Domperidone is a dopamine antagonist used to treat nausea, vomiting, and gastrointestinal motility disorders.

Applications:

• Relieves nausea and vomiting.

• Treats gastroparesis by enhancing stomach emptying.

• Sometimes used to increase breast milk production (off-label).

Side Effects:

• Common: dry mouth, abdominal cramps, and headache.

• Serious (rare): heart rhythm disorders, especially in elderly or high doses.

Palonosetron Hydrochloride is a long-acting 5-HT3 receptor antagonist used to prevent nausea and vomiting.

Applications:

• Prevents acute and delayed nausea/vomiting from moderately to highly emetogenic chemotherapy.

• Also used for postoperative nausea and vomiting.

Side Effects:

• Common: headache, constipation, dizziness.

• Serious (rare): QT prolongation, hypersensitivity reactions.

Promethazine Hydrochloride is an antihistamine with antiemetic, sedative, and anticholinergic properties.

Applications:

• Treats nausea, vomiting, and motion sickness.

• Used as a sedative or for allergy symptoms.

• Sometimes used pre/post-surgery for nausea control.

Side Effects:

• Common: drowsiness, dry mouth, dizziness.

• Serious (rare): respiratory depression (especially in children), severe tissue damage if injected improperly.