Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking fentanyl, it is important that your doctor knows:
- If you are pregnant or breastfeeding.
- If you have a problem with the way your liver works, or a problem with the way your kidneys work.
- If you have a sore mouth or diabetes. This is because some brands of fentanyl may not be suitable for you to take.
- If you have prostate problems or any difficulties passing urine.
- If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).
- If you have been told you have low blood pressure.
- If you have any problems with your thyroid or adrenal glands.
- If you have epilepsy.
- If you have a problem with your bile duct.
- If you have been constipated for more than a week or have an inflammatory bowel problem.
- If you have a condition causing muscle weakness, called myasthenia gravis.
- If you have recently had a severe head injury, or have a brain tumour.
- If you have ever been dependent on drugs or alcohol.
- If you have ever had an allergic reaction to a medicine.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.