Pharmacology for Dentistry

258 Section 7/ Drugs Acting on GIT

mazine and is discussed in chapter ‘Psy-
chopharmacological agents’. Only remain-
ing compounds used as antiemetics are dis-
cussed here.

DOPAMINE ANTAGONISTS

PROCHLORPERAZINE

It blocks dopaminergic neurotransmission
in brain and exerts its action by blocking
dopamine receptors in brain. It is used in
nausea and vomiting.

Side effects include drowsiness, dry
mouth, skin rash, insomnia and other
cholinergic effects.

DOMPERIDONE

It causes antiemetic action by block-

ing dopamine (D 2 ) receptors and it also

increases gastric motility. It is absorbed

orally but bioavailability is 15% due to

first pass metabolism. It is completely

biotransformed and metabolites are ex-

creted in urine. It is used in nausea and

vomiting in postoperative period, drug

induced, radiation, uraemia, hepatitis,

peptic ulcer. It is also useful in reflex oe-

sophagitis.

Side effects include galactorrhoea, skin

rash and gynaecomastia.

Table 7.2.1: Classification of antiemetics.

I. Anticholinergics

Dicyclomine, hyoscine etc. Details are given in chapter ‘Anticholinergic agents’

II. Antihistaminics

Promethazine

Promethazine theoclate (AVOMINE)

Diphenhydrinate

Diphenhydramine

Doxylamine succinate etc. Details are given in chapter ‘Antihistaminic agents’.

III.Dopamine antagonists

Chlorpromazine 10-25 mg/day oral/IM

Triflupromazine 10 mg/day oral/IM

Prochlorperazine (STEMETIL) 5-10 mg/day oral/IM

Domperidone (DOMSTAL) 10-40 mg TDS

Metoclopramide (PERINORM) 10 mg TDS oral/IM

IV.5-HT 3 antagonists

Ondansetron (EMSETRON) Dose depends upon the patient’s requirement and stage.

Granisetron (GRANICIP)

V. Prokinetic agents

Cisapride (CIZA) 10-20 mg TDS

Mosapride (MOZA) 2.5-10 mg BD-TDS

Itopride (ITZA) 150 mg TDS