1 interaction was found for the drugs you selected.
FENTANYL in Fentanyl Skin Patches
may interact with CIMETIDINE in Tagamet
Cimetidine may block the breakdown of fentanyl by the liver. If this happens, blood levels of fentanyl could be increased and this could cause an increase in side effects. Side effects that may occur with the use of fentanyl include drowsiness, dizziness, and confusion. Other more serious side effects include changes in blood pressure and heart rate, an abnormal heart rate, and breathing difficulties that can range from mild to life-threatening. If cimetidine and fentanyl are used together, your doctor may want to monitor you closely for side effects. If you are experiencing problems, it may be necessary to discontinue therapy with fentanyl. You may want to ask your healthcare provider about this potential interaction if you think you are having problems.
This interaction is poorly documented and is considered major in severity.