Used primarily as an antihistamine to treat allergic reactions, including symptoms like rash, itching, and runny nose. Commonly prescribed to prevent and control nausea and vomiting, especially after surgery or in motion sickness. Also used as a sedative to help with short-term sleep problems or to calm patients before medical procedures. Has mild anticholinergic and antiemetic properties, making it useful in managing certain types of vertigo and morning sickness, though not typically a first-line choice during pregnancy. Often combined with opioids or other analgesics to enhance pain relief and reduce nausea in palliative care settings.