Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: certain pain medications (mixed narcotic agonist-antagonists such as pentazocine, nalbuphine, butorphanol), narcotic antagonists (such as naltrexone).
Other medications can affect the removal of fentanyl from your body, which may affect how fentanyl works. Examples include cimetidine, nefazodone, St. John's wort, azole antifungals including itraconazole/ketoconazole, calcium channel blockers such as diltiazem/verapamil, HIV drugs such as nelfinavir/ritonavir, macrolide antibiotics including clarithromycin/erythromycin, rifamycins including rifampin, certain anti-seizure medicines including carbamazepine, among others.
Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.
The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is used with other products that may also affect breathing or cause drowsiness. Therefore, tell your doctor or pharmacist if you are taking other products such as alcohol, allergy or cough-and-cold products, anti-seizure drugs (such as phenobarbital), medicine for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, other narcotic pain relievers (such as codeine), and psychiatric medicines (such as risperidone, amitriptyline, trazodone). Your medications or doses of your medications may need to be changed.
This medication may interfere with certain laboratory tests (including amylase/lipase levels), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.