Chemotherpy of nausea and emesis
Nausea is usually defined as the inclination to vomit or as a feeling in the throat or epigastric region alerting an individual that vomiting is imminent.
Vomiting is defined as the ejection or expulsion of gastric contents..................
presented by
V.Wazeed Pharm-D
2. DEFINITION
Nausea is usually defined as the inclination to vomit or as a feeling in
the throat or epigastric region alerting an individual that vomiting is
imminent.
Vomiting is defined as the ejection or expulsion of gastric contents
through the mouth and is often a forceful event.
the stomach itself does not actively expel its contents during vomiting.
The stomach, oesophagus, and their relevant sphincters are all in fact
relaxed during vomiting. Most of the force that expels the contents
arises from the contraction of the diaphragm
3. CAUSES
• Motion sickness or seasickness
• Early stages of pregnancy
• Medication-induced vomiting
• Intense pain
• Emotional stress (such as fear)
• Gallbladder disease
• Food poisoning
• Infections (such as the "stomach
flu")
• Overeating
• A reaction to certain smells or
odors
• Heart attack
• brain injury
• Brain tumor
• Ulcers
• psychological illnesses
• slow stomach emptying (a
condition that can be seen in
people with diabetes)
• Ingestion of toxins or excessive
amounts of alcohol
• Bowel obstruction
• Appendicitis
4. SYMPTOMS OF THE NAUSEA AND VOMITING
abdominal pain
diarrhea
fever
lightheadedness
vertigo
rapid pulse
excessive sweating
dry mouth
decreased urination
chest pain
fainting
confusion
vomiting blood
5. COMPLICATIONS
Severe vomiting can lead to symptomatic dehydration and electrolyte
abnormalities (typically a metabolic alkalosis with hypokalemia) or rarely to an
esophageal tear, either partial or complete. Chronic vomiting can result in
undernutrition, weight loss, and metabolic abnormalities.
PATHOPHYSIOLOGY
Nausea and vomiting involves the stimulation of the VC in the medulla by one
or more of the following pathways and is mediated by varying
neurotransmitters:
Peripheral Pathways
a. Nausea triggered by mechanoreceptors and chemoreceptors in the GI tract,
serosa, and viscera transmitted via the vagus and splanchnic nerves,
sympathetic ganglia, and glossopharyngeal nerves to the Chemoreceptor
Trigger Zone (CTZ) and VC.
6. Vestibular System
a. Nausea triggered by motion transmitted via the vestibulocochlear
nerve to the VC.
Chemoreceptor Trigger Zone (CTZ)
a. Nausea triggered by toxins in both the blood stream and CSF.
Cortex
a. Nausea triggered by sensory input, anxiety, meningeal irritation, and
increased intracranial pressure.
is the final common pathway for
vomiting. This center initiates coordinated responses from the
parasympathetic system and motor efferents to produce vomiting.
The Vomiting Center
7.
8. Non Pharmacological Treatment
Stay hydrated.
Avoid strong odors and other triggers.
Eat bland foods.
Avoid fatty or spicy foods.
Use over-the-counter (OTC) motion sickness medicines.
Eat small meals throughout the day instead of the large meals.
Eat slowly.
Don't let kids eat and play at the same time.
9. The factors which enable the clinician to discriminate among various
choices must be recognized. They are:
a. The suspected etiology of the symptoms
b. The frequency, duration, and severity of the episodes
c. The ability of the patient to use oral, rectal, injectable, or
transdermal medications
d. The success of previous antiemetic medications.
1. Although many approaches to the treatment of nausea and vomiting
have been suggested, antiemetic drugs (nonprescription and
prescription) are most often recommended.
2. These agents represent a variety of pharmacologic and chemical
classes, as well as dosage regimens and routes of administration.
10. Area Receptors Drugs
Chemo trigger zone Dopamine2 ,5-HT Haloperidol
Metoclopramide
Vomiting center Histamine1
Acetylcholine
Cyclizine
Levomepromazine
Hyoscine
Gut (chemoreceptors) 5-HT Levomepromazine
Adrs like severe constipation, muscle weakness, convulsions, loss of
hearing, rapid heartbeat, severe drowsiness, slurred speech,
psychological symptoms, like hallucinations or confusion
Patients may use histamine2-receptor antagonists in low doses to
manage simple nausea and vomiting associated with heartburn or
gastroesophageal reflux. Individual dosages may be used for brief
periods. Except for potential drug interactions with cimetidine, these
agents cause few side effects when used for episodic relief.
11. H2 Receptor antagonists
Antiemetic drugs from the antihistamic–anticholinergic category appear to
interrupt various visceral afferent pathways that stimulate nausea and
vomiting and may be appropriate in the treatment of simple nausea and
vomiting.
Diphenhydramine 25–50 mg every 4–6 h Tab, cap, liquid
Hydroxyzine 25–100 mg every 4–6 h prn I IM
Trimethobenzamide
300 mg three to four times daily
200 mg three to four times daily
Cap
IM
12. Primarily include: drowsiness, confusion, blurred vision, dry mouth, and
urinary retention, and possibly tachycardia, particularly in elderly patients.
Also as doses are increased or are more frequently administered
Patients with narrow-angle glaucoma, prostatic hyperplasia, or asthma
are at greater risk of complications from the anticholinergic effects of
these drugs.
Phenothiazine’s have been the most widely prescribed antiemetic agents
and appear to block dopamine receptors, most likely in the CTZ.
These agents may be most practical for long-term treatment and are
inexpensive in comparison with newer drugs.
Rectal administration is a reasonable alternative in patients in whom oral
or parenteral administration is not feasible.
13. Phenothiazine’s are most useful in adult patients with simple nausea and
vomiting.
There are numerous potential side effects with these medications,
including extrapyramidal reactions, hypersensitivity reactions with
possible liver dysfunction, bone marrow aplasia, and excessive sedation.
BUTYROPHENONES
Two butyrophenone compounds that have antiemetic activity are
haloperidol and droperidol. Each agent blocks dopaminergic stimulation of
the CTZ. Although each agent is effective in relieving nausea and vomiting
Prochlorperazine: 5–10 mg,3-4/day.
Promethazine:12.5-25 mg,4-6 hrs.
Thiethylperazine:10 mg,Tid.
14. 1. Haloperidol 1–5 mg every 12 h - Tab, liquid, IM, IV Rx
2. Droperidol 2.5–5 mg every 4–6 h - IM,
A. Dexamethasone-for CINV 10 mg prior to chemotherapy, repeat with 4–8
mg every 6 h for total of 4 doses-IV
B. Methylprednisolone-125–500 mg every 6 h for total of 4 doses IV
1. Lorazepam-0.5–2 mg-IV
CORTICOSTEROIDS
BENZODIAZEPINES