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.

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).

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

Applications:

• Prevents nausea and vomiting from chemotherapy and radiation therapy.

• Used postoperatively to manage nausea and vomiting.

Side Effects:

• Common: headache, constipation, dizziness.

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