The prescribing information for naltrexone hydrochloride tablets (50 mg) states that when withdrawal is precipitated abruptly by giving an opioid antagonist to an opioid-dependent patient, the resulting withdrawal syndrome can be severe enough to require hospitalization. This guide reports what that label says about opioids, overdose and opioid-containing medicines, and what two general pages say about calling for help in an overdose: an opioids page from the National Institute on Drug Abuse (NIDA) and a MedlinePlus page on poisoning. The label is for the 50 mg tablet, and the statements used from the two general pages are about overdose and poisoning in general, not about naltrexone, so nothing here says what applies at low doses.
Precipitated withdrawal and opioid-free intervals
The label for the 50 mg tablet says opioid-dependent patients, including those being treated for alcohol dependence, should be opioid-free (including tramadol) before starting treatment with that tablet. It recommends an opioid-free interval of a minimum of 7 to 10 days for patients previously dependent on short-acting opioids. It says patients transitioning from buprenorphine or methadone may be vulnerable to precipitation of withdrawal symptoms for as long as two weeks. It also tells prescribers to advise patients to be off all opioids, including opioid-containing medicines, for a minimum of 7 to 10 days before starting, in order to avoid precipitation of opioid withdrawal.
The same 50 mg tablet label's contraindications section lists patients receiving opioid analgesics, and patients currently dependent on opioids, including those maintained on opiate agonists such as methadone or partial agonists such as buprenorphine.
The information for patients section of the same label tells prescribers to advise all patients, including those with alcohol dependence, that it is imperative to notify healthcare providers of any recent use of opioids or any history of opioid dependence before starting naltrexone hydrochloride to avoid precipitation of opioid withdrawal.
Opioid-containing medicines, pain care and other drugs
The label for the 50 mg tablet says patients taking naltrexone hydrochloride may not benefit from opioid containing medicines, such as cough and cold preparations, antidiarrheal preparations, and opioid analgesics.
On pain management, the same 50 mg tablet label says that in a situation requiring opioid analgesia, the amount of opioid required may be greater than usual, and the resulting respiratory depression may be deeper and more prolonged. For an emergency in patients receiving fully blocking doses, it gives a suggested plan of management: regional analgesia, conscious sedation with a benzodiazepine, use of non-opioid analgesics or general anesthesia.
On other drugs, the label says studies of possible interactions between naltrexone hydrochloride and drugs other than opiates have not been performed, and that caution is advised if the 50 mg tablet is used together with other drugs.
Overdose and the time after stopping
The label for the 50 mg tablet says cases of opioid overdose with fatal outcomes have been reported in patients after discontinuing treatment, and that patients should be alerted that they may be more sensitive to opioids, even at lower doses, after treatment is discontinued. It also says any attempt to overcome the antagonism by taking opioids is especially dangerous and may lead to life-threatening opioid intoxication or fatal overdose.
The information for patients section of the same label also tells prescribers to advise patients that if they previously used opioids, they may be more sensitive to lower doses of opioids and at risk of accidental overdose should they use opioids after naltrexone hydrochloride treatment is discontinued or temporarily interrupted.
| Question | What the source says |
|---|---|
| Label for the 50 mg tablet: a known or suspected opioid overdose | Prescribers are told to emphasize the importance of calling 911 or getting emergency medical help in all cases, even if an opioid overdose reversal agent is administered. |
| NIDA opioids page: signs that a person is experiencing an overdose | The page says several signs can indicate that a person is experiencing an overdose and requires immediate medical attention, including unconsciousness or inability to wake up and slow or shallow breathing or difficulty breathing. |
| NIDA opioids page: if you suspect someone is overdosing | The page says to call 911. |
| MedlinePlus poisoning page: if you suspect someone has been poisoned | The page says to call your local poison control center at 1-800-222-1222 right away. The page does not mention naltrexone. |
What this does not tell you
The label statements above are about the 50 mg tablet. The NIDA and MedlinePlus statements are about overdose and poisoning in general, not about naltrexone. This guide does not say what applies at low doses. The label's opioid-free intervals, warnings and contraindications are written for the 50 mg tablet and its patients, and the pages above do not tell any reader what to do about a specific medicine or situation.
The label tells prescribers to advise patients to notify healthcare providers of any recent use of opioids. A licensed provider decides what applies to each person.