Discuss with the pharmacist the price of your medicine. If you are given a new prescription ask the doctor if he has any samples to try first before you have your prescription filled. Side effects are common with most pain medicines.
Constipation is a major side effect.
Drink water and fruit juices. Continue with your normal activity or exercise if possible. Ask your nurse, doctor, or pharmacist about starting a stool softener and a laxative if needed. Don't be embarrassed. This is normal.