 <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]  only. For motion sickness, the first dose of promethazine should be used 30 to 60 minutes before beginning travel. For allergies, this medication may be used once daily at bedtime to avoid being drowsy during the day. When used before surgery, promethazine may be used the night before or just before the procedure and may be continued afterwards as directed. The dosage is based on your age, medical condition, and response to treatment. In children, the dosage may also be based on weight. Do not increase your dose or use this medication more often than directed. Tell your doctor if your condition does not improve or if it worsens.The side effects of Promethegan Rectal: Drowsiness, dizziness, constipation, blurred vision, or dry mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away </s>