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Nausea & Vomiting

A ntipmptirc

CAUSES OF NAUSEA & YOMITING

Chemoreceptor Trigger Zonę	Vestibular	Cortical	Peripheral
drugs •    opioids •    chemoTx •    etc... biochemical •    tCa^ •    renal failure •    liver failure sepsis radiotherapy	tumor opioids	anxiety association t ICP	radiotherapy chemotherapy GI irritation •    inflammation •    obstruction •    paresis •    compression

Antiemetics

•    Nonpharm Rx= weak tea, flattened carbonated drinks, Gatorade & pedialyte (children), crackers dried toast

•    Nonprescription antiemetics = to prevent motion sickness (Ginger drops, Peppermint oil)

-    minimal effect on severe vomiting from anticancer agents, radiation, and toxins.

-    take 30 min. before traveling

•    Dimenhydrinate (Vomex), meclizine HCL (Antivert), diphenhydramine HCL (Dimedrol)

-    SE = drowsiness, dryness of mouth, constipation

Chemoreceptor Trigger Zonę and Emetic Center

□    V    □

Atropinę Dropcridol NK-1 RA ” mAAłAA VOCA)

Anlagonist    Q    /\

5-HTj RAs    Promcthazine

Agonist    O    /\

5-HTj    Histaminę

Receptor Site

□    V    □

Muscarinic    Dopairiine (Dj)    Substancc P

GI tract distcnsinn

Highcr cenieni (vision, taste)

Pharyns

Watcha MF. Whitc PF. Anesthcsiology. 1992;77:162-184.

Antiemetics

•bismuth subsalicylate (Pepto-Bismol) - act directly on gastric mucosa to suppress vomiting - liąuid & chewable - taken for gastric discomfort & diarrhea

•    Phosphorated carbohydrate (Emetrol) Hyperosmolar carbohydrate -> gastric pH i

•    Antiemetics l^st trimester of pregnancy -> possible harm to fetus.

Non-pharmacological methods should be used & OTC antiemetics avoided -> unless N & V become life threatening to mom & baby. Then use trimethobenzamide (Tigan).

\K