Postoperative
The following adverse events have been associated with the use of naloxone hydrochloride injection in postoperative patients: hypotension, hypertension, ventricular tachycardia and fibrillation, dyspnea, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events. Excessive doses of naloxone in postoperative patients may result in significant reversal of analgesia and may cause agitation (see PRECAUTIONS and DOSAGE AND ADMINISTRATION: USAGE IN ADULTS, Postoperative Opioid Depression).
Opioid Depression
Abrupt reversal of opioid depression may result in nausea, vomiting, sweating, tachycardia, increased blood pressure, tremulousness, seizures, ventricular tachycardia and fibrillation, pulmonary edema, and cardiac arrest which may result in death (see PRECAUTIONS).
Opioid Dependence
Abrupt reversal of opioid effects in persons who are physically dependent on opioids may precipitate an acute withdrawal syndrome which may include, but is not limited to the following signs and symptoms: body aches, fever, sweating, runny nose, sneezing, piloerection, yawning, weakness, shivering or trembling, nervousness, restlessness or irritability, diarrhea, nausea or vomiting, abdominal cramps, increased blood pressure, tachycardia. In the neonate, opioid withdrawal may also include: convulsions, excessive crying, and hyperactive reflexes (see WARNINGS).
Adverse events associated with the postoperative use of naloxone hydrochloride injection are listed by organ system and in decreasing order of frequency as follows:
Cardiac Disorders: pulmonary edema, cardiac arrest or failure, tachycardia, ventricular fibrillation, and ventricular tachycardia. Death, coma, and encephalopathy have been reported as sequelae of these events.
Gastrointestinal Disorders: vomiting, nausea
Nervous System Disorders: convulsions, paraesthesia, grand mal convulsion
Psychiatric Disorders: agitation, hallucination, tremulousness
Respiratory, Thoracic, and Mediastinal Disorders: dyspnea, respiratory depression, hypoxia
Skin and Subcutaneous Tissue Disorders: nonspecific injection site reactions, sweating
Vascular Disorders: hypertension, hypotension, hot flushes, or flushing
See also PRECAUTIONS and DOSAGE AND ADMINISTRATION: USAGE IN ADULTS, Postoperative Opioid Depression.
{{section_name_patient}}
{{section_body_html_patient}}
Additional Resources
Chat online with Pfizer Medical Information regarding your inquiry on a Pfizer medicine or vaccine.
Speak with a Pfizer Medical Information Professional regarding your Pfizer medicine or vaccine inquiry.
Available 9AM-5PM ET Monday to Friday; excluding holidays.
Submit a medical question for a Pfizer medicine or a vaccine.
The submission will be reviewed during our standard business hours.
To report an adverse event related to a Pfizer product and you are not part of a clinical trial* for this medication, click the link below to submit your information:
Pfizer Safety Reporting Site
*If you are involved in a clinical trial for either product, adverse events should be reported to your coordinating study site.
If you cannot use the above website to report an adverse event related to a Pfizer medication, please call (800) 438-1985.
You may also contact the U.S. Food and Drug Administration (FDA) directly to report adverse events or product quality concerns either online at www.fda.gov/medwatch or by calling (800) 332-1088.