Determining When to Use Opiate and Benzodiazepine Reversal Agents
Your patient has been receiving morphine via a patient-controlled analgesia (PCA) pump since yesterday due to severe pain following back surgery. When you checked her one hour ago, she seemed a little sleepy but roused easily when you called her name. You enter the room 45 minutes later and find her very sleepy and difficult to rouse. Her respiratory rate is six. Besides following hospital procedures for PCA medication administration, what reversal agent might you expect the physician to order? Is it naloxone (Narcan) or flumazenil (Romazicon)?
In this case, naloxone is the appropriate drug of choice. Medications such as morphine, hydromorphone (Dilaudid), fentanyl, oxycodone, demerol, codeine, methadone, and illegal drug substances like heroin, are all opioids. Naloxone is an effective opioid antagonist because it competes with opioids at their receptor sites, blocking the effects of these types of drugs.
How Much Should You Give?
The average adult dosing range for naloxone is 0.4-2 mg IM/IV/subcutaneous. It can be repeated every two to three minutes as needed. Keep in mind that naloxone has a short half-life (about one hour), so additional doses may be required even if the effects of the opioid seem to have been initially reversed.
What are the Side Effects of Naloxone?
Naloxone may cause nervousness or agitation and gastrointestinal upset. A rapid pulse and an increased systolic blood pressure may also occur when naloxone is given in high doses. There have also been reports of ventricular tachycardia and fibrillation.
Flumazenil is administered to reverse the effects of benzodiazepines. Flumazenil inhibits activity at benzodiazepine receptor sites, blocking the action of benzodiazepines. Benzodiazepines such as lorazepam (Ativan), alprazolam (Xanax) and diazepam (Valium) are prescribed for a sedative effect or to reduce symptoms associated with anxiety. Midazolam (Versed) is commonly used for procedures within health care facilities that require conscious sedation.
How Much Should You Give?
The average adult dose to reverse the effects of benzodiazepines used in conscious sedation procedures is 0.2 mg IV given over 15 seconds. If the effects of the medication are not sufficiently reversed, the physician will likely order 0.2 mg IV every 60 seconds until effective (with a maximum of 3 mg per hour).
What are the Side Effects of Flumazenil?
Flumazenil may cause agitation, dizziness, somnolence, confusion or seizures. Bradycardia, tachycardia and hypertension may also occur. Other side effects include headache, gastrointestinal upset, hiccups and abnormal vision.
Knowing the correct reversal agents for these medications is critical to safe nursing practice. Naloxone is used to reverse the effects of opiates while flumazenil is used to reverse the effects of benzodiazepines. Check your unit to see where these medications are stored and be sure that you know the reversal agent indicated for the various opiate and benzodizepines used in your unit.