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.

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.

Dimenhydrinate is an antihistamine primarily used to prevent and treat motion sickness and nausea.

Applications:

• Prevents and relieves nausea, vomiting, and dizziness from motion sickness.

• Used for vertigo and inner ear disturbances like Ménière’s disease.

Side Effects:

• Common: drowsiness, dry mouth, dizziness, and blurred vision.

• Serious (rare): confusion (especially in elderly), fast heartbeat, and urinary retention.