Naltrexone: Price, Dosage & Where to Buy

Naltrexone is an opioid antagonist, a medicine that blocks the effects of opioids, and is used to treat alcohol dependence. It is used as part of a wider addiction treatment plan, rather than as a treatment on its own. Naltrexone requires a prescription in the United Kingdom and is also used to block the effects of opioids in the treatment of opioid dependence.

Naltrexone is used to treat alcohol dependence. It is also used to block the effects of opioids as part of treatment for opioid dependence. These uses require an appropriate addiction management plan; the tablets have not been shown to offer a treatment benefit outside such a plan.

For alcohol dependence, the label describes treatment alongside other support. Factors linked with treatment outcomes include the type and duration of support, management of other health conditions, community support groups and regular use of the prescribed medicine. For opioid dependence, treatment forms part of a comprehensive management plan after opioids have been stopped.

The label lists 50 mg film-coated tablets for oral use. The label lists 50 mg once daily for most patients being treated for alcohol dependence. The label lists 50 mg once daily for up to 12 weeks in the trials supporting this use; other schedules or treatment durations were not evaluated in those trials.

The usual starting dose is 25 mg for opioid dependence. The label lists 50 mg a day thereafter if no withdrawal signs occur. Before treatment begins, the label requires patients who are dependent on opioids to be opioid-free, including tramadol.

It describes a minimum opioid-free interval of 7 to 10 days after dependence on short-acting opioids. People switching from buprenorphine or methadone may remain vulnerable to sudden withdrawal for as long as 2 weeks. A clinician assesses readiness for treatment, although neither an opioid urine test nor a naloxone challenge can completely rule out the risk of withdrawal.

Naltrexone belongs to a class called opioid antagonists. These medicines attach to opioid receptors, which are sites in the body where opioids normally act. They block these sites rather than activating them, reducing the effects of opioids.

In alcohol dependence, blocking opioid receptors can reduce the rewarding effects associated with drinking. This action supports an addiction treatment plan but does not replace other support. If opioids are still present in someone who is dependent on them, blocking their effects can trigger sudden withdrawal.

There are no adequate, well-controlled studies of naltrexone in pregnant women. Animal studies showed increased early fetal loss, but no evidence of birth defects during the period of major organ development at the doses studied.

The label states that use during pregnancy should be considered only when the potential benefit justifies the potential risk to the fetus. The label does not specify breastfeeding information; discuss this with a doctor or pharmacist.

A missed dose can reduce the protection against opioid effects. The label warns that people treated for opioid dependence may be at risk of overdose after a missed dose.

Do not double a dose to make up for a missed one. Ask a pharmacist or prescriber about resuming treatment, especially if opioids have been used in the meantime.

The label specifies storage at 20° to 25°C, with excursions permitted to 15° to 30°C. It also specifies a tight container to maintain quality. Keep the medicine out of the sight and reach of children.