Anti-emetics Flashcards
What are the four etiologies of N/V?
- Vestibular
- GI
- CTZ/VC
- CNS -etiology of vomiting from psyche disorders, AV, and cancer therapy
Where are the CTZ and VC located in the brain?
brainstem
Which receptors are located in the GI?
5-HT3 serotonin receptors
Which receptors are located in the ear/vestibular system?
H1 receptor/ Histamine
M1 receptor/Muscarinic
Which receptors are located in the CTZ zone? (4)
dopamine D2 receptors
NK-1 receptors
opioid receptors
5-HT3
What is simple N/V?
self limiting N/V that requires symptomatic therapy
patient complains of queasiness or discomfort
What is Complex N/V?
N/V that results in patient deterioration, fluid/electrolyte imbalances
patient complains of weight loss, fever, abdominal pain
Which labs should you monitor with a patient who suffers from N/V?
CMP- look at electrolytes
Upper/lower GI evaluation
What are the clinical uses of antacids?
simple N/V
ADE of antacids?
- Mg products cause diarrhea
- Al and calcium products cause constipation
- Sodium bicarbonate causes metabolic alkalosis
Ondansetron, Granisetron, Dolasetron (1st generation), and Palonosetron (2nd generation) are what class of drug?
5-HT3 antagonist
MOA of 5-HT3 antagonist?
block peripheral 5-HT3 receptors from intestinal vagal and spinal afferent nerves into the CTZ
What are clinical uses of 5-HT3 antagonist?
PONV
chemotherapy induced N/V
post radiation N/V
What is unique to Palonosetron?
- greater affinity to 5-HT3 receptor
- most potent
- half life around 40 hrs while 1st gen 5-HT3 have 1/2 life of 4-9 hrs
PK of 5-HT3 antagonist?
- extensive hepatic metabolism
- no need for dose reduction in those who have renal issues
- dose reduction with odansetron for those with hepatic issues
- slow colonic transit time
T/F 5-HT3 receptor antagonist have little effect on preventing delayed N/V ( i.e. 24 hrs after chemotherapy) when used alone
TRUE
T/F 5-HT3 are most effective if given 30 min (IV) before chemo administration
TRUE
Which drugs can be combined with 5-HT3 antagonist to enhance efficacy?
Corticosteroid/Dexamethasone
Olanzapine
NK1 receptor antagonist
What are most common ADE of 5-HT3 antagonist?
HA
constipation
QT prolongation with 1st generation drugs
Which of the 5-HT3 antagonist causes the greatest QT prolongation?
Dolasetron
What should you monitor with 5-HT3 antagonists?
hypomag, hypokalemia, bradyarrhythmia
Aprepitant and Fosaprepitant, Rolapitant are what drug class?
NK-1 receptor antagonist