Anesthesia Pharmacology Chapter 21:  Gastrointestinal Pharmacology

Antiemetic Drugs

• Particularly useful for patients undergoing these procedures,with a history of nausea, vomiting or motion sickness, or obese patients:  opthalmological surgery, laproscopic surgery or gynecologic procedures

• If not desirable for preanesthetic medication, drugs may be administered IV at the conclusion of surgery.

• Some drug options:

  • Droperidol:

    • low doses; administered usually IV -- prevents postoperative nausea/vomiting

    • Some reports: droperidol better than either metoclopramide or domperidone

    • Droperidol reported useful as antiemetic for patients having cesarean section using spinal anesthesia

    •  Low doses: not always effective -- higher doses (at the end of surgery) may cause excessive recovery room sedation

  •  Metoclopramide (Reglan)

    • inconsistent, controversial for preoperative use

  •  Ondansetron: (Zofran)

    • 5-HT₃ receptor antagonist (serotonin antagonist)

    • Administration: IV, 4-8 mg {adult} before induction: highly efficacious in preventing postoperative nausea/vomiting

    • Should be used selectively

  • Other drugs:

    • phenothiazines (e.g.,prochlorperazine); hydroxyzine;diphenidol