 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  is used to prevent and treat nausea and vomiting related to certain conditions (such as motion sickness, or before/after surgery). It is also used to treat allergy symptoms such as rash, itching, and runny nose. It may be used to help you feel sleepy/relaxed before and after surgery or to help certain opioid pain relievers (such as meperidine) work better. The suppository form is used when medications cannot be taken by mouth.Promethazine is an antihistamine and works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. Its other effects (such as anti-nausea, calming, pain relief) may work by affecting other natural substances (such as acetylcholine) and by acting directly on certain parts of the brain. How to use Promethegan Suppository, Rectal Unwrap and insert one suppository rectally as directed by your doctor, usually 2 to 4 times daily. Remain lying down for a few minutes after using this medication, and avoid having a bowel movement for an hour or longer so the drug will be absorbed. The suppository is for rectal use only. For motion sickness, the first dose of promethazine should be used 30 to 60 minutes </s>