Postoperative nausea and vomiting (PONV) is a common problem with reported rates ranging from 20% to 80%. It is second most common complication following surgery (first one is pain).

The etiology of PONV is complex, involving patient-related factors (such as sex, smoking status, and history of PONV), surgery-related factors (including the type of surgery), and anesthesia-related factors (such as the use of opioids and volatile anesthetics). In high-risk patients, PONV incidence can escalate to 80%. PONV if not treated may lead to complications like pulmonary aspiration, wound dehiscence, elevated intracranial pressure, and pneumothorax etc. It may also prolong post-anesthesia care unit stay time. Fourth consensus guidelines recommend antiemetic multidrug approach from different pharmacological classes.

Risk factors which contribute to increasing the incidence of postoperative nausea and vomiting, are younger age group (<50 years), female patients, history of motion sickness and postoperative nausea and vomiting, non-smokers and use of opioids.

To control or prevent PONV, various drugs have been used like ondansetron, granisetron.

(5-HT₃ antagonists), haloperidol (D₂ antagonist) & dexamethasone(cortico steroid), anticholinergics and antihistamines as a single drug or a combination of multiple drugs with variable results and side effects. Multiple studies show that use of single drug as an antiemetic in the prophylaxis of PONV is less effective than the combination.

Dexamethasone 4-8mg IV has been used alone or in combination to reduce the incidence of PONV.

The D2 receptor is known for precipitating PONV, even in surgical patients. Therefore, there is a hypothesis that drugs with D2 receptor antagonist properties, can be utilized for prophylaxis in the treatment of PONV.

Haloperidol (D2 receptor antagonist) has been used in small doses (1-2mg IV) for prevention and treatment of PONV alone or with other antiemetic like dexamethasone.

Amisulpride, a potent and selective dopaminergic D2 and D3 receptor antagonist, has been approved recently for prevention and treatment of PONV in lower doses (5mg). Its use has also been recommended with a combination of other antiemetic of different class for better result.

Thus both drugs, Haloperidol and Amisulpride, have been employed alone or with other antiemetic of different class to prevent postoperative nausea and vomiting (PONV). But, no study is available for comparing haloperidol and amisulpride alone or in combination.

In the present study it will be assessed that out of these two drugs having same class whichone is better in terms of  control of PONV and side effects.

An extensive search of the literature did not reveal any study comparing the effects of these two drugs in combination with dexamethasone to control the incidence of PONV. Therefore, the present study will be conducted to compare the prophylactic effects of a combination of dexamethasone and haloperidol with dexamethasone and amisulpride on incidence of PONV in laparoscopic cholecystectomy.