Emesis is the forceful expulsion of gastric contents from the body and includes nausea and vomiting. Vomiting is triggered by impulses in the vomiting center of the medulla that lead to coordinated muscle contractions. Treatment depends on the underlying cause but commonly includes antacids, antihistamines, phenothiazines, corticosteroids, metoclopramide, cannabinoids, and serotonin receptor antagonists either alone or in combination. For chemotherapy-induced nausea and vomiting, guidelines recommend combination regimens containing multiple classes of antiemetics.
2. Nausea
Defined as the inclination to vomit
or as a feeling in the throat or
epigastric region alerting an
individual that vomiting is
imminent.
Vomiting
The ejection or expulsion of gastric
contents through the mouth, often
requiring a forceful event .
3. Pathophysiology
Vomiting is triggered by afferent impulses to the vomiting
center a nucleus of cells in the medulla. Impulses are
received from sensory center such as the chemoreceptor
trigger zone (CTZ),Cerebral cortex ,and visceral afferent
from the pharynx and GIT.
When excited, afferent impulses are integrated by the
vomiting center, resulting in efferent impulses to the
salivation center, respiratory center, and the pharyngeal, GI,
and abdominal muscle, leading to vomiting.
The CTZ located in the area postrema of the fourth ventricle
of the brain is a major chemosensory organ the emesis and is
usually associated with chemically induced vomiting.
4.
5. Treatment
Treatment option for the nausea and vomiting include drug and nondrug
modalities.
Treatment depend on associated medical condition.
For patient with simple complaints, perhaps to food or beverages
consumption avoidance or moderation of dietary intake may be preferable.
Nonpharmacological intervention classified as behavioral intervention and
include relaxation ,biofeedback,self-hupnosis , cognitive distraction ,guided
imagery and systemic desensitization.
Psychogenic vomiting may benefit from psychological intervention.
6. Pharmacological management
For most conditions, a single agent antiemetic is preferred. If patient not
responding to such therapy and those receiving highly emetogenic
chemotherapy, multiple agent regimens are required.
Simple nausea and vomiting is treated with both nonprescription and
prescription drugs in small doses.
Management of complex nausea and vomiting in patient receiving cytotoxic
chemotherapy may require combination therapy.
9. Drug classification
1. Antacids
Agent Use in single and combination nonprescription antacids
products, especially those containing Mg hydroxide, Al hydroxide and
Ca carbonate provide sufficient relief from simple nausea and
vomiting through gastric acid neutralization
It include one or more small doses of single or multiple product.
2. Histamine-2 Receptor Antagonists
Histamine-2 antagonist(cimetidine, famotidine, nizatidine, ranitidine)
may be used in low doses to manage simple nausea and vomiting
associated with heartburn or gastroesophageal reflux.
10. Classification of drugs
3. Antihistamine-anticholinergic Drugs
These may be appropriate in the treatment of simple symptomatology.
ADRs these shows are include drowsiness and confusion, dry mouth tachycardia
etc.
4. Phenothiazines
Are most useful in patient with simple nausea and vomiting
Rectal administration may be use for patients where oral and parenteral
administration is not feasible
Example include Compazine , Prolixin, serentil
11. Drug classification
4. Corticosteroids
Dexamethasone mostly use in nausea and vomiting of chemotherapy induced and postoperative nausea and vomiting single or in combination with SSRIs
Dexamethasone is effective in prevention of both cisplatin-induced acute emesis and when alone or in combination for the prevention of delayed nausea and
vomiting associated with chemotherapy induced NV .
5. Metoclopramide
Metoclopramide increases lower esophageal sphincter tone, aids gastric emptying and accelerate transit through small bowel possibly the release
of acetylcholine.
It is used for its antiemetic properties in patient with diabetic gastroparesis and with dexamethasone for prophylaxis of delayed nausea and
vomiting associated with chemotherapy administration.
7. Cannabinoids
Oral nabilone and oral dronabinol were slightly more effective comparative in patient receiving
moderately emetogenic chemotherapy reigemens.
12. Drug classification
8. Substance P/ Neurokinin 1 receptor Antagonists
Aprepitant is first approved member of this class and indicated as multiple drug
regimen for prophylaxis of nausea and vomiting associated with high dose
cisplatin based chemotherapy
9. SSRIs
Ondansetron and dolasetron act by blocking presynaptic serotonin receptor on
sensory vagal fibers in the gut wall
ADRs common are constipation, headache
13. Chemotherapy induced nausea and
vomiting
Nausea and vomiting that occur within 24 hours of chemotherapy administration
is defined as acute whereas when it starts more than 24 hours after
chemotherapy administration defined as delayed.
14. Prophylaxis of chemotherapy induced
Nausea and vomiting
Patient receiving chemotherapy that is classified as being of high emetic risk
should receive a combination antiemetic regimen containing three on the day
of chemotherapy administration (day1) an SSRI plus dexamethasone plus
aprepitant.
Patient receiving regimens that are classified as being of moderate emetic
risk should receive a combination antiemetic regimen containing an SSRIs plus
dexamethasone on day 1.
Dexamethasone alone is recommended for prophylaxis prior to regimens of
low emetic risk.
15.
16.
17. Treatment for CINV
Chlorpromazine, prochlorperazine, promethazine, methylprednisolone,
lorazepam, metoclopramide, dexamethasone or dronabinol used for adult
patient.
The choice of specific agent should based on patient specific factor including
potential for ADRs and cost.
Aprepitant, dexamethasone, or metoclopramide have demonstrated efficacy
in preventing CINV.
Aprepitant and dexamethasone are used on day 2 after administration of high
risk emetic chemotherapy.
19. Radiation induced Nausea and Vomiting
Patient receiving single exposure, high dose radiation therapy to the upper
abdomen or total or semi body radiation should receive prophylactic
antiemetic. Preventive therapy with an SSRIs and dexamethasone is
recommended in patient receiving total body irradiation.
20. Antiemetic use during pregnancy
Life style modification and dietary modification
Pyridoxine 10 to 25 mg 4 time is first line therapy if symptoms persist
addition of a histamine-1 receptor antagonist such as dimenhydrinate,
diphenhydramine, or meclizine, is recommended.
21. Antiemetic use in children
Children receiving chemotherapy of high or moderate risk a corticosteroid
plus SSRIs should use.
For Nausea and Vomiting associated with pediatric gastroenteritis there is
greater emphasis on rehydration measures than on pharmacologic
intervention.
