Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR CLOSELY: Coadministration with inhibitors of CYP450 3A4 may increase the plasma concentrations of butorphanol according to the product labeling. However, pharmacokinetic data are not available. Increased butorphanol concentrations could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. Conversely, discontinuation of a CYP450 3A4 inhibitor could decrease butorphanol plasma concentrations, decrease opioid efficacy, and possibly even lead to a withdrawal syndrome in patients who had developed physical dependence to butorphanol.

MANAGEMENT: Patients receiving butorphanol with potent or moderate CYP450 3A4 inhibitors should be carefully monitored, and dosage adjustments made accordingly as needed. This is particularly important when an inhibitor is added after a stable dose of butorphanol has been achieved. Patients and/or their caregivers should be advised to seek medical attention if potential signs and symptoms of toxicity occur, such as dizziness, confusion, fainting, extreme sedation, unresponsiveness, bradycardia, slow or difficult breathing, and shortness of breath. When discontinuing CYP450 3A4 inhibitors, monitor patients closely at frequent intervals and consider increasing the opioid dosage if needed to maintain adequate analgesia or if symptoms of opioid withdrawal occur.

Do not use alcohol or medications that contain alcohol while you are receiving treatment with butorphanol. This may increase nervous system side effects such as drowsiness, dizziness, lightheadedness, difficulty concentrating, and impairment in thinking and judgment. In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur. With certain long-acting formulations of narcotic pain medication, consumption of alcohol may also cause rapid release of the drug, resulting in high blood levels that may be potentially lethal. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. Do not use more than the recommended dose of butorphanol, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.