Naltrexone

What is Naltrexone? 

Naltrexone can help with alcohol dependence and is a supportive therapy in maintaining abstinence from alcohol. It works by blocking opioid receptors in your brain and nervous system to reduce the pleasurable effects of alcohol. This will help to support your decision to stay alcohol-free. 

Please speak to your clinic doctor, nurse, or pharmacist if you would like more information about how Naltrexone works.

How to take Naltrexone

Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure. 

The initial dose of Naltrexone hydrochloride is half a tablet (25 mg) on the first day of treatment. After that, the usual dose is one tablet per day (50 mg). Your doctor may prescribe a different dosage depending on your individual needs. 

The amount of time you should take Naltrexone hydrochloride for will be decided by your doctor. The usual length of treatment is three months. However, in certain cases, a longer period of treatment may be beneficial.

How much food to take with Naltrexone

Naltrexone can be taken with or without food.

What if I forget to take a dose?

If you forget to take a dose at your usual time, take it as soon as you remember. If you do not remember until the following day, leave out the forgotten dose but make sure that you remember to take that day's dose. Do not take two doses together to make up for a forgotten dose.

Side effects

Naltrexone, like all other medicines, has some side effects, although not everybody gets them. Common side effects include: 

• headache
• feeling nervous/restless
• nausea
• dizziness 
• decreased appetite
• tummy (gastrointestinal) discomfort. 

The most serious side effects occurring in people taking Naltrexone hydrochloride include: 

• feeling depressed
• feeling suicidal
• attempted suicide
• hallucinations (seeing, hearing or sensing things that are not there). 

Although these effects are rare or uncommon, if you do experience any of these, then you must contact your doctor or pharmacist immediately for help and support.

If you experience any other side effects, and either they are troubling you or you develop any new symptoms after you start Naltrexone, tell your doctor, nurse or pharmacist who will tell you what to do. Further information is available in the manufacturer's printed information leaflet which is inside the medication pack.

What medicines should I avoid with Naltrexone? 

It is important to tell your doctor, nurse, and pharmacist of other medications (including over-the-counter medication) you are taking, and any new medication(s) started while you are on treatment to ensure they are compatible with Naltrexone. It is also important to inform them if you have had any previous allergic reaction(s) to medication.

Naltrexone must not be taken with opioids, and you will need to be “opioid-free” a minimum of 10 days before starting treatment. Otherwise, life-threatening opioid withdrawal symptoms can occur. 

Painkillers, some cold and flu medicines, cough mixtures and medicines against diarrhoea may contain weak opioids, so check with your local pharmacy if you are buying medicines over the counter for suitability with Naltrexone. 

If you require medical treatment, you must inform the responsible clinician that you are taking Naltrexone to ensure that if you do need opioids in an emergency, you get the right dose of pain relief. This is because the dose required may be higher than usual. You will need to be monitored closely because any symptoms including breathing difficulties (respiratory depression) may be stronger and longer lasting.