Maintain your usual bowel movement schedule. Drink warm liquids. Nausea, Vomiting, Dry Mouth, Drowsiness, and Confusion Other serious side effects from pain medicines are rare, especially in people with cancer. If side effects occur, they are most likely to happen at the start of treatment or when doses are raised quickly. They are likely to go away after a few days.
Opiates can cause nausea and vomiting, drowsiness, dry mouth, and confusion.
The body builds up a tolerance to most side effects except constipation. Other medicines can help to stop these side effects. Ask the doctor or nurse for instructions for this. Nausea and vomiting usually last 2-3 days. Eat small amounts of food spaced throughout the day rather than several large meals.