Ondansetron is a 5-HT3 receptor antagonist used to prevent and treat nausea and vomiting.

Applications:

• Prevents nausea and vomiting from chemotherapy, radiation, and surgery.

• Sometimes used for severe morning sickness in pregnancy.

Side Effects:

• Common: headache, constipation, dizziness.

• Serious (rare): QT prolongation, allergic reactions, serotonin syndrome (when combined with other serotonergic drugs).

Hyoscine/Scopolamine Hydrobromide is an anticholinergic used to prevent motion sickness and treat nausea.

Applications:

• Prevents motion sickness-related nausea and vomiting.

• Used for postoperative nausea and in palliative care to reduce secretions.

Side Effects:

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

• Serious (rare): confusion, hallucinations, and urinary retention.

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.