiologic- anxiety
what are the types of Nausea/vomiting? describe them
Anticipatory- learned response conditioned by severity and duration. can be provoked by sight, smell or sound
Acute- emetic response within 24 hrs of receiving chemotherapy
Delayed- related to chemotherapy occuring >24 hrs (probably due to substance P binding to neurokinin 1)
breakthrough- N/V occuring even if on scheduled anti-emetics prior to chemo
Refractory- N/V that persists despite appropriate anti-emetics
Why does nausea/vomiting happen during chemotherapy?
cytotoxic chemotherapy induces damage to the epithelial cells lining the GI tract.
Enterochromaffin cells lining the GI tract contain large stores of serotonin
These are released in massive quantities after exposure to chemo
Where in the brain is vomiting induced
The chemoreceptor trigger zone (CTZ) stimulates the vomiting center (Located in nucleus tractus solitarii in medulla)
What are the neurotransmitters implicated in CINV
Serotonin, Substance P (NK-1), dopamine, histamine, acetylcholine
Describe Serotonin and substance P role in CINV
serotonin- Plays a pivotal role in CINV in acute phase. Receptors are abundant in GI tract, area postrema and nucleus tractus solitari. There is an increased level of serotonin during exposure to chemotherapy. This is evidenced by the increase in serotonin metabolite 5-HIAA in urine after exposure to cisplatin.
Substance P- mammalian tachykinin found in neurons, including vagal afferent fibers innervating the brain-stem nucleus tractus solarii and area postrema. The biologic action of this neurokinin is mediated via NK-1
Describe the roles Dopamine, Histamine and acetylcholine play in CINV
Dopamine- D2 receptors are abundant in the area postrema of the medulla appears to mediate CINV. Primary sire of action is CTZ
Histamine- Histamine receptors are present in the nucleus tractus solitarii, efficacy of histamine antagonists is moderate. Useful when emesis is associated with motion
Acetylcholine- Muscarinic receptors are present near the CTZ, may have mild activity for motion associated n/v
What is the compound with the highest emetogenic chemotherapy potential
Cisplatin
How would level 1 and 2 agents contribute to emetogenicity of the regimen? What about adding level 3 and 4 agents?
Level 1 and 2 agents do not contribute to the emetogenicity of the regimen.
Adding level 3 or 4 agents increase emetogenicity by 1 level per agent
What are some risk factors for CINV
-Women>men
-Younger patients>old
-Prior h/o of motion sickness
-previous CINV tend to do worse
-anxiety/high pretreatment anticipation of nausea
- chronic alcoholism tends to be protective
Can we substitute different 5-HT3 antagonists for each other?
What are the 4 types of drugs used for prophylaxis of emesis
Yes.
NK-1 antagonist
Steroid
5-HT3 antagonist
Atypical antipsychotic
What are NK-1 antagonists drugs used for emetogenic prophylaxis
Aprepitant oral
Aprepitant Injectavle
Fosaprepitant
Rolapitant
Netupitant/palonsetron
Fosnetupretant/palnosetron
What are steroids used in steroids
Dexamethasone
What are the 5-HT3 antagonists used for prophylaxis in emesis
Dolasetron
Granisetron
Ondansetron
Palonsetron
WHat are atypical antispychotics used for prophylaxis in emesis
Olanzapine
What are the two classes of antiemetics that are always used regardless of what regimen we choose?
5HT3 antagonists
Steroid
Describe regimen A for prophylaxis of highly emetogenic susbatnces
NK-1 antagonists
Steroid
5-HT3 antagonist
Atypical antipsychotic
Describe regimen B for prophylaxis of HIGHLY emetogenic substance
Atypical antipsychotic
5-HT3 antagonist
Steroid
Describe regimen C for prophylaxis of highly emetogenic substance
NK-1 antagonist
Steroid
5 HT3 antagonist
Describe regimen A of moderately emetogenic substances
Steroid
5 HT3 antagonist
Describe regimen B of moderately emetogenic substances
Olanzapine
Palonsetron
Dexamethasone
Describe regimen C of moderately emetogenic substances
NK-1 antagonist
steroid
5 HT3 antagonist