Page 6 - Pharma GIT L1

Drug Antiemetic mechanism Uses as antiemetic Adverse effects

1. Muscarinic blockers:  They block M1 receptors  Effective for nausea &  Anti-parasympathetic

 Scopolamine in vestibulo-cerebellar vomiting associated effects.

(hyoscine). pathway. with motion sickness.  Drowsiness.

 Hyoscine (drug of

choice).

2. H1 blockers:  They block H1 receptors  Effective for nausea &

 Diphenhydramine. in vestibulo-cerebellar vomiting associated ---

 Cyclizine. pathway. with motion sickness.

3. D2 antagonists:  They block D2 receptors  Vomiting caused by:  Dystonic reaction

 Metoclopramide. in CTZ.  Uremia. (phenothiazine more

 Domperidone.
 Phenothiazines  Radiation. than metoclopramide).

 Phenothiazines.
(thiethylperazine &  GI disorders.

promethazine) also

block H1 receptors.