Naltrexone (or ‘blocker’) is a narcotic antagonist; it blocks the effects of heroin (and all other opiates) by blocking the opiate receptors within the brain. When taken orally, its effects last up to two days. It may also reduce cravings.
Naltrexone is extremely effective in blocking opiates but will not make the person feel ill if opiates are taken, they simply will have no effect and therefore are a waste of money. If opiates are used during the use of Naltrexone they will show up as positive in the urine sample you provide us. In contrast to this, if Naltrexone is given to a person who has not withdrawn from all opiates, he/she will experience sudden severe symptoms of opiate withdrawal and be very ill indeed. This may necessitate them being admitted to hospital. Some patients have “tried out” the implant to see if it works, but then stop after a few attempts. We strongly advise against this practice, as the purpose of the implant is to enable the person to make a commitment to opiate withdrawal.
When using Naltrexone you should have withdrawn from all opiates for at least 5 – 7 days before your first dose. Prior to having your first implant, it is important that you have already commenced on the oral medication. We stipulate a minimum of two days of oral Naltrexone (50mg tablets), this will ensure that you will not have an allergic reaction to the drug and you will also be unlikely to suffer any block effect (residual withdrawal symptoms) on implant insertion. You will be required to take a 50mg Naltrexone tablet on arrival at the Clinic.
You cannot become physically dependant on Naltrexone and it does not produce any euphoric effects.
Towards the end of the life of the implant the danger is that the patient could try to overcome the implant with heroin. While the implant is still releasing Naltrexone, it is extremely difficult to know exactly when the end of the implants life has come. Patients should therefore consider another implant if they are unsure of their ability to stay opiate free. Unfortunately, if a patient has been off heroin for a long amount of time, the body has become used to not having heroin therefore, he/she is more sensitive to heroin and what was the normal dose prior to implantation could now, in fact, kill him/her.
Taking Naltrexone means that all opiates are blocked and therefore, they are ineffective as a form of pain relief. Many forms of analgesia and cough preparations are opiate based – if in doubt ask the chemist. In the event of any accidents or post operative pain relief, there are many pain relieving drugs that can be used instead of opiates.
In tablet form Naltrexone has been used in Britain, America and Europe for over three decades. However, the George O’Neil double Naltrexone implants used in several countries worldwide remain unlicensed in the United Kingdom.